PURPOSE:Pre-competition weight control for combat sports athletes may alter body composition and fatty acid metabolism. Probiotics have shown potential to regulate overall metabolism; however, their specific effects on fatty acid metabolism during weight control in athletes remain unclear. METHODS:Thirty-two combat sports athletes participating in the 4-week weight reduction period were assigned to either the probiotic group (Group E) or the placebo group (Group C). Body composition, lipid profiles, and fatty acid metabolism were measured before and after the 4-week weight reduction phase. RESULTS:All the athletes experienced a decrease in body weight, body mass index (BMI), body fat percentage, and muscle mass following the 4-week weight loss intervention. Notably, a more significant reduction in body fat percentage (p < 0.05) was observed, along with lower levels of triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), specifically in Group E. Weight loss intervention resulted in increased levels of short-chain fatty acids (SCFAs), specifically acetic acid, propionic acid, and butyric acid. Notably, Group E exhibited higher mean values for SCFAs compared to Group C (p < 0.05). Additionally, the serum levels of γ-linolenic acid and 8,11,14-eicosatrienoic acid were significantly reduced in Group E (p < 0.05). In contrast, the majority of free fatty acids (FFAs) showed significant increases, with greater magnitudes of change observed in Group C (p < 0.05). CONCLUSION:Probiotic supplementation can improve body composition, enhance SCFAs levels, and decrease circulating FFAs in combat sports athletes, suggesting that probiotics may have a beneficial impact on pre-competition weight management. TRIAL REGISTRATION NUMBER:chiCTR2400079908 (Reg Date:2024-01-16).
BACKGROUND:Exercise-induced muscle damage (EIMD) resulting from eccentric contractions leads to transient impairments in muscle function. Essential amino acids (EAAs) stimulate muscle protein synthesis and may support recovery following damaging exercise. However, limited research has examined the effects of EAAs on muscle function following eccentric plantar flexor exercise. The purpose of this study was to examine the effects of EAA supplementation on indirect markers of muscle and musculotendinous recovery following EIMD. METHODS:Thirty-six recreationally active males (age: 21.2 ± 2.7 years) were randomly assigned to an EAA group (10 g of EAAs), placebo (10 g of maltodextrin), or control (no supplementation). Supplements were consumed 30 minutes before and immediately after an eccentric plantar flexor protocol (4 × 50 repetitions followed by one set to failure) and during the 72 hours recovery period. Indirect markers of muscle damage were assessed pre-exercise, immediately post-exercise, and 24, 48, and 72 hours post-exercise, consisting of perceived soreness (NPRS), pain pressure threshold (PPT), calf muscle thickness and Achilles tendon thickness (ultrasound), and calf circumference. RESULTS:The eccentric protocol elicited responses consistent with EIMD, including increased soreness (p < 0.001), increased calf muscle thickness and circumference (p < 0.001), and reduced PPT (p = 0.018). EAA supplementation attenuated soreness at 24 hours compared with placebo. Calf muscle thickness increased following exercise in both groups; however, swelling returned to baseline by 72 hours in the EAA group but remained elevated in placebo (Condition × Time, p < 0.001). Achilles tendon thickness decreased immediately post-exercise (p = 0.005) but was not influenced by supplementation. CONCLUSIONS:EAA supplementation modestly reduced soreness and was associated with faster recovery of muscle swelling but did not influence tendon morphology within 72 hours.
Sodium bicarbonate is an ergogenic extracellular buffering agent that has recently garnered more interest because novel formulations purported to mitigate gastrointestinal symptoms, thereby increasing use with high-profile athletes. The effects of sodium bicarbonate on various aspects of exercise performance have been explored in hundreds of scientific articles. However, questions persist about aspects of its effectiveness and the potential side effects associated with the extracellular buffer. In this review, we provide answers to several questions related to sodium bicarbonate supplementation. These questions covered include: (1) What are sodium bicarbonate's proposed mechanisms for enhancing performance? (2) Does sodium bicarbonate cause gastrointestinal symptoms, and why? (3) What are the different ways in which sodium bicarbonate can be ingested, and how does this affect blood bicarbonate changes and exercise performance? (4) How does sodium bicarbonate affect performance in short-duration exercise (≤10 min)? (5) How does sodium bicarbonate affect performance in long-duration exercise, and should it be used before and during such events? (6) Is there a potential rationale for sodium bicarbonate use at altitude? (7) Is it worth ingesting sodium bicarbonate for exercise in the heat? (8) When is the best time to take sodium bicarbonate before exercise? When does blood bicarbonate peak in the blood? (9) What happens when sodium bicarbonate is taken after exercise instead of before? (10) Should sodium bicarbonate be taken throughout training, or can it be taken just during the day of a competition/game/race? Are there benefits of taking sodium bicarbonate for training adaptations? (11) Which sports mainly benefit from sodium bicarbonate supplementation? (12) Should one worry about the sodium dose? (13) How does extracellular buffering compare to intracellular buffering agents such as beta-alanine? (14) Is there a possible placebo effect with sodium bicarbonate? (15) Are the ergogenic effects of sodium bicarbonate sex-specific? To address these questions, we conducted an evidence-based review of the literature on sodium bicarbonate supplementation, with contributions from several invited experts. Comprehensive answers are provided alongside suggestions for future research.
