Previous research supports the role of 17-β-estradiol (E2) and progesterone (P4) in altering lipid oxidation (LOx) rates during aerobic exercise, but it has yet to be determined if LOx is altered between menstrual cycle (MC) phases following strength-based resistance exercise (RE). This study examined post-exercise LOx rates in eumenorrheic females, following a bout of RE during the early-follicular, low hormone phase (LHP) and mid-luteal, high hormone phase (HHP). Twenty-two (age: 25.1 ± 5.7 years; fat-free mass: 44.7 ± 4.9 kg; relative strength: 1.2 ± 0.2) well-trained females completed a repetition maximum (RM) test for the back squat, bench press, and deadlift. Participants then completed one resistance exercise session consisting of five sets of 3 repetitions at 80%-85% 1RM for each exercise during the first 5 days of the participants' MC (LHP) and once during the calculated mid-luteal phase (HHP). Metabolic testing occurred at baseline (BL) and again immediately post, 30, 60, and 90 min post-exercise. Despite expected hormonal differences in E2 (LHP = 1.53 ± 0.58 pg/mL; HHP = 1.88 ± 0.48 pg/mL) and P4 (LHP = 230.51 ± 152.55 pg/mL; HHP = 545.22 ± 295.72 pg/mL), there were no differences in LOx at any timepoint between MC phase (p > 0.05). However, RE increased absolute LOx rates by ∼49% compared to BL across the entire metabolic collection period (p < 0.05), with the highest LOx rates recorded at 60 min post-exercise (0.077 ± 0.016 g·min-1, p < 0.001). These findings suggest that RE acutely increases LOx rates above BL levels in well-trained, eumenorrheic females post-exercise, regardless of MC phase.

Protein turnover may be influenced by menstrual cycle hormones and hormones from oral contraceptives (OCs) and hormonal intrauterine devices (H-IUDs), yet data are limited. This study evaluated whole-body protein turnover in 40 healthy, active females (eumenorrheic = 15; OC = 13; H-IUD = 12) tested once in low- and high-hormone phases. Using a [15N]alanine tracer, net protein balance, synthesis, breakdown, and nitrogen flux were measured. No group differences were observed. Protein breakdown and nitrogen flux were higher in the low-hormone phase in the total sample. These small hormone cycle phase-related changes in protein breakdown and nitrogen flux may guide active women's nutrition and exercise strategies.

PURPOSE:Athlete monitoring has emerged as a common method to track athlete status and adjust training for optimal performance. Despite the influx of monitoring-related resources at the collegiate level, actual training load modifications are largely anecdotal. This prospective cohort study investigated relationships between previous day training load, objective nightly recovery, and next-day subjective wellness and max speed (MS) in elite soccer athletes across a collegiate season. METHODS:Twenty-six collegiate female soccer athletes were tracked across the duration of their season (2024-2025) for training load (wearable global positioning systems monitors), objective nightly recovery (wearable recovery rings), next-day subjective wellness (morning wellness survey), and MS performance. RESULTS:Previous day training load measures of distance and high-speed running were significant predictors of variables related to nightly objective sleep recovery, next day subjective readiness, and next day speed performance. High-speed running models consistently performed better than total distance for predicting changes in recovery, wellness, and MS. CONCLUSIONS:Numerous associations between previous day training load and objective and subjective measures increase accessibility of female athlete monitoring methods for applied practitioners. Although the magnitudes of coefficients vary, the consistency of significant findings across monitoring methods provides utility for continuous and comprehensive athlete monitoring, demonstrating the importance of subjective readiness measures beyond traditional performance metrics, while also addressing the paucity of literature in elite female athletes.

