New Zealand black currant extract (NZBC) has been shown to increase fat oxidation during exercise and decrease the postexercise blood pressure in men and women. The change in fat oxidation by NZBC has also been shown to be correlated to body composition in men and women. There has never been a comparison of sex responses within the same study. Twenty-two participants (11 men and 11 women, age: 29 ± 8 years, maximal oxygen uptake: 44 ± 9 ml·kg-1·min-1, body fat: 18% ± 6%) had resting blood pressure measured for 2 hr (no exercise). In a double-blind, placebo-controlled (PLA), randomized crossover design, participants completed 1 hr of treadmill exercise at 50% maximal oxygen uptake with expired gas measurement, followed by 2-hr resting blood pressure measurement with 7 days of NZBC or PLA. Average fat oxidation was different between the conditions (NZBC: 0.27 ± 0.11 g/min, PLA: 0.21 ± 0.12 g/min, p < .001), but the response between men and women was not different. When combined, there was no relationship (p > .05) between body fat percentage and change in fat oxidation (r = -.079), with men also demonstrating no relationship (r = -.069), although women did demonstrate a relationship (r = .691, p < .05). In the 2-hr rest, systolic pressure delta change was larger with NZBC than PLA (no exercise vs. NZBC: -5.5 ± 5.4 mmHg vs. no exercise vs. PLA: -2.9 ± 5.1 mmHg, p < .001) but was not different between men and women. A 7-day intake of NZBC extract increases fat oxidation during moderate-intensity exercise and decreases postexercise blood pressure in men and women. The magnitude of change in fat oxidation in women is correlated to body fat percentage.
Athletes and physically active individuals consume sport nutrition supplements to enhance competitive sport performance and exercise recovery. Polyphenols have emerged as a promising area of research with application for sport and exercise nutrition owing to affecting physiologic mechanisms for exercise performance and recovery. The anthocyanin is a polyphenol that can be abundantly present in dark-colored fruits, berries, and vegetables. Anthocyanins and anthocyanin-induced metabolites will provide antioxidant and anti-inflammatory effects. The focus of this narrative review was on the observations with intake of anthocyanin-rich blackcurrant supplements on whole-body exercise performance and exercise recovery. This review included 17 studies with a randomized placebo-controlled crossover design (10 studies on performance and 8 on recovery effects) and 1 with a randomized placebo-controlled parallel group design (recovery effects). Among the performance studies, 6 studies (60%) reported positive effects, 3 studies (30%) reported no significant effects, and 1 study (10%) reported a mixed outcome. Among the recovery studies, 7 studies (78%) reported positive effects, 1 study (11%) reported no significant effects, and 1 study (11%) reported a negative effect. Studies with intake of supplements made from New Zealand blackcurrants (dose: 1.8-3.2 mg/kg and 105-315 mg anthocyanins, acute to 7-d intake) provided meaningful (but not always consistent) effects on continuous and intermittent exercise performance tasks (i.e. rowing, cycling, and running) and markers for exercise recovery. A mechanistic understanding for the beneficial exercise effects of anthocyanins for athletes and physically active individuals is still limited. Future work requires a better understanding of the specific types of anthocyanins and anthocyanin-induced metabolites and their effects on altering cell function that can enhance exercise performance and recovery.
Seven-day intake of anthocyanins from New Zealand blackcurrant (NZBC) extract increased cardiac output and femoral artery diameter during a sustained submaximal isometric contraction. It is not known if there are intake duration effects by NZBC extract on the isometric contraction-induced cardiovascular responses. In a repeated measures design, male participants (n = 19, age: 26 +/- 4 years) performed a 120-second submaximal (30%) isometric contraction of the knee extensors at baseline and following 1, 4 and 7-days intake of 600 mg center dot day(-1) NZBC extract. During the 120-second submaximal isometric contraction, femoral artery diameter and cardiovascular responses were measured with ultrasound and beat-to-beat hemodynamic monitoring. Femoral artery was larger following 4-days (mean difference = 0.046 cm, 95% CI [0.012, 0.080], p = 0.005) and 7-days (mean difference = 0.078 cm, 95% CI [0.034, 0.123], p < 0.001) in comparison to baseline with no increase with 1-day intake. Systolic and diastolic blood pressure, heart rate and total peripheral resistance were not changed by NZBC extract at 1, 4 and 7-days intake. However, mean arterial pressure, stroke volume, cardiac output and total peripheral resistance were changed at time points during the isometric contraction following 7-days intake in comparison to 1-day intake of NZBC extract (p < 0.05). Alterations in femoral artery diameter and some cardiovascular responses during a submaximal sustained isometric contraction of the knee extensors are affected by the intake duration of New Zealand blackcurrant extract, with no effects by 1-day intake. Our observations suggest that the bioavailability of blackcurrant anthocyanins and anthocyanin-derived metabolites is required for days to alter the mechanisms for isometric-contraction induced cardiovascular responses.