BACKGROUND:Little is known about the energy costs of recreational skiing, snowboarding, and cross-country skiing activities in young adults. Investigating the intensity of such activities for promoting skiing in public health and exercise contexts is needed. This study measured the heart rate (HR), oxygen uptake (VO2), and respiratory quotient (RQ) of recreational Alpine skiing, snowboarding, and simulated cross-country skiing (roller skiing) in young adults (17-25 y). METHODS:Three cross-sectional studies were performed. Alpine skiing (study 1, n = 13, 11 males, 2 females) and snowboarding (study 2, n = 13, all males) were performed on a ski slope rated intermediate in difficulty. Each skier completed one run and was guided by a researcher to maintain a common speed. Simulated cross-country skiing (study 3, n = 13, 8 males, 5 females) was performed while the roller skiing on a laboratory treadmill at 0% incline with increasing velocities per stage. Two trials were conducted: free skate (combined V1, V2) and the classic technique. HR was monitored by telemetry. VO2 and RQ were measured by portable indirect calorimetry. METs were computed as VO2 ml.kg-1.min-1 divided by 3.5. RESULTS:The energy cost in METS for men and women combined was highest for simulated cross-country skiing (free skate, 10.57 ± 0.53; classic, 8.62 ± 0.75) than Alpine skiing (7.76 ± 1.18) and snowboarding (7.38 ± 2.55). RQ was highest for Alpine skiing (0.96 ± 0.10) than other skiing modes (on average, 0.87 to 0.88). Exercise HR was higher in the free skate (164.52 ± 13.58) and Alpine skiing (153.41 ± 20.54) than classic skiing (149.56 ± 12.68) and snowboarding (139.39 ± 41.96). CONCLUSIONS:Recreational Alpine skiing, snowboarding, and simulated cross-country skiing are vigorous-intensity activities with an energy cost exceeding 6 METs in young adults. This study provides empirical, protocol-specific MET values for these activities, which validated and refined the existing estimates for these activities in the Adult Compendium of Physical Activities, offering an empirical basis for more precise energy expenditure assessment in recreational skiing.
BACKGROUND:Adequate nutrition knowledge (NK) and dietary intake are important to the development in Youth Development Phase (YDP) academy footballers, helping to fuel sporting performance and promote long-term health. However, these areas remain under-researched within English Premier League (EPL) academy settings. This study aimed to investigate NK and energy intake (EI) in YDP academy players, including key stakeholders' knowledge, within a single Category 1 Academy. METHODS:Eighty-three EPL Category 1 YDP academy players (U11s = 17, U12s = 16, U13s = 8, U14s = 17, U15s = 10, and U16s = 15; 14 ± 2 years), 6 academy coaches, 1 YDP sports scientist and 31 caregivers' knowledge was assessed through the 89-item Knowledge and Sports Questionnaire (NSKQ). Twenty-five EPL Category 1 YDP academy players (U12s: n = 8, U13s: n = 9, U14s: n = 5, and U16s: n = 3; 13 ± 2 years) dietary intake was also assessed using an estimated written 7-day food diary collected during the in-season (2023/2024 season, March to May 2023). RESULTS:Collectively, academy players (33% ± 8%), caregivers (40% ± 13%), and coaches (41% ± 9%) scored poorly on NK. Academy players reported sub-optimal energy intake (1742 ± 314 kcal·day-1 and 38.5 ± 11.4 kcal·kg⁻¹·day⁻¹), accompanied by poor intake of daily carbohydrate (<5 g·kg-1·d-1), and fiber (<25 g/day) referenced to recommended daily intakes. Daily protein intake (1.7 ± 0.5 g·kg-1·d-1) exceeded the recommended intake for adolescent footballers, while fat intake (27% ± 6%) expressed as a percentage of total dietary intake (TDI) was within the guidelines. NK was not correlated with absolute EI, (r(23) = -.187, p = .371, or EI adjusted to BM, (r(23) = .204, p = .329. CONCLUSION:The results indicated poor NK and suboptimal dietary intake in EPL Category 1 academy players accompanied by low knowledge among stakeholders.
Background The prevalence of obesity and increased fat in the chest and abdomen in women and hormonal changes, can affect female fertility. The present study aims to investigate the effect of exercise training combined with cinnamon supplementation on chest and abdominal circumference, as well as sex hormones, in overweight and obese women.Methods Twenty-six inactive overweight and obese women were randomly allocated to an exercise (E; n = 13) and exercise plus cinnamon supplementation (E+S; n = 13) group. Both groups completed a 4-week exercise program three times weekly, while the E+S group additionally received cinnamon supplementation three times weekly. Chest and abdominal circumferences and serum concentrations of estradiol, progesterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were assessed before and after the intervention.Results Significant pre-to-post reductions in chest and abdominal circumference were observed in both groups (all p ≤ 0.005). Estradiol, progesterone, and FSH concentrations increased, whereas LH concentrations decreased significantly in both groups (all p ≤ 0.005). However, between-group comparisons revealed a significant difference only for chest circumference (p = 0.003), with no significant group differences in abdominal circumference or any reproductive hormone concentration (all p > 0.05).Conclusion Both groups showed favorable changes in anthropometric and reproductive hormone measures following the 4-week study period. However, the significant between-group difference was limited to chest circumference, providing no clear evidence that cinnamon supplementation conferred additional benefits for abdominal circumference or reproductive hormone profiles beyond those observed with exercise. These findings highlight the potential relevance of exercise-based interventions while warranting confirmation in larger, adequately powered trials.
BACKGROUND AND OBJECTIVES:Modern soccer, characterized by its intermittent high-intensity nature, requires a combination of explosive power and aerobic endurance. This physiological demand results in substantial metabolic load, oxidative stress, and disruption of recovery processes in players. Multi-target nutritional supplements may therefore provide critical support in maintaining performance and accelerating recovery. This qualitative review synthesizes current evidence regarding the efficacy of melatonin, gut-axis interventions (prebiotics, probiotics, and synbiotics), magnesium, sodium pyruvate, and purple grape-derived products on performance and recovery outcomes in soccer players. METHODS:Twenty-two interventional studies conducted on soccer players were systematically extracted and qualitatively synthesized following PRISMA 2020 reporting guidelines. Methodological quality and risk of bias were assessed using design-specific tools, including the Cochrane Risk of Bias 2 (RoB 2) tool for randomized controlled trials and the ROBINS-I framework for non-randomized intervention studies. Overall certainty of evidence was evaluated using an adapted GRADE framework. Particular attention was directed to study design, dosage and timing protocols, performance and biochemical outcomes, and methodological limitations, with emphasis placed on linking mechanistic evidence with applied performance and recovery outcomes. RESULTS:Melatonin, administered either nocturnally or prior to exercise, was associated with reductions in oxidative stress markers and upregulation of antioxidant enzymes, contributing to attenuation of short-term performance decline; however, its effects on maximal performance indices were inconsistent. Prebiotic, probiotic, and synbiotic interventions enhanced mucosal immunity and reduced the incidence and duration of upper respiratory tract infections (URTI) as well as delayed onset muscle soreness (DOMS). Certain combined formulations-particularly those co-administered with protein or spirulina-also demonstrated improvements in body composition and muscular strength. Magnesium supplementation alone showed limited and inconsistent benefits in athletes without deficiency, although combined formulations indicated potential improvements in buffering capacity and anaerobic performance. Short-term sodium pyruvate supplementation supported ATP-PCr system resynthesis and enhanced repeated sprint performance. Purple grape-derived products increased serum antioxidant capacity and, in some participants, improved endurance performance. LIMITATIONS AND CONCLUSIONS:Key limitations across studies included small sample sizes, protocol heterogeneity, and a lack of standardized mechanistic biomarkers. Overall, these supplements may support performance and recovery in soccer players; however, larger-scale, field-based randomized controlled trials are required to establish precise, evidence-based operational strategies.
BACKGROUND:Overweight and obesity have emerged as a global epidemic, significantly impacting human health. Traditional usage and growing scientific evidence suggest that Coleus forskohlii extract (Forcslim) may aid in reducing excess body weight and fat. This study aimed to evaluate the efficacy and safety of Forcslim supplementation in overweight individuals. METHODS:A quasi-randomized, double-blind, placebo-controlled clinical trial was conducted in 60 overweight subjects aged 20-70 years over a period of 12 weeks. The participants were assigned to receive either Forcslim or placebo. The key outcome measures included body weight, body mass index (BMI), body composition, and anthropometric parameters. Additionally, lipid profile parameters and safety markers (including metabolic, hepatic, and cardiovascular indicators) were assessed throughout the study duration. RESULTS:Compared to the placebo group, the Forcslim group showed significant reductions in waist circumference (-1.83 cm; p < 0.01) and body weight (-1.93 kg; p < 0.001). Significant improvements in anthropometric parameters were observed exclusively in the Forcslim group. Furthermore, triglyceride (TG) levels were significantly reduced (p < 0.01), while high-density lipoprotein (HDL) levels showed a significant increase (p = 0.001). No clinically significant changes were observed in metabolic markers, liver and muscle enzyme levels, heart rate, blood pressure, or reported adverse effects, indicating a favorable safety profile. CONCLUSIONS:Forcslim demonstrated significant anti-obesity effects, including reductions in body weight, waist circumference, and improvements in the lipid profile. These findings suggest that C. forskohlii extract supplementation may serve as a safe and effective alternative to synthetic anti-obesity drugs.
BACKGROUND:Golf is a prolonged, moderate-intensity sport requiring sustained physiological stability to manage cumulative stress and maintain performance. Although carbohydrate intake is commonly used to reduce fatigue, rapidly absorbed sugar-induced rapid blood glucose fluctuations may induce volatile arousal and latent metabolic stress. Isomaltulose, a slow-digesting disaccharide, provides a steadier glucose supply compared with sucrose. This exploratory pilot study examined the effects of isomaltulose intake on physiological stress markers, glycemic dynamics, and subjective responses during a competitive 18-hole golf round. METHODS:Twenty-three male collegiate golfers were randomized to either the isomaltulose group (ISO; n = 12) or the sucrose group (CON; n = 11) in a double-blind controlled trial. Participants consumed gummies containing isomaltulose or sucrose immediately after each hole (12.1 g carbohydrate per hole; total carbohydrate intake: 217.5 g). Primary outcomes were salivary stress markers [cortisol, testosterone, and dehydroepiandrosterone sulfate (DHEAS)] levels. Secondary outcomes included interstitial glucose concentration measured via continuous glucose monitoring, subjective assessments (i.e. sleepiness, relaxation, and concentration), and golf performance (18-hole score). Between-group comparisons at each time point were conducted using planned Welch's t-tests. RESULTS:No significant between-group differences were observed for 18-hole score (p = 0.38) or mean interstitial glucose concentration (p = 0.20). However, exploratory analyses revealed distinct hormonal variations; salivary DHEAS and testosterone levels were higher in the ISO group during the latter half of the round (p < 0.05), whereas both declined in the CON group. Regarding glycemic variability, the ISO group demonstrated a more stable glucose profile with a medium effect size for lower standard deviation (ISO: 14.7 ± 1.9 vs. CON: 16.7 ± 4.6 mg/dL; d = 0.58), although this difference was not significant. Conversely, subjective outcomes diverged; the CON group reported significantly greater subjective arousal (wakefulness and relaxation) (p < 0.01) relative to the ISO group. CONCLUSIONS:In conclusion, continuous intake of isomaltulose-containing gummies during an 18-hole golf round was associated with differences in selected physiological markers, including DHEAS and testosterone concentrations. However, these findings were not accompanied by improvements in objective golf performance outcomes compared with sucrose-containing gummies. Isomaltulose may influence glycemic dynamics and hormonal responses during prolonged golf play; however, the practical significance of these effects remains exploratory. Further studies with larger sample sizes and appropriate repeated-measures frameworks are needed to determine whether such physiological changes translate into meaningful performance or recovery benefits.
BACKGROUND:This study investigated the effects of carbohydrate mouth rinsing (CHOMR) on various psychophysiological, kinematic, and technical actions during 4-a-side small-sided soccer games (SSGs). METHODS:In a randomized, crossover, double-blind design, 16 young male soccer players (age: 15 ± 1 years; height: 172.6 ± 7.0 cm; body mass: 57.8 ± 7.9 kg) participated in two 4-a-side SSGs separated by one week following either CHOMR or placebo (PLA). During each SSGs, heart rate (HRmean, %HR, and HRmax), rating of perceived exertion (RPE), enjoyment, visual analogue scale (VAS) to perceived mental fatigue, mood states, total distance (TD), high-speed running distance (HSRD), average metabolic power (AMP), high metabolic load distance (HMLD), sprint distance (SD), acceleration (ACC), deceleration (DEC), and technical actions (e.g. passing, tackling, shooting, and interceptions) were assessed. RESULTS:Compared with PLA, CHOMR resulted in significantly higher RPE (p = 0.025, g = 0.86) and significantly lower VAS scores (p = 0.010, g = -0.71). In addition, the CHOMR condition showed significantly higher values for interceptions, successful tackles, unsuccessful tackles, unsuccessful shots, and goals (p < 0.05, g = 0.96-2.02), whereas block values were significantly higher in the PLA condition. There were no statistically significant differences in HRmean, %HR, HRmax, enjoyment, TD, HSRD, AMP, HMLD, SD, ACC, DEC, successful passes, unsuccessful passes, successful shots, or mood states between the conditions (p > 0.05). CONCLUSION:The current study findings suggest that CHOMR may enhance selected technical actions and lower VAS scores during 4-a-side SSGs, although it was also associated with higher RPE and did not alter the kinematic responses. In conclusion, CHOMR was associated with higher RPE, lower mental fatigue, and selective improvements in technical actions, with no significant effects on kinematic variables or HR.
BACKGROUND:Previous studies indicate that sports drinks may improve rehydration, compared to water, an effect likely achieved by manufacturing sports drinks to contain carbohydrates and sodium. However, there is a growing preference for natural products and a "food first" approach to sports nutrition. Fruit juices naturally contain similar concentrations of carbohydrates to sports drinks, but fruit juices may produce a more stable blood glucose profile. Fruit juices also naturally contain electrolytes, particularly potassium, but their potential as effective rehydration alternatives to sports drinks, which have higher sodium concentrations, is not well understood. This study compared the rehydration efficacy and glucose responses following consumption of a 100% fruit juice (Raw Hydrate®; FRU), a glucose-based sports drink (SPO), and water (WAT) after exercise-induced hypohydration. Importantly, rehydration beverages were matched for water volume, rather than total volume, to ensure that any potential differences in water balance were not due to unequal water volumes between trials, a limitation affecting previous rehydration research. METHODS:After familiarization, 17 adults (age: 28 ± 8 years; BMI: 23.8 ± 2.9 kg/m2) completed three trials in a randomized cross-over design. The participants cycled in the heat (~35°C) to induce ~2% body mass loss (BML), then rehydrated over a 1 h period in a laboratory (~21°C) with a water volume equivalent to 150% of BML from either FRU, SPO, or WAT. This was followed by an additional 4 h of seated rest (5 h rehydration period), when blood glucose was measured (0, 0.25, 0.5, 0.75, 1, 1.5, and 2 h after beverage consumption), and all urine produced was collected. RESULTS:During the 5 h rehydration period, there was no effect of trial on total urine volume (FRU: 1266 ± 403 mL, SPO: 1338 ± 361 mL, WAT: 1394 ± 360 mL; P = 0.156) or water retention (FRU: 42 ± 12%, SPO: 37 ± 10%, WAT: 35 ± 11%; P = 0.059). The blood glucose area under the curve differed by trial (P < 0.001), with all beverages significantly different from each other (FRU: 10.12 ± 0.72 mmol/L/2h, SPO: 12.48 ± 1.34 mmol/L/2h, WAT: 7.90 ± 0.47 mmol/L/2h; P < 0.003). CONCLUSION:Rehydration efficacy was similar between all beverages, but each elicited a distinct glycemic response. For sports drink consumers seeking a natural alternative or implementing a "food first" nutritional strategy, switching to a 100% fruit juice will not compromise rehydration effectiveness, but may elicit a lower blood glucose response. Although, it should be noted that an additional three participants were withdrawn from the study because of gastrointestinal issues after consuming the 100% fruit juice. This was likely a product of the present study's design, where a large volume of 100% fruit juice (average ~2,300 mL) was consumed in a short period of time (1 h). Whilst this is a commonly used study design to robustly assess the rehydration efficacy of different beverages, future studies should distribute fluid intake over a longer duration, in order to improve ecological validity and reduce the risk of gastrointestinal issues.
BACKGROUND:This study aimed to investigate the effects of folic acid supplementation combined with resistance training on body composition, homocysteine (Hcy), and lipid-related biomarkers in adult males. METHODS:Forty healthy male college students were recruited and randomly divided into four groups: control, resistance training (RT), folic acid supplementation (FA), and resistance training + folic acid supplementation (RF) condition (n = 10 each). The intervention lasted for 8 weeks, preceded by a 1-week testing period. The RT and RF followed the same resistance training program. The FA and RF participants consumed 0.4 mg folic acid daily, whereas the control participants received one appearance-matched placebo tablet daily. Body composition, Hcy concentration, blood lipids, and folic acid concentration were measured before and after the 8-week intervention. Data were analyzed using SPSS 22.0. Descriptive statistics are presented as mean ± standard deviation (SD). Paired t tests were used to compare pre- and postintervention data within groups, and one-way ANOVA was used to compare differences between groups. A significance level of P < 0.05 was used. RESULTS:Regarding body composition, the RF produced the greatest increase in skeletal muscle mass (SMM; + 4.79 ± 2.42 kg), which was significantly larger than the increases observed in the control (+0.96 ± 1.50 kg), FA (+1.03 ± 1.68 kg), and RT (+0.91 ± 1.12 kg) (all P < 0.01). Body fat mass (BFM) decreased most in the RF (-1.49 ± 1.40 kg), differing significantly from the control (+0.24 ± 1.71 kg; P < 0.01) and FA (+0.04 ± 1.18 kg; P < 0.05). Additionally, the RF showed a significantly greater decrease in body fat percentage (BFP) than the FA (P < 0.05). In terms of blood biomarkers, Hcy decreased significantly in the RF relative to the control and RT (both P < 0.05), and HDL-C increased more in the RF (+0.21 ± 0.24 mmol/L) than in the control (-0.01 ± 0.12 mmol/L; P < 0.01) and FA (+0.02 ± 0.16 mmol/L; P < 0.05). No significant between-group differences were detected for folic acid concentration, TC, TG, or LDL-C. CONCLUSIONS:Folic acid supplementation combined with resistance training was associated with greater gains in skeletal muscle mass, greater reductions in body fat mass, lower Hcy, and higher HDL-C than either intervention alone. These favorable biomarker changes may contribute to a reduced risk of cardiovascular disease; however, these findings should be interpreted as preliminary rather than definitive evidence of cardiometabolic benefit.
BACKGROUND:Theoretically, CrM supplementation during a weight loss and exercise intervention may help older individuals promote more optimal changes in body composition, training adaptations, and cognition. To determine whether CrM affects body composition, cognitive function, and/or markers of health in untrained and trained middle-aged and older adults. METHODS:Seventy-three healthy sedentary adults selected whether to participate in a non-exercise or exercise and diet intervention and were then randomized, in a double-blind and counterbalanced manner, to 2 × 5 g/d of maltodextrin placebo (PLA) or CrM. Sixty-four adults aged 45-65 years (54.5 ± 6.2 years, 84.5 ± 21.3 kg; 40 females and 24 males) completed the 12-week intervention and were analyzed. At 0, 6, and 12 weeks, participants had DXA body composition determined, donated fasting blood samples, and completed a battery of cognitive tests and questionnaires. general linear models (GLMs), multivariate and univariate, with repeated measures and mean changes from baseline with 95% confidence intervals, and Chi-squared analyzes were used. RESULTS:CrM supplementation without exercise training and diet intervention increased lean tissue mass, strength, and muscular endurance while promoting favorable changes in selected blood lipids, HbA1c, and selected markers of cognitive function and memory. Creatine supplementation during an exercise and weight-loss diet intervention increased lean tissue mass, promoted a greater reduction in body fat percentage, and improved muscular strength, endurance, and selected markers of cognitive function and memory. Supplementation was well-tolerated. CONCLUSION:CrM supplementation with and without exercise and diet intervention may help middle-aged and older adults maintain muscle mass and strength while favourably affecting selected markers of health and cognitive function. Individual cognitive and biomarker findings should be interpreted as exploratory. Clinical trial registration: ISRCTN83081058.
Background Cognitive impairment and dementia are rapidly increasing among older adults, with limited pharmacological treatments available. Modifiable lifestyle factors, particularly diet and physical activity, are promising preventive targets. Although the Mediterranean diet and regular exercise individually benefit cognition, their combined effects and underlying mechanisms remain poorly synthesised.Methods The systematic review followed PRISMA-ScR guidelines and involved database searches on PubMed, Embase, Web of Science, Cochrane, and CNKI. Study inclusion criteria were defined using the PICO framework.Results The Mediterranean diet supplies polyphenols and fatty acids that reduce oxidative stress and inflammation, and support neurotrophic and neuroendocrine functions, thus protecting the brain. Meanwhile, physical activity boosts cerebral blood flow, improving antioxidant delivery and stimulating neurotrophic factors like BDNF, IGF-1, and VEGF to enhance brain plasticity. Together, these approaches act synergistically to balance energy metabolism, lower inflammation, and activate antioxidant defenses, thereby preserving brain homeostasis and boosting cognitive function.Conclusions Evidence suggests a synergistic effect of the Mediterranean diet and physical activity in preserving cognitive function in older adults. The diet directly supports cognitive health and provides essential nutrients for exercise-induced neuroregeneration. Physical activity, in turn, increases cerebral blood flow, improving nutrient delivery and stimulating neurotransmitter release. This interaction enhances brain plasticity, establishing a virtuous cycle between nutrition, exercise, and cognitive health.
BACKGROUND:Optimal body composition (BC) is essential for athletic success, influencing performance outcomes. Athlete-specific nutrition interventions are important for improving BC and enhancing performance, but evidence is limited, especially in track and field athletes. This study aimed to assess the effect of athlete-specific dietary guidance on BC in Sri Lankan track and field athletes. METHODS:A 16-week trial was conducted with 30 athletes, 15 in each group: intervention (IG) and control (CG). The IG received athlete-specific dietary guidance through individual consultations at weeks 0, 4, and 8, along with weekly nutrition advice. BC was assessed using anthropometry, bioelectrical impedance analysis (BIA), and dual-energy X-ray absorptiometry (DEXA). Muscle strength, as a component of physical fitness, was assessed via handgrip strength (HGS). RESULTS:Fourteen participants from each group completed the study. The IG demonstrated a significant decrease in fat mass percentage (FM) derived from BIA (Pre: 21.80 ± 7.0% vs. Post: 17.25 ± 5.8%; Change: -4.55 ± 1.2%; p = 0.003), while the CG demonstrated a no significant change (Pre: 18.87 ± 7.84% vs. Post: 19.60 ± 5.84%; Change: + 0.73 ± 3.0%; p = 0.475). The body fat percentage derived from DEXA also demonstrated significant reductions in the IG (Pre: 21.60 ± 7.1% vs. Post: 17.30 ± 6.0%; Change: -4.30 ± 1.1%; p = 0.005), and the CG exhibited a no significant change (Pre: 18.84 ± 3.9% vs. Post: 19.61 ± 6.5%; Change: + 0.77 ± 0.4%; p = 0.367). Fat-free mass (FFM) derived from DEXA increased in IG (Pre: 42.29 ± 6.0 kg vs. Post: 46.57 ± 6.4 kg; Change: +4.28 ± 0.4 kg; p < 0.001) when compared to CG (Pre: 39.13 ± 11.4 kg vs. Post: 38.05 ± 11.7 kg; Change: -1.08 ± 0.3 kg; p = 0.051). The IG showed significantly better HGS. CONCLUSIONS:Athlete-specific dietary guidance significantly improved BC and physical fitness among track and field athletes. TRIAL REGISTRATION:This trial was registered in the Sri Lanka Clinical Trials Registry (SLCTR/2024/013) under Universal Trial Number (UTN) U1111-1304-8890 on 10 April 2024.
BACKGROUND:Creatine is among the most extensively studied dietary supplements in sports nutrition, yet real-world supplementation patterns, knowledge, and outcomes remain poorly characterized. Prior survey research has focused on competitive athletes and younger male samples, even as the evidence base has expanded to support applications in healthy aging, cognition, and female physiology. Whether use patterns, perceived benefits, and adverse effects among the broader and more diverse population now using creatine align with trial evidence, and whether they differ by gender identity and age, has not been systematically assessed. METHODS:An online cross-sectional survey was distributed to approximately 110,000 users of a supplement tracking application (SuppCo, Inc.) with recorded creatine use, yielding 2,178 analyzable responses from individuals reporting current or past-12-month creatine use (1,077 women and 1,101 men; median age, 55 years). The survey assessed supplementation patterns, goals, creatine knowledge (six-item battery scored via generalized partial credit item response theory [IRT] modeling), side effects, satisfaction, and information needs. Multivariable analyses included logistic regression for perceived benefit, modified Poisson regression for side-effect prevalence, and OLS regression for satisfaction, with Benjamini-Hochberg correction for multiple comparisons. As an exploratory analysis, a mixed graphical model (MGM) characterized conditional associations across measurement domains, and IRT discrimination parameters were combined with network centrality to identify candidate keystone misconceptions. RESULTS:Despite 98% intending to continue supplementation and mean satisfaction of 7.8/10, only 55% perceived benefit. Cognitive performance was the most commonly endorsed goal (67.8%) yet showed the largest within-person unmet-expectation rate (64.4% of cognitive-goal endorsers did not perceive a matched cognitive benefit; McNemar p < .001). Women reported higher self-reported side-effect prevalence (PR = 1.48; 95% CI 1.15-1.91) and lower odds of perceived benefit (OR = 0.66; 95% CI 0.55-0.80) than men, with a flatter dose-benefit slope (women × dose OR = 0.65; 95% CI 0.53-0.80). Knowledge of creatine, scored via IRT theta from a five-item battery, was the most consistent positive correlate across all primary outcomes: perceived benefit, satisfaction, the positive experience composite, and above-common dosing. An exploratory IRT-by-network analysis identified kidney damage as the candidate keystone misconception, with the highest IRT discrimination and above-median cross-domain centrality; the network also identified long-term safety beliefs as conditionally associated with intent to continue, consistent with the hypothesis that safety beliefs track behavioral persistence. CONCLUSIONS:In this middle-aged, gender-balanced community sample of creatine users, behavioral loyalty was high yet substantial knowledge gaps, unmet benefit expectations, and self-reported side-effect burdens disproportionately affected women and older adults, who together comprise an increasingly important share of contemporary creatine users. Knowledge appeared as the most consistent positive correlate of supplementation experience, suggesting education may be a tractable lever for improving real-world outcomes; misconceptions about kidney safety and long-term tolerability may warrant particular attention as educational targets. The cognitive expectation gap may reflect a dose-translation issue rather than absence of efficacy. These findings generate hypotheses for prospective evaluation of education, gender-tailored dosing guidance, and expectation-setting interventions in real-world creatine users.
BACKGROUND:Resting Metabolic Rate (RMR) is measured in sport settings for health monitoring and nutrition planning; however, interpreting repeated measures requires an understanding of typical day-to-day variability under habitual, free-living conditions. This study quantified intra-individual variability in RMR among weight-stable strength-trained athletes, examined the impact of data processing approaches, and established protocol-specific least significant change (LSC) thresholds under ecological conditions. METHODS:A repeated-measures design was used to quantify intra-individual variability in RMR in 13 weight-stable strength-trained athletes (8 male, 5 female). RMR was measured on five consecutive mornings using the Parvo Medics TrueOne 2400 metabolic cart with a Hans Rudolph mouthpiece under standardized conditions. Breath-by-breath data were processed using multiple cleaning approaches to evaluate their impact on RMR estimates, with the most reliable method retained for analysis. Intra-individual variability was quantified and used to derive protocol-specific LSC thresholds. RESULTS:Session averaging produced the lowest intra-individual variability in RMR (CV: 3.4 ± 1.4%) compared with alternative data cleaning approaches. Mean RMR was 26.9 ± 1.4 and 29.1 ± 1.7 kcal·kgFFM-1·day-1 in males and females, respectively. The group-level LSC was 2.9 ± 1.2 kcal·kgFFM-1·day-1 (10.4 ± 4.2%), representing the magnitude of change required to exceed expected within-subject variability under the conditions of this protocol. Fat-free mass (FFM) was positively associated with both absolute RMR and day-to-day variability, whereas prior-day training load and protein intake showed no clear association with RMR variability. CONCLUSIONS:Notable intra-individual variability occurs in repeated RMR measurements in strength-trained athletes under applied conditions. Meaningful interpretation of change requires protocol-specific reliability estimates to distinguish true physiological change from expected day-to-day variation. Session averaging improves measurement consistency and is recommended for mouthpiece-based indirect calorimetry systems. RMR should be interpreted relative to individual and context-specific variability rather than universal thresholds.
BACKGROUND:Sustaining cognitive and physical performance under extreme environmental conditions is critical for special operation forces (SOF). Hyperthermia negatively impacts cognitive function due to reductions in cerebral blood flow, substrate availability, thermal tolerance, and increased cardiovascular strain. While ketone monoester have demonstrated beneficial effects on cognition, their efficacy during exercise-heat stress remains unexplored. METHODS:Seventeen endurance-trained males (age = 23.8 ± 5.2 y; VO2max = 58.6 ± 3.2 ml·kg-1·min-1) completed a randomized, double-blind, counterbalanced, crossover study. Participants ingested 4 mg·kg-1 caffeine combined with either a ketone monoester (KET; (R)-3-hydroxybutyl-(R)-3-hydroxybutyrate) or an energy-matched carbohydrate control (CHO; Cluster Dextrin™). Each experimental visit consisted of 90 minutes of loaded treadmill exercise in the heat (34 °C, 45% RH) followed by a high-intensity time-to-exhaustion (TTE) test. Cognitive performance (1-back, 2-back, Dynavision reaction time [RT], object hit and avoid [OHA]), blood metabolites, average heart rate, and core body temperature (CBT) were assessed before, during, and after exercise and analyzed using linear mixed-model ANCOVA. TTE duration and maximal heart rate during TTE were analyzed using paired-samples t tests. RESULTS:For cognitive performance, KET demonstrated significantly greater 1-back total accuracy (+2.8%, p = 0.001) and target accuracy (8.9%, p < 0.001) relative to CHO across all timepoints, Additionally, KET increased overall target discrimination (d': + 0.3, p = 0.001) irrespective of task condition and timepoint. For 2-back, no overall between-condition differences were observed in total or target accuracy across time points, although task difficulty remained higher than 1-back performance overall. No between-condition differences were observed for RT or OHA outcomes. For blood metabolites, KET significantly increased circulating BHB concentrations relative to CHO at mid- and post-exercise (+1.7 and + 3.5 mmol·L-1, respectively; both p < 0.001) and reduced blood glucose by 14.7 and 27.6 mg·dL-1 at the same time points (p = 0.002 and p < 0.001, respectively). For average heart rate, there was a main effect of time, with heart rate lower during the first 45-minutes exercise bout than the second (-7.7 beats·min-1, p = 0.01), but no effect of condition (p = 0.453). CBT increased over time in both conditions (p < 0.001) but did not differ between KET and CHO (p = 0.065). TTE duration was significantly longer following KET than CHO (8.9 ± 4.6 vs 7.0 ± 2.1 min; p = 0.04), whereas maximal heart rate during TTE did not differ between conditions (p = 0.112). CONCLUSIONS:Ketone monoester ingestion combined with caffeine improved select aspects of working memory and resulted in a significantly longer time-to-exhaustion compared with carbohydrate control following prolonged, loaded exercise in the heat. However, these effects were not universal across all cognitive outcomes, as no between-condition differences were observed for 2-back, RT, or OHA. Notably, despite performance differences, average heart rate, maximal heart rate during TTE, and core temperature did not differ. Together, these findings suggest that ketone monoester and caffeine co-ingestion may support specific cognitive and physical aspects of performance during sustained exercise-heat stress without altering cardiovascular or thermal strain.
BACKGROUND:β-hydroxy-β-methylbutyrate (HMB) supplementation may support aerobic capacity and isometric strength. Its utility has been studied mainly for 3 g HMB·day-1. Therefore, new and personalized HMB supplementation protocols should be verified. This parallel randomized placebo(PLA)-controlled triple-blind study was designed to evaluate the effects of liquid HMB free acid supplementation during customary training/lifestyle or combined with high-intensity functional training (HIFT) on aerobic fitness, physical capacity, and isometric strength indices following an incremental cycling test (ICT) in trained (TR) and untrained (UTR) males. METHODS:Fifty-three TR (29.1 ± 7.7 years; body mass (BM): 84.8 ± 10.0 kg; FFM: 71.2 ± 8.9 kg) and 37 UTR participants (32.3 ± 7.6 years; BM: 90.1 ± 16.5 kg; FFM: 68.4 ± 10.3 kg) completed two 3-weeks periods, including: 1) supplementation period (SUP)-ingesting 90 mg·kgFFM -1·day-1 of either HMB or PLA and performing usual training (TR) or lifestyle (UTR), and 2) HMB/PLA ingestion combined with the additional HIFT stimuli (2 units per week; SUP + EX). TR_HMB, TR_PLA, UTR_HMB, UTR_PLA groups were analyzed. Testing visits were performed at baseline (T BAS ), and after the SUP (T SUP ) and the SUP + EX (T SUP+EX ). The following evaluations were performed: BM and body composition, ICT, and maximal voluntary isometric contraction (MVIC) of the lower limb. A general linear model was conducted to examine the main effects and interaction of treatment (supplementation) (HMB/PLA), training status (TS; TR/UTR), and baseline values (BAS) over repeated measurements (T BAS , T SUP , T SUP+EX ). The following interactions were tested: visit × treatment; visit × TS; visit × treatment × TS; and visit × treatment × TS × BAS. One-way ANOVA or Kruskal-Wallis ANOVA (non-normal distribution) were conducted to examine differences in the degree of absolute changes (ΔT SUP -T BAS , ΔT SUP+EX -T SUP , ΔT SUP+EX -T BAS ) in the measured indices between studied subgroups. RESULTS:Increases (T SUP+EX -T BAS ) in VO2MAX (p = 0.024), time to the anaerobic threshold (AT; p < 0.001), VO2AT (p = 0.001), power output at the AT (p < 0.001), heart rate at the AT (p < 0.001), time to the respiratory compensation point (RCP; p < 0.001), VO2RCP (p < 0.001), power output at the RCP (p < 0.001) were higher in TR_HMB vs. TR_PLA. Simultaneously, in UTR, greater increases in TimeRCP (p = 0.001) and PowerRCP (p = 0.002) occurred with HMB supplementation compared to PLA. MVIC indices did not change due to the treatment. CONCLUSIONS:Supplementation of high HMB dose combined with HIFT increases aerobic fitness and capacity, especially RCP and AT indices. HMB supplementation combined with HIFT evoked significant favorable changes in a greater number of the evaluated aerobic fitness and capacity indices in trained compared to untrained individuals. Thus, untrained individuals probably need greater exercise stimuli (>2 HIFT units per week) and a longer intervention period to obtained greater benefits. These findings suggest that incorporating liquid HMB supplementation at a dose of 90 mg·kgFFM -1·day-1 alongside HIFT is an effective strategy to enhance aerobic fitness and capacity in trained individuals, while further research including longer intervention periods and greater training stimuli is needed to determine the optimal supplementation protocol for untrained individuals.
BACKGROUND:A longitudinal controlled intervention study aimed to assess the impact of a nutrition education program on Lebanese athletes' nutritional knowledge, eating habits, body composition and performance. METHODS:A sample of 198 athletes was divided into an intervention group (IG) and a control group (CG). The intervention group followed a 4-month intensive nutrition education program set to ensure sufficient time for meaningful learning and behavior change, while remaining short enough to maintain participant engagement and minimize dropout. The athletes' nutritional status and performance were assessed before and after the intervention using a validated food frequency questionnaire, knowledge and eating habits questionnaires, four 24-h recalls, a beep test to estimate VO2 max and one-repetition maximum tests to measure muscle strength. Paired-sample t-tests, McNemar's test and Mixed Factorial Anova test were conducted to examine the effects of the nutritional education program on nutrition knowledge, hydration status, eating habits and performance within both groups. RESULTS:The nutritional knowledge score increased in both groups after the intervention, with a significantly greater improvement of 23% observed in the IG (from 62.6% to 77.1%; p < 0.001). The IG also demonstrated a notable improvement in eating habits compared to the CG (p < 0.001). Following the intervention, body fat percentage decreased from 21.3% ± 6.0% to 18.8% ± 6.0% (p < 0.001), and waist circumference significantly decreased in the IG (p < 0.001). The IG increased their consumption of vegetables (p < 0.001) and yogurt (p = 0.002) and decreased their intake of sugars (p < 0.001) and sunflower oil (p = 0.002). Improvements in both aerobic and strength performance were observed in the IG (p < 0.001). CONCLUSIONS:The nutrition education program led to significant improvements in athletes' nutritional knowledge and eating habits, which consequently resulted in enhanced performance.