Type 1 diabetes (T1D) is characterized by insulin deficiency and impaired glucose homeostasis. Exercise is recommended for individuals with T1D, with moderate-intensity continuous training (MICT) favored due to concerns of hypoglycemia with high-intensity interval training (HIIT). PURPOSE:The extent to which these exercise strategies alter metabolomic signatures of macronutrient metabolism in T1D is unknown. The current study evaluated glycemic variability and metabolomic responses around energy-matched HIIT and MICT in individuals with T1D. METHODS:Fourteen adults with T1D (7 females, 7 males) completed three conditions in a randomized crossover design: HIIT (10 1-minute intervals at 90% VO 2 peak), MICT (15-20 min steady-state cycling at 65% VO 2 peak), and no exercise (control, CON). Twenty-four-hour glycemic responses via continuous glucose monitor and metabolomics assessed by blood samples before, after, and 1 h after exercise by targeted mass spectrometry and nontargeted gas chromatography-mass spectrometry. RESULTS:Average whole-day glucose levels were higher on the day of HIIT (167.48 ± 66.96 mg/dL; group × time P = 0.021) and MICT (166.46 ± 61.35 mg/dL; group × time P = 0.039) compared with CON (150.43 ± 61.69 mg/dL) with no difference between HIIT and MICT (group × time P = 0.999). Area under the curve for glucose was not different between HIIT, MICT, and CON on the day of exercise (group × time P = 0.961). After MICT, long-chain acylcarnitine C14:2 (0.06 ± 0.04 µmol/L) was higher than after HIIT (0.04 ± 0.02 µmol/L; group × time P = 0.008), with C16:1 (group × time P = 0.046) and C16:2 (group × time P = 0.021) higher than CON. CONCLUSIONS:In adults with T1D, HIIT and MICT elevated average glucose on the day of exercise, with greater fatty acid oxidation after MICT. These data support the metabolic safety and distinct fuel utilization of both exercise modalities in T1D.

This paper synthesizes current research on women's football to develop comprehensive, evidence-informed nutritional strategies tailored to the specific demands of the sport. Four key themes are addressed: (1) energy requirements in women's football; (2) macronutrient and nutrient-timing applications around training and match play, including an illustrative case study; (3) supporting a player with inadequate energy intake, including an illustrative case study; and (4) nutritional considerations relating to fluctuations in female sex hormones. Rather than providing another descriptive narrative review, this synthesis translates research findings into practical strategies for implementation in real-world performance environments. Adequate energy availability is identified as a fundamental nutritional priority. Carbohydrate and protein intake are emphasized as essential for sustaining training quality, supporting recovery, and maximizing match performance. Nutrient timing is highlighted as a critical determinant of in-season performance and effective match preparation. Consideration is also given to the influence of hormonal fluctuations on thermoregulation and menstrual cycle-related symptoms, alongside nutritional strategies to mitigate these effects. This synthesis underscores the importance of individualized nutritional strategies to optimize health, performance, and return-to-play outcomes in women footballers.

ABSTRACT:Moore, SR, Joniak, KE, Ladan, AN, Britton, ME, Cantu, EI, Hirsch, KR, Hackney, AC, and Smith-Ryan, AE. Does hormonal phase affect acute high-intensity interval training exercise? An evaluation of performance and fatigue. J Strength Cond Res 40(9): e901-e908, 2026-Fatigue is a critical factor in high-intensity interval training (HIIT) performance, which may vary across female hormonal phases and with changes in work-rest ratio. This study evaluated exercise performance (average power [AP], peak power [PP]) and fatigue (power drop [PD; peak power-minimum power/time]) between 2 work-matched HIIT protocols during the low- (LHP) and high-hormone phases (HHP). In total, 35 women (age: 24.3 ± 6.1 years) completed 4 HIIT trials in randomized orders of hormonal phase and HIIT protocol: HIIT 1:1 : 10 rounds of 1 minute on/1 minute off; HIIT 2:1 : 20 rounds of 20 s on/10 s off. High-intensity interval training 2:1 resulted in significantly higher AP (HIIT 1:1 -HIIT 2:1 Δ-36.6 ± 2.3 W; p < 0.001) and PP (Δ-34.1 ± 4.0 W; p < 0.001) than HIIT 1:1 , with no significant difference between phase differences. When analyzed by protocol, HIIT 2:1 demonstrated greater PD in the LHP than in the HHP (Δ11.4 ± 4.7 W; p = 0.020), with no significant difference between phases for HIIT 1:1 . When collapsed across protocols, PD was significantly greater in the LHP than in the HHP (LHP-HHP Δ11.2 ± 4.9 W·s -1 ; p = 0.031). High-intensity interval training power performance (AP, PP) was influenced by the work-rest ratio, but not hormonal phase, with significantly higher power output in HIIT 2:1 . Greater PD during the LHP suggests physical fatigue may vary across hormonal phases, but the lack of HIIT 1:1 PD differences between phases may indicate augmented recovery with the equal work-rest ratio, particularly during the LHP. Although power performance was minimally different between phases, altering work-rest ratio may be a consideration for maintaining power outcomes and managing fatigue across female hormonal cycles, particularly in the LHP.