The aim of this study was to systematically review the evidence on the outcomes of using different intensities of static stretching on range of motion (ROM) and strength. PubMed, Web of Science and Cochrane controlled trials databases were searched between October 2021 and February 2022 for studies that examined the effects of different static stretching intensities on range of motion and strength. Out of 6285 identified records, 18 studies were included in the review. Sixteen studies examined outcomes on ROM and four on strength (two studies included outcomes on both ROM and strength). All studies demonstrated that static stretching increased ROM; however, eight studies demonstrated that higher static stretching intensities led to larger increases in ROM. Two of the four studies demonstrated that strength decreased more following higher intensity stretching versus lower intensity stretching. It appears that higher intensity static stretching above the point of discomfort and pain may lead to greater increases in ROM, but further research is needed to confirm this. It is unclear if high-intensity static stretching leads to a larger acute decrease in strength than lower intensity static stretching.
Previous observations demonstrate New Zealand blackcurrant (NZBC) extract to alter cardiovascular responses at rest without prior exercise. However, the prolonged effects of NZBC on blood pressure and heart rate variability following exercise are not known. Participants (n15 [five women], age: 31 ± 9 years, maximal oxygen uptake: 44 ± 9 ml·kg-1·min-1) undertook a control condition of 2 hr of lying supine rest. Subsequently, in a double-blind, placebo (PLA)-controlled, randomized crossover design participants completed 1 hr of treadmill exercise at 50% maximal oxygen uptake followed by 2-hr supine rest with blood pressure and heart rate variability measurement following a 7-day intake of NZBC and PLA. With NZBC, there was an increase in average fat oxidation (NZBC: 0.24 ± 0.11 vs. PLA: 0.17 ± 0.11 g/min, p = .005), and larger high-frequency relative power during the exercise (p = .037). In the 2-hr rest period, delta change for systolic pressure was larger with NZBC than PLA (Control vs. NZBC: -5.6 ± 6.4, Control vs. PLA: -3.5 ± 6.0 mmHg, p = .033) but was not different for diastolic or mean arterial pressure. There were no alterations in heart rate variabilities during the 2 hr following the exercise with NZBC. A 7-day intake of NZBC causes a larger postexercise hypotension response in young, physically active men and women following 1 hr of treadmill exercise at 50% maximal oxygen uptake.
Intake of anthocyanin-rich New Zealand blackcurrant (NZBC) can alter physiological responses that enhance exercise performance. In two studies, we examined the effects of NZBC extract on force steadiness during a sustained submaximal isometric contraction of the quadriceps femoris muscle. With repeated measures designs, male participants in study one (n = 13) and study two (n = 19) performed a 120 s submaximal (30%) isometric contraction of the quadriceps femoris muscle following a 7-day intake of NZBC extract and placebo (study one) and following 0 (control), 1-, 4- and 7-day intake of NZBC extract (study two). Participants for both studies were different. In study one, NZBC extract enhanced isometric force steadiness during the 120 s contraction (placebo: 6.58 ± 2.24%, NZBC extract: 6.05 ± 2.24%, p = 0.003), with differences in the third (60–89 s) and fourth quartile (90–120 s) of the contraction. In study two, isometric force steadiness was not changed following 1 and 4 days but was enhanced following 7-day intake of NZBC extract in comparison to control. In study two, the enhanced isometric force steadiness following 7-day intake did occur in the second (30–59 s), third (60–89 s) and fourth (90–120 s) quartiles. Daily supplementation of anthocyanin-rich NZBC extract can enhance force steadiness of the quadriceps femoris muscle during a sustained submaximal isometric contraction. Our observations may have implications for human tasks that require postural stability.
Skin volatile organic compounds (VOCs) can cause body odor or reveal human disease and may result from lipid peroxidation or activity by skin bacteria. We examined the effect of intake of New Zealand blackcurrant (NZBC) powder for 77 skin VOCs in middle-aged and older adults in a crossover design. Fourteen adults (nine males, age: 55 ± 5 yrs) consumed NZBC powder for 7 days (6 g·day-1 with 138.6 mg anthocyanins). Two hours after the last intake, a passive flux sampler with trapping media was applied in the base of the neck for 1 hour. Gas chromatography-mass spectrometry was used for media analysis. Habitual anthocyanin intake was quantified using a food frequency questionnaire. Compared to control (i.e., no intake of NZBC powder), emission of six skin VOCs (i.e., 2-nonenal, acetic acid, 2-hexanone, 6-methyl-5-hepten-2-one, benzaldehyde, allyl methyl sulfide) were lower by more than 25%. Increases were observed for γ-octanolactone (+184%) and γ-decanolactone (+89%). A trend for a decrease for isovaleraldehyde, hexanal, and 2-pentanone, and an increase for heptanoic acid and γ-nonanolactone was observed. There was a significant correlation with daily habitual dietary anthocyanin intake for control values of hexanal and percentage change of γ-octanolactone. NZBC powder can change emanation of some VOCs in human skin. Analysis of skin VOCs following specific polyphenol intake may address the impact of dietary components to affect internal metabolic processes, body odor, and health.
New Zealand blackcurrant (NZBC) can increase exercise performance in young adults, potentially by anthocyanin-induced cardiovascular function alterations and increased blood flow, however, effects upon blood pressure, functional exercise performance and cognitive function in older adults is unknown. In a randomized, double-blind, placebo-controlled, cross-over design, 14 older adults (age: 69 ± 4 years, height: 172 ± 9 cm, body mass: 85 ± 12) ingested NZBC extract (600 mg·day-1 CurraNZ™) or placebo (PL, 600 mg microcrystalline cellulose) for 7-days (7-day washout between conditions). On day-7, 2-hours following consumption of the capsules, resting blood pressure, cognitive function (Cambridge neuropsychological test automated battery) and 6-minute walk test performance and were measured. Intake of NZBC caused a decrease (p < 0.05) in systolic (PL: 136 ± 14; NZBC: 130 ± 12 mmHg) and diastolic (PL: 84 ± 11; NZBC 78 ± 6 mmHg) blood pressure. There was no effect on 6-minute walk performance or cognitive function variables. Future research should address optimization of intake and examine cardiovascular responses during exercise.
Sujon Berries (Nelson, NZ) provided supplements. Support for conference attendance was obtained from Blackcurrant New Zealand Inc. (NZ).
Foods and supplements high in anthocyanins are gaining popularity within sports nutrition. Anthocyanins are pigments within berries and other colorful fruits and vegetables. They have antioxidative and anti-inflammatory actions that improve recovery from exercise. Furthermore, anthocyanins can also affect vasoactive properties, including decreasing mean arterial blood pressure and increasing vasodilation during exercise. In vitro observations have shown anthocyanin- and metabolite-induced activation of endothelial nitric oxide synthase and human vascular cell migration. However, effects of anthocyanins on exercise performance without a prior muscle-damaging or metabolically demanding bout of exercise are less clear. For example, exercise performance effects have been observed for blackcurrant but are less apparent for cherry, therefore indicating that the benefits could be due to the specific source-dependent anthocyanins. The mechanisms by which anthocyanin intake can enhance exercise performance may include effects on blood flow, metabolic pathways, and peripheral muscle fatigue, or a combination of all three. This narrative review focuses on the experimental evidence for anthocyanins to improve exercise performance in humans.
Magnesium supplementation modulates glucose metabolism and inflammation, which could influence exercise performance and recovery. This study investigated the effect of magnesium intake on physiological responses and performance during eccentric exercise and recovery. Nine male recreational runners completed a counterbalanced, double-blind, placebo-controlled, cross-over study, registered at ClinicalTrial.gov. Participants consumed low magnesium diets and were supplemented with 500 mg/day of magnesium (SUP) or placebo (CON) for 7 days prior to a 10 km downhill (− 10%) running time trial (TT), separated by a 2-week washout period. At baseline and 24 h post-TT, maximal muscle force was measured. Interleukin-6 (IL-6), soluble interleukin-6 receptor (sIL-6R) and creatine kinase (CK) were measured at rest, 0 h, 1 h and 24 h post-TT. Muscle soreness was measured at the previous times plus 48 h and 72 h post. Glucose and lactate were measured during the TT. The main effect of condition was detected for IL-6 (SUP: 1.36 ± 0.66 vs CON: 2.06 ± 1.14 pg/ml) (P < 0.05, η2 = 0.54), sIL-6R (SUP: 27,615 ± 8446 vs CON: 24,368 ± 7806 pg/ml) (P < 0.05, η2 = 0.41) and muscle soreness (P < 0.01, η2 = 0.67). Recovery of blood glucose and muscle soreness were enhanced in SUP post-TT. There were no differences in glucose and lactate during the TT, or post measures of CK and maximal muscle force. Magnesium supplementation reduced the IL-6 response, enhanced recovery of blood glucose, and muscle soreness after strenuous exercise, but did not improve performance or functional measures of recovery.
New Zealand blackcurrant (NZBC) extract enhanced exercise-induced fat oxidation and 16.1 km cycling time trial (TT) in normobaric normoxia. The effect of NZBC extract on physiological and metabolic responses was examined during steady state cycling and a 16.1 km TT in normobaric hypoxia. This study used a randomized, double-blind, crossover design. Eleven healthy male cyclists (age: 38 ± 11 y, height: 179 ± 4 cm, body mass: 76 ± 8 kg, V ˙ O2max: 47 ± 5 mL·kg−1·min−1, mean ± SD) ingested NZBC extract (600 mg·day−1 CurraNZ® containing 210 mg anthocyanins) or a placebo (600 mg microcrystalline cellulose M102) for seven days (washout 14 days) and performed a steady state cycling test (3 × 10 min at 45%, 55% and 65% V ˙ O2max) followed by a 16.1 km TT at a simulated altitude of ~2500 meters (~15% of O2). Indirect calorimetry was used to measure substrate oxidation during steady state cycling. Intake of NZBC extract had no effect on blood glucose and lactate, heart rate, substrate oxidation, and respiratory exchange ratio during steady state cycling at 45%, 55% and 65% V ˙ O2max, and on 16.1 km TT performance (placebo: 1685 ± 92 s, NZBC extract: 1685 ± 99 s, P = 0.97). Seven days intake of New Zealand blackcurrant extract does not change exercise-induced metabolic responses and 16.1 km cycling time trial performance for moderately endurance-trained men in normobaric hypoxia.
Intake of the catechin epigallocatechin gallate and caffeine has been shown to enhance exercise-induced fat oxidation. Matcha green tea powder contains catechins and caffeine and is consumed as a drink. We examined the effect of Matcha green tea drinks on metabolic, physiological, and perceived intensity responses during brisk walking. A total of 13 females (age: 27 ± 8 years, body mass: 65 ± 7 kg, height: 166 ± 6 cm) volunteered to participate in the study. Resting metabolic equivalent (1-MET) was measured using Douglas bags (1-MET: 3.4 ± 0.3 ml·kg-1·min-1). Participants completed an incremental walking protocol to establish the relationship between walking speed and oxygen uptake and individualize the walking speed at 5- or 6-MET. A randomized, crossover design was used with participants tested between Days 9 and 11 of the menstrual cycle (follicular phase). Participants consumed three drinks (each drink made with 1 g of Matcha premium grade; OMGTea Ltd., Brighton, UK) the day before and one drink 2 hr before the 30-min walk at 5- (n = 10) or 6-MET (walking speed: 5.8 ± 0.4 km/hr) with responses measured at 8-10, 18-20, and 28-30 min. Matcha had no effect on physiological and perceived intensity responses. Matcha resulted in lower respiratory exchange ratio (control: 0.84 ± 0.04; Matcha: 0.82 ± 0.04; p < .01) and enhanced fat oxidation during a 30-min brisk walk (control: 0.31 ± 0.10; Matcha: 0.35 ± 0.11 g/min; p < .01). Matcha green tea drinking can enhance exercise-induced fat oxidation in females. However, when regular brisk walking with 30-min bouts is being undertaken as part of a weight loss program, the metabolic effects of Matcha should not be overstated.
Objectives. - Futsal game requires players to perform frequent bouts of high-intensity activity with limited rest periods that are not sufficient for full recovery. Therefore, creatine supplementation may enhance performance by improving recovery rate. Along with this, the number of studies conducted to determine the effects of creatine on performance in the females is scarce. Thus, the main aim of this study is to identify the effects of short-term (7/day) creatine supplementation on leg strength, velocity and agility in young female futsal players. Equipment and methods. - A total of thirty of young female futsal players (aged: 19.83 +/- 1.13 years) participated in the study which was designed as randomized and double-blind, on a voluntary basis. Participants were randomly assigned either to creatine (n=15) or placebo (n = 15) group. Over 7 days, creatine group received 0.25 g/kg/day micronized pure creatine mono hydrate (Creapure, Hardline Nutrition, Kavi Gida Istanbul, Turkey) and placebo group did not take any supplements, apart from maltodextrin (Fantomalt, Nutricia, United Kingdom). Before and after 7 days of loading creatine supplementation, body weight, leg strength, velocity and agility performance of the participants were determined. The data obtained were analysed with ANCOVA statistical model. Results. - Creatine supplementation significantly improved 10 m, 20 m and 30 m speed performances (P < 0.05), leg strength (P<0.05) and agility (P < 0.05) in female futsal players. Depending on the creatine loading, however, no significant change in body weight was observed (P > 0.05). The data obtained provide that 7 days low dose creatine supplementation may be an effective approach for improving exercise capacity in female futsal players without an associated increase in body weight. (C) 2018 Elsevier Masson SAS. All rights reserved.
It has been previously shown that New Zealand blackcurrant (NZBC) extract increased fat oxidation during short duration cycling. The present study examined the effect of different doses of NZBC extract on substrate oxidation and physiological responses during prolonged cycling.
Blackcurrant contains anthocyanins that could alter cardiovascular function and reduce cardiovascular disease risk. We examined dose responses of New Zealand blackcurrant (NZBC) extract on cardiovascular function during supine rest.
Blackcurrant is rich in anthocyanins that may affect exercise-induced physiological responses. We examined tissue oxygen saturation, muscle activity, cardiovascular responses and femoral artery diameter during a submaximal sustained isometric contraction. In a randomised, double-blind, crossover design, healthy men (n = 13, age: 25 ± 4 years, BMI: 25 ± 3 kg·m−2, mean ± SD) ingested New Zealand blackcurrant (NZBC) extract (600 mg∙day−1 CurraNZ™) or placebo (PL) for 7-days separated by 14-days washout. Participants produced isometric maximal voluntary contractions (iMVC) and a 120-s 30%iMVC of the quadriceps with electromyography (EMG), near-infrared spectroscopy, hemodynamic and ultrasound recordings. There was no effect of NZBC extract on iMVC (NZBC: 654 ± 73, PL: 650 ± 78 N). During the 30%iMVC with NZBC extract, total peripheral resistance, systolic, diastolic, and mean arterial pressure were lower with increased cardiac output and stroke volume. With NZBC extract, EMG root mean square of the vastus medialis and muscle oxygen saturation were lower with higher total haemoglobin. During the 30%iMVC, femoral artery diameter was increased with NZBC extract at 30 (6.9%), 60 (8.2%), 90 (7.7%) and 120 s (6.0%). Intake of NZBC extract for 7-days altered cardiovascular responses, muscle oxygen saturation, muscle activity and femoral artery diameter during a 120-s 30%iMVC of the quadriceps. The present study provides insight into the potential mechanisms for enhanced exercise performance with intake of blackcurrant.
It was observed previously that New Zealand blackcurrant (NZBC) extract reduced slowing of the maximal 15 m sprint speed during the Loughborough Intermittent Shuttle Test. We examined the effect of NZBC extract on the performance of the Running Based Anaerobic Sprint Test (RAST, 6 × 35-m sprints with 10 seconds passive recovery) in trained youth and recreationally active football players. Fifteen recreationally active (University team) (age: 20 ± 1 years, height: 174 ± 19 cm, body mass: 80 ± 13 kg) and nine trained youth players (English professional club) (age: 17 ± 0 years, height: 178 ± 8 cm, body mass: 69 ± 9 kg, mean ± SD) participated in three testing sessions. Prior to the RASTs, participants consumed two capsules of NZBC extract (600 mg∙day−1 CurraNZ®) or placebo (P) for 7 days (double blind, randomised, cross-over design, wash-out at least 14 days). Ability difference between groups was shown by sprint 1 time. In the placebo condition, trained youth players had faster times for sprint 1 (5.00 ± 0.05 s) than recreationally active players (5.42 ± 0.08 s) (p < 0.01). In trained youth players, there was a trend for an effect of NZBC extract (p = 0.10) on the slowing of the sprint 1 time. NZBC extract reduced slowing of the sprint 5 time (P: 0.56 ± 0.22 s; NZBC: 0.35 ± 0.25, p = 0.02) and this was not observed in recreationally active players (P: 0.57 ± 0.48 s; NZBC: 0.56 ± 0.33, p = 0.90). For fatigue index, expressed as a % change in fastest sprint time, there was a strong trend to be lower in both trained youth and recreationally active players combined by NZBC extract (P: −13 ± 7%; NZBC: −11 ± 6%, p = 0.06) with 12 participants (five trained youth) experiencing less fatigue. New Zealand blackcurrant extract seems to benefit repeated sprint performance only in trained football players.
Background: Blood glucose and insulin are elevated after intake of carbohydrate, with levels returning to normal in about 2-3 hours after ingestion. We examined the effects of daily New Zealand blackcurrant intake over 7 days on fasting glucose and insulin levels and the responses of glucose and insulin during an oral glucose tolerance test (i.e. OGTT).Methods: Seventeen healthy participants (9 males, 8 females, age: 24±8 years, body mass: 75.4±16.4 kg, height 172±11 cm, body mass index: 25.3±3.3) consumed 6 g·day-1 New Zealand blackcurrant (NZBC) powder for 7 days. Every 6 g of the serving contained 138.6 mg anthocyanins, 49 mg vitamin C, and 5.2 g of carbohydrates with total phenolic content 271.6 mg. A cross-over design was used. Participants completed one OGTT before starting the supplementation (day 0) and another OGTT after 7 days of the supplementation (day 7). For the OGTT, participants were seated and consumed 75 g of glucose dissolved in 250 mL water. Finger prick capillary samples were taken before and every 30 minutes for a total of 120 minutes after consuming the glucose drink. Following duplicate glucose analysis, blood samples were centrifuged and then plasma was separated and frozen (-20°C) for triplicate insulin analysis using a human 96-well insulin enzyme-linked immunosorbent assay (IBL international, Hamburg, Germany).Results: NZBC had no effect on fasting glucose (control: 4.46±0.45; NZBC: 4.41±0.44 mmol·L1, P=0.657), although there was a trend for fasting insulin to be 14.3% lower (control: 66.5±28.2; NZBC: 57.0±29.5 pmol·L-1) (P=0.091). HOMA-IR was not different between the control and NZBC (1.81±0.73 vs 1.58±0.83) (P=0.126). With NZBC during the OGTT, plasma glucose at 60 min was 8.1% lower (control: 6.68±1.13; NZBC: 6.14±1.41 mmol·L-1; P=0.016), insulin at 30 min was 18.4% lower (control: 337.1±228.3; NZBC: 275.0±136.4 pmol·L-1; P= 0.021), and insulin at 60 min was 39.2% lower (control: 297.8±154.3; NZBC: 181.2±97.4 pmol·L-1; P= 0.002). With NZBC during the OGTTs, areas-under-the-curve for plasma glucose (control: 752.6±79.4, NZBC: 709.8±93.3 mmol·L-1·120 min) and insulin (control: 28443±12816, NZBC: 20406±7985, pmol·L-1·120 min) were 5.7% (P=0.051) and 31.1% lower (P<0.001) respectively. Conclusion: A trend for lower fasting insulin with normal glucose and lower areas under the curve for glucose and insulin suggests that repeated intake of New Zealand blackcurrant powder increases insulin sensitivity. This is the first observation of a high-anthocyanin containing berry powder to increase insulin sensitivity. Regular intake of New Zealand blackcurrant powder may be beneficial for the postprandial responses in people with type 2 diabetes or metabolic syndrome.Keywords: Anthocyanins, Glycaemia, Insulinaemia, Berries, Blood Glucose, Diabetes, Metabolic Syndrome