136 research outputs found
Correction: The effect of specific bioactive collagen peptides on function and muscle remodeling during human resistance training
No full textThis article corrects the following: The effect of specific bioactive collagen peptides on function and muscle remodeling during human resistance trainingBalshaw TG, Funnell MP, McDermott E, et al. The effect of specific bioactive collagen peptides on function and muscle remodeling during human resistance training. Acta Physiol. 2023;237:e13903. doi:10.1111/apha.13903In the published article, the dietary analysis result section text and corresponding results table (Table 1) have been modified due to an error with one participant's dietary analysis data within the collagen peptide (CP) supplementation group. Mean and SD values have been updated for accuracy as have unpaired t-test p values, but this error does not alter statistical outcomes or the interpretation of the dietary analysis data, or any other data within the article. The corrected text appears below.The lead author apologizes for this error.</p
A structural study of PrCrO3 under extreme conditions: a comparison with the effects of doping
No full text24 h severe fluid restriction increases a biomarker of renal injury in healthy males
No full textPurpose: Exercise-induced hypohydration exacerbates biomarkers of renal injury, but studies isolating the effects of hypohydration without exercise have produced mixed findings. This study investigated the effects of 24-h severe fluid restriction on biomarkers of renal injury and glucose tolerance. Methods: Fifteen males (age: 27 ± 5 y; BMI: 24.1 ± 3.8 kg/m2) completed two randomised trials, involving consuming either 40 mL/kg body mass water to maintain euhydration (EU) or severe fluid restriction via limiting water consumption to 100 mL (HYP). A standardised dry food diet was consumed in both trials (~ 300 g water). At baseline and 24 h post-baseline, nude body mass, and blood and urine samples (additional urine sample at 12 h) were collected. An oral glucose tolerance test was conducted after 24-h post-baseline measurements (n = 12). Results: At 24 h, body mass loss (HYP: − 1.52 ± 0.34%, EU: − 0.24 ± 0.40%), plasma volume loss, serum, and urine osmolality were greater in HYP than EU (P ≤ 0.004). Osmolality-corrected urinary kidney injury molecule-1 (uKIM-1) concentrations were greater in HYP at 12 (HYP: 1.097 ± 0.587 ng/mOsm, EU: 0.570 ± 0.408 ng/mOsm; P < 0.001) and 24-h (HYP: 1.932 ± 1.173 ng/mOsm, EU: 1.599 ± 1.012 ng/mOsm; P = 0.01). There was no trial-by-time interactions for osmolality-corrected urinary neutrophil gelatinase-associated lipocalin concentrations (P = 0.781) or plasma glucose (P = 0.550) and insulin (P = 0.193) concentrations. Conclusion: Hypohydration produced by 24-h fluid restriction increased proximal tubular injury but did not affect glucose tolerance
Blinded and unblinded hypohydration similarly impair cycling time trial performance in the heat in trained cyclists
No full textKnowledge of hydration status may contribute to hypohydration-induced exercise performance decrements, therefore, this study compared blinded and unblinded hypohydration on cycling performance. Fourteen trained, non-heat acclimated cyclists (age 25 ± 5 y; V̇O2peak 63.3 ± 4.7 mL∙kg-1∙min-1; cycling experience 6 ± 3 y) were pair-matched to blinded (B) or unblinded (UB) groups. After familiarisation, subjects completed euhydrated (B-EUH; UB-EUH) and hypohydrated (B-HYP; UB-HYP) trials in the heat (31˚C); 120 min cycling preload (50% Wpeak) and a time trial (~15 min). During the preload of all trials, 0.2 mL water∙kg body mass-1 was ingested every 10 min, with additional water provided during EUH trials to match sweat losses. To blind the B group, a nasogastric tube was inserted in both trials and used to provide water in B-EUH. The preload induced similar ( P=0.895) changes in body mass between groups (B-EUH -0.6 ± 0.5%; B-HYP -3.0 ± 0.5%; UB-EUH -0.5 ± 0.3%; UB-HYP -3.0 ± 0.3%). All variables responded similarly between B and UB groups ( P≥0.558), except thirst ( P=0.004). Changes typical of hypohydration (increased heart rate, RPE, gastrointestinal temperature, serum osmolality and thirst, decreased plasma volume; P≤0.017) were apparent in HYP by 120 min. Time trial performance was similar between groups ( P=0.710) and slower ( P≤0.013) with HYP for B (B-EUH 903 ± 89 s; B-HYP 1008 ± 121 s; -11.4%) and UB (UB-EUH 874 ± 108 s; UB-HYP 967 ± 170 s; -10.1%). Hypohydration of ~3% body mass impairs time trial performance in the heat, regardless of knowledge of hydration status
Blinded and unblinded hypohydration similarly impair cycling time trial performance in the heat in trained cyclists
No full textKnowledge of hydration status may contribute to hypohydration-induced exercise performance decrements, therefore, this study compared blinded and unblinded hypohydration on cycling performance. Fourteen trained, non-heat acclimated cyclists (age 25 ± 5 y; V̇O2peak 63.3 ± 4.7 mL∙kg-1∙min-1; cycling experience 6 ± 3 y) were pair-matched to blinded (B) or unblinded (UB) groups. After familiarisation, subjects completed euhydrated (B-EUH; UB-EUH) and hypohydrated (B-HYP; UB-HYP) trials in the heat (31˚C); 120 min cycling preload (50% Wpeak) and a time trial (~15 min). During the preload of all trials, 0.2 mL water∙kg body mass-1 was ingested every 10 min, with additional water provided during EUH trials to match sweat losses. To blind the B group, a nasogastric tube was inserted in both trials and used to provide water in B-EUH. The preload induced similar ( P=0.895) changes in body mass between groups (B-EUH -0.6 ± 0.5%; B-HYP -3.0 ± 0.5%; UB-EUH -0.5 ± 0.3%; UB-HYP -3.0 ± 0.3%). All variables responded similarly between B and UB groups ( P≥0.558), except thirst ( P=0.004). Changes typical of hypohydration (increased heart rate, RPE, gastrointestinal temperature, serum osmolality and thirst, decreased plasma volume; P≤0.017) were apparent in HYP by 120 min. Time trial