INTRODUCTION:Lipid oxidation (LOx) is a relevant physiological process linked to metabolic health. Despite growing interest in resistance training (RT) as a means to influence substrate utilization, LOx responses in females remain poorly characterized, with no study examining whether lower- and upper-body RT elicits different LOx patterns during the recovery period following exercise. This distinction may be relevant because lower-body exercises involves greater fat-free mass (FFM) and energy expenditure, whereas upper-body exercises recruit less FFM, potentially influencing metabolic effects. PURPOSE:To determine if LOx rates after exercise differ between lower- and upper-body RT in well-trained females. METHODS:Twenty-two females (age: 25.4 ± 5.6 yr, FFM: 44.5 ± 4.9 kg, mean relative strength: 1.1 ± 0.2) completed repetition-maximum tests in the barbell back squat (BS) and bench press (BP). From these, an equated volume-load (sets × repetitions × load) was determined using 65% 1 repetition-maximum of participants' BS and BP. Metabolic testing was completed before either the BS or BP, then immediately (IP), 30-, 60-, and 90-min postexercise. RESULTS:No significant differences were found between BS or BP LOx rates ( P > 0.05). LOx relative to FFM averaged 1.57 ± 0.4 mg·kg -1 FFM·min -1 across both exercises from IP to 90-min postexercise, representing a 45% and 65% increase from baseline in the BP and BS, respectively. At 90-min post-RT, LOx reached 1.78 ± 0.37 mg·kg -1 FFM·min -1 (SEM = 0.08) for the BS and 1.65 ± 0.31 mg·kg -1 FFM·min -1 (SEM = 0.07) for BP, with no between-condition differences ( P > 0.05). Resting energy expenditure was not different between conditions ( P > 0.05), with a pooled average of 1.04 ± 0.13 kcal·min -1 from IP to 90-min post-RT. CONCLUSIONS:These data demonstrate that RT, differing in FFM but not volume-load, stimulates comparable LOx rates and resting energy expenditure responses during the postexercise recovery period. These findings support versatility in exercise prescription, indicating that RT of different muscle regions can produce similar acute metabolic outcomes.

PURPOSE:The aim of this overview of reviews was to determine the impact of resistance training (RT) prescription on muscle function and hypertrophy, utilizing evidence synthesis methods. It updates the American College of Sports Medicine 2009 Position Stand, "Progression models in resistance training for healthy adults." DATA SOURCES:Ovid MEDLINE(R) ALL, Ovid Emcare, Ovid Embase, Cochrane Database of Systematic Reviews, EBSCOhost SPORTDiscus, and Web of Science Core Collection current to October 2024. ELIGIBILITY CRITERIA:Eligible systematic reviews synthesized randomized trials of healthy adults (≥18 yr) who completed RT (≥6 wk; range: 6-52 wk), compared with a group that completed no exercise or an alternative RT program, and reported the change in muscle function, size, or physical performance. RESULTS:We synthesized data from 137 systematic reviews (>30,000 participants). Compared with no exercise (control), RT significantly improved muscle strength, size (hypertrophy), power, endurance, contraction velocity, gait speed, balance, and multiple physical function outcomes. Few RT prescription (RTx) variables affected primary adaptations. However, voluntary strength was enhanced by lifting heavier loads (≥80% one-repetition maximum), through a complete range of motion, for 2-3 sets, at the beginning of training sessions, and ≥2 sessions/wk. Muscle hypertrophy was enhanced by higher volumes (≥10 sets/wk) and eccentric overload. Power was enhanced by moderate loads (30%-70% one-repetition maximum), low-to-moderate volume (≤24 repetitions⋅sets), Olympic-style weightlifting, and power RT (fast concentric phase). Power RT enhanced physical function. Training to momentary muscle fatigue, equipment type, exercise complexity, set structure, time under tension, blood flow restriction, and periodization did not consistently impact training outcomes. CONCLUSIONS:Healthy adults should perform progressive RT, with variable prescription consistent with our findings, to improve muscle function, size, and physical performance. Muscle strength, hypertrophy, power, and certain components of physical function can be enhanced by manipulating the RT variables highlighted.

Critical power (CP) is derived from the hyperbolic relationship between power output and time to exhaustion (TTE) and delineates severe-intensity exercise from the heavy-intensity domain. Fluctuations in endogenous and exogenous female sex hormones may influence this power–duration relationship. This study examined CP and subjective fatigue between low-hormonal (LHP) and high-hormonal (HHP) phases of the menstrual cycle (MC) in eumenorrheic (EUM), intrauterine device (IUD), and oral contraceptive (OC) using females. Thirty-five participants (mean ± SD: age: 24.3 ± 6.1 yrs, weight: 65.2 ± 7.0 kg) completed a randomized crossover design. Performance outcomes (CP [W], anaerobic work capacity [W´; J], TTE [sec], and total work [J]) were evaluated from three TTE trials at 110

Despite continued success, female athletes are still underresourced and minoritized in research and applied spaces. This has translated to disparate injury and health outcomes among female athletes resulting from a sport infrastructure built on male physiology. The purpose of this article is to propose an evidence- and experience-based menstrual cycle (MC) phase-based training model for practitioners working with elite female athletes in team sport. Here, we provide physiological rationale, privacy considerations, and best practices to support female-centric training. The following model proposes periodization based on a theorized capacity of adaptation rather than acute performance or symptomology alone because evidence suggests that performance changes across the MC may be highly individual. In addition, strength and conditioning programs are formulated to balance stressors and recovery in the pursuit of optimal adaptation, irrelevant of acute exercise performance. Finally, we identify future directions for applied practitioners and researchers, and the potential need for collaborative innovations between the communities. Creating a training model based on the physiology and experience of female athletes communicates to female athletes that they belong in sport and are worthy of our time, attention, and resources to improve their health, safety, and performance now and through active retirement.

The purpose of this study was to compare dominant and non-dominant leg fat-free mass (FFM) estimations and inter-limb leg FFM asymmetry detection between multi-frequency bioelectrical impedance analysis (MF-BIA) and dual-energy X-ray absorptiometry (DXA) in career firefighters. Sixty-one male career firefighters (age = 31.9 ± 7.4 years; stature = 179.0 ± 7.6 cm; body mass = 89.9 ± 17.4 kg) volunteered for the investigation and reported to the laboratory on one occasion. Leg FFM was estimated by measuring the conduction impedance measured through the corresponding sensing and injecting electrodes for MF-BIA and by outlining both legs into regions of interest for DXA. Inter-limb leg FFM asymmetry was calculated by subtracting the non-dominant limb FFM from the dominant limb FFM, dividing it by the dominant limb FFM, and expressed as a percentage. Asymmetry was defined as having inter-limb leg FFM asymmetry of ±3%. Paired sample t tests were used to examine differences in dominant and non-dominant limb FFM estimates and the McNemar's test was performed to compare inter-device frequencies of asymmetry detection. An alpha level of 0.05 was utilized a priori to determine statistical significance. Results indicated that MF-BIA significantly underestimated FFM for both the dominant (mean difference = 2.00 kg; P < 0.001) and non-dominant (mean difference = 1.97 kg; P < 0.001) limbs compared to DXA. Additionally, MF-BIA detected significantly (P = 0.004) fewer cases (two) of inter-limb leg FFM asymmetry when compared to DXA (12-cases). Although MF-BIA may be a practical field assessment to track whole-body and segmental-body compositional changes over time, it may not be as sensitive as DXA to identify inter-limb leg asymmetries in career firefighters.

Monitoring menstrual health has gained popularity in sports like football as an opportunity to identify recurring symptoms or adverse symptoms related to the menstrual or hormonal contraceptive cycle; to recognize challenges related to low energy availability (LEA), low carbohydrate availability, overreaching/overtraining, and/or overall lifestyle stress due to their association with menstrual disturbance/dysfunction; to be informative in contextualizing athlete training status, e.g., training load and performance progression; and to promote and empower body/health literacy and overall health in female athletes. Monitoring menstrual health may also offer valuable insights to inform decisions regarding training and recovery. In team sports like football, where training loads and match schedules are relatively uniform across the squad, individualized strategies to effectively manage recurring adverse symptoms or menstrual disturbance/dysfunction may be necessary to ensure that all athletes can perform and recover optimally. The purpose of this article is to describe the rationale and suggested approaches for tracking menstrual and hormonal contraceptive cycles (including menstrual disturbance/dysfunction) in field settings to facilitate monitoring of menstrual health to potentially contextualize the other health and performance data. Herein, we assess the feasibility and potential limitations of different tracking methods from traditional paper and pencil records to more sophisticated digital applications and biochemical measures for use in real-world settings.

Females often experience greater weakness following immobilization compared with males. Hormonal fluctuations from the menstrual cycle or oral contraceptive (OC) use may contribute to sex differences and response variation. PURPOSE:We examined changes in peak and rapid force and surface electromyographic excitation among females using monophasic OC and females not using OC following immobilization and rehabilitation. To examine potential sex differences, a male control group was included. METHODS:Ten males, 10 OC females, and 10 non-OC females (mean ± standard deviation age = 23 ± 3 yr) immobilized their left wrist/hand with a brace for 1 wk, followed by ≥1 wk of rehabilitation. Participants completed grip tests to assess peak force and the rate of force development before and after immobilization and postrehabilitation, with electromyographic signals recorded from the extensor carpi radialis brevis and flexor digitorum superficialis. RESULTS:Grip force declined postimmobilization: males = -17.2 ± 10.3%, non-OC = -22.3 ± 24.7%, OC = -20.7 ± 14.8%. No significant time-group interactions were observed for any dependent variables ( P > 0.05, η² p ≤ 0.084). Time effects showed recovery postrehab across all groups. Rate of force development, particularly at 200 ms, declined posttest and rebounded postrehab. Extensor carpi radialis brevis excitation increased postrehab; flexor digitorum superficialis excitation responses were highly variable across participants. Five participants required >1 wk of rehabilitation (two males, two non-OC, and one OC), suggesting rapid recovery for most. CONCLUSIONS:Males and females in this study exhibited similar declines and recovery in grip force after 1 wk of wrist/hand immobilization, regardless of OC use. These findings suggest that the influence of OC use on neuromuscular outcomes in females undergoing short-term musculoskeletal rehabilitation may be minimal.

Background Creatine monohydrate (CrM) supplementation may offer unique benefits to active women through augmented cellular fluid outcomes. This study sought to evaluate the effects of CrM supplementation on whole-body 50 kHz phase angle (PhA; °) and countermovement jump height (CMJ; cm) across the menstrual cycle (MC).Methods Twenty moderately active females (mean±standard deviation: Age: 25.6±5.6 yrs; Body mass: 66.2±7.0 kg; %fat: 25.7±6.8%) were randomized to a 4×5g/day for 5 days of either CrM (n=10) or non-caloric placebo (PL; n=10), as well as randomized to MC start phase (follicular [FP] or luteal phase [LP]). PhA, measured via bioelectrical impedance analysis (Inbody 770, BioSpace, Seoul, Republic of Korea), and CMJ, evaluated using a jump mat (Just Jump Mat, Probotics Inc., Huntsville, AL), were measured at pre- and post-supplementation timepoints in the FP and LP. Acute hydration was measured prior to all testing, using urine specific gravity (USG), to ensure adequate hydration status. Repeated measures analysis of covariance tests were used to assess pre- and post-supplementation differences between groups (CrM, PL) in PhA and CMJ, covaried for USG and lean mass, respectively.Results The CrM group demonstrated significantly greater PhA at the LP post timepoint (mean difference [PL–Cr]±standard error: –0.37±0.17°; p=0.05) when compared to PL. The CrM group also demonstrated a significant change from pre to post timepoints in the FP (pre-post: -0.18±0.08°; p=0.05), while PL saw no significant change (–0.08±0.08°; p=0.35). CMJ results demonstrated a significant decrease between phases at the post timepoint for the PL group (FP–LP: 3.82±1.54 cm; p=0.02), despite no differences across time or phase in the CrM group (p>0.05).Conclusions Taken together, CrM supplementation supported improved cellular health, as indicated through raw bioimpedance measures such as PhA. Such improvements may help maintain physical performance across the MC, particularly in the mid to late LP when approaching menstruation.

CONTEXT:Understanding former professional football players' engagement with health-promoting behaviors (physical exercise, high-quality diet, and good sleep hygiene) will be helpful for developing lifestyle interventions to improve their feelings of well-being, a relatively understudied facet of health among this population. OBJECTIVE:Examine associations among health-promoting behaviors and subjective outcomes related to well-being among former National Football League (NFL) players. DESIGN:Cross-sectional. SETTING:Online or hard-copy survey. PATIENTS OR OTHER PARTICIPANTS:Former NFL players. MAIN OUTCOME MEASURE(S):Self-reported health-promoting behaviors (exercise frequency, diet quality, and sleep duration and disturbance) and factors related to well-being (Patient-Reported Outcomes Measurement Information System - Meaning and Purpose [MP], Self-Efficacy, and Ability to Participate in Social Roles and Activities [SRA]). Multivariable linear regression models were fit for each well-being-related factor with health-promoting behaviors as explanatory variables alongside select demographic, behavioral, and functional covariates. Models were fit for the full sample and separately for individual age groups: <30 years, 30 to 39 years, 40 to 49 years, 50 to 59 years, 60 to 69 years, and 70+ years. RESULTS:A total of 1784 former NFL players (aged 52.3 ± 16.3 years) completed the survey. Lower sleep disturbance was associated with better MP (β [standard error] = -0.196 [0.024]), Self-Efficacy (β [standard error] = -0.185 [0.024]), and SRA (β [standard error]= -0.137 [0.017]) in the full sample and almost all the individual age groups. More frequent moderate-to-vigorous exercise was associated with higher MP (β [standard error] = 0.068 [0.025]) and SRA (β [standard error] = 0.151 [0.065]) in the full sample and with better MP, Self-Efficacy, and SRA among select middle-aged groups (between 40 and 69 years old). Diet quality, resistance training exercise frequency, other wellness activity frequency, and sleep duration were not associated with well-being-related factors in the full group, and sparse significant associations were observed in individual age group models. CONCLUSION:Lower sleep disturbance and more frequent moderate-to-vigorous exercise frequency may be important targets for improving overall health and well-being among former NFL players.

INTRODUCTION:Short-term caloric restriction is a common practice even in lean and underweight women. We studied the impact of dietary restriction on sleep and its interplay with reproductive hormones across the menstrual cycle in women without obesity. METHODS:Seventeen healthy women without obesity, aged 23.6 ± 2.3 years (mean ± SD) underwent a neutral (± 0%) and deficient energy availability diet (-55%) in the early follicular phase of 2 menstrual cycles. Actigraphic data and urinary LH, estrone-3-glucuronide (E1G), and pregnanediol-3-glucuronide (PDG) were collected daily. Blood orexin and leptin were collected on the fifth day of each diet. Sleep was analyzed in relation to menstrual cycle phase, diet, and hormones. RESULTS:Decreased energy availability and menstrual cycle phase independently affected wake after sleep onset (WASO; P = .004, P = .007 for diet and cycle phase, respectively) and number of awakenings (NOA; P = .03, P = .0006, respectively) with the greatest sleep disruption in the late luteal phase. Sleep efficiency (SE) was lower and duration of awakenings was longer in association with dietary restriction. Orexin was positively associated with WASO (P = .02), the sleep fragmentation index (P = .001), and NOA (P = .009) and inversely related to SE (P = .02). Increasing PDG was associated with WASO (P < .05) and duration of awakenings (P < .05) and inversely associated with SE (P < .01). Increasing E1G was positively associated with WASO (P < .05) and NOA (P < .01). CONCLUSION:Short-term modest caloric restriction independently disrupts sleep and exacerbates changes in sleep that occur across the menstrual cycle in healthy, young women without obesity.

Background/Objectives: Creatine monohydrate (CrM) is considered to be one of the most effective supplements for enhancing lean body mass during resistance training. However, CrM may influence body water content, potentially confounding lean body mass measurements. Therefore, this randomised controlled trial assessed the effect of CrM alone on lean body mass following a supplement wash-in, and when combined with a resistance training program. Methods: Sixty-three (34 females, 29 males, 31 ± 8 years) participants were randomised to supplement with CrM (5 g/day for 13 weeks: wash-in + 12-week resistance training) or serve as a control (received no creatine or placebo). Lean body mass was measured using dual X-ray absorptiometry at baseline, post 7-day wash-in, and post 12 weeks of resistance training. Both groups began the same training program post CrM wash-in. Results: After the 7-day wash-in, the supplement group gained 0.51 ± 1.79 kg more lean body mass than the control group (p = 0.03). Following the wash-in, both groups gained 2 kg after resistance training (p < 0.0001), with no between-group difference in lean body mass growth (p = 0.71). Sex-disaggregated analysis showed that the supplement group, only in females, gained 0.59 ± 1.61 kg more lean body mass than the controls (p = 0.04). There were no group differences in lean body mass growth following resistance training in females (p = 0.10) or males (p = 0.35). Conclusions: A 7-day CrM wash-in increased lean body mass, particularly in females. Thereafter, CrM did not enhance lean body mass growth when combined with resistance training, likely due to its short-term effects on lean body mass measurements. A maintenance dose of higher than 5 g/day may be necessary to augment lean body mass growth.

INTRODUCTION:The menopause transition is a critical period marked by significant physiological adaptations. Data on the dynamic changes in body composition and metabolism during this transition are limited. The purpose was to determine body composition and metabolic changes over a 2-year follow-up in a cross-sectional sample of premenopausal (PRE), perimenopausal (PERI), and postmenopausal (POST) females. METHODS:Twenty-three females who previously participated in a cross-sectional study returned for a 2-year follow-up visit were classified as PRE, PERI, or POST based on menstrual history and a Menopause Health Questionnaire. Muscle size [muscle cross-sectional area (mCSA)] and muscle quality [echo intensity, (EI)] were evaluated in the vastus lateralis with ultrasound. Bone mass and body composition were assessed using dual-energy X-ray absorptiometry, and metabolic flexibility through submax exercise with indirect calorimetry. RESULTS:At the 2-year follow-up, POST females had an increase in EI (change: 26.93 ± 12.82 a.u., group×time p-adjusted = 0.001) with no change in mCSA (change: -2.03 ± 2.40 cm², group×time p = 0.980). PERI compared to PRE females had lower total bone mass (group×time p-adjusted = 0.029) with an even lower bone mass in POST compared to PERI females (group×time p-adjusted = 0.023). No differences in metabolic flexibility at any exercise intensity were observed between groups over time (group×time p = ≥ 0.05). CONCLUSION:This study highlights a decline in muscle quality and total bone mass despite stable muscle size, emphasizing the need for targeted exercise and nutrition interventions to support muscle and bone health in females around the menopause transition.

ABSTRACT:Joniak, KE, Moore, SR, Ladan, AN, Cantu, EI, Britton, ME, and Smith-Ryan, AE. Custom regional segmental lower limb lean soft tissue analysis in male and female Division I athletes. J Strength Cond Res 39(8): 868-874, 2025-Asymmetries in lean soft tissue (LST) may affect athlete availability and injury risk. Segmental custom regions of interest (C-ROI) analyses may reveal LST differences that could go undetected by whole limb analysis using dual energy x-ray absorptiometry (DXA). The purpose of the study was to describe a novel C-ROI LST segmental analysis method using DXA, and to characterize asymmetry across the sample and identify meaningful difference cut points for C-ROI segmental analyses in elite athletes. Full-body DXA testing was performed on 581 NCAA Division I athletes (46% female, mean ± SD ; Age = 20.2 ± 1.4 years, mass = 83.3 ± 26.0 kg) from August 2015 to July 2023. Custom regions of interest analyses were completed for glute, thigh, and calf segments on each leg. Regional percent differences ([segment LST difference]/[total segment LST/2] × 100) were calculated and meaningful differences were established from mean and standard deviations between limbs of each segment. The C-ROI method demonstrated high inter-reliability at each segment (intraclass correlation coefficient: 0.874-0.999). Average LST segmental limb differences for male athletes were (mean ± SD ): glute = 1.4 ± 4.4%, thigh = 0.3 ± 2.9%, calf = 0.6 ± 4.7%; and for female athletes: glute = 2.0 ± 4.4%, thigh = 0.3 ± 4.2%, calf = 0.8 ± 4.6%. Values >2 standard deviations for male athletes (glute: 10.2%, thigh: 6.1%, calf: 9.9%) and female athletes (glute: 10.9%, thigh: 8.6%, calf: 10.0%) seemed to be clinically meaningful. Using meaningful regional difference cut points may provide staff (i.e., athletic trainers, dietitians, and strength coaches) insight into acceptable LST asymmetries to better support athlete performance and return to play.

Background : Although gender parity exists at the PhD level within exercise and sport science academia, there is a lack of women in senior leadership roles. This global, mixed-methods study, conducted in 2024, aimed to (a) investigate the specific challenges women face related to family and home responsibilities and (b) examine the demographic characteristics of women working in exercise and sport science academia. Methods : As part of a larger project, participants completed an online survey and follow-up focus groups. This study specifically reports on data from 36 survey items that focused on childcare responsibilities, division of household labor, career concessions, and perceived impact of family on career progression. Focus groups provided deeper insight into these topics. Data were analyzed using descriptive statistics, group comparisons, and reflexive thematic analysis. Results : Three hundred and forty one participants completed the online survey and 37 participated across 10 focus groups. Three themes were generated from the mixed-methods data: (a) (in)visibility of women, characterized by the perceived hypervisibility of women during pregnancy and their invisibility during postpartum; (b) denial or survival of the internal pressure to manage professional and family responsibilities; (c) assumption that Woman = Mother reflecting the common social perception that all women want to be mothers, and those that do not have child caring responsibilities can be called on during nontraditional working times. Conclusion : Findings suggest that women still face family-related challenges in exercise and sport science academia that hinder their career progression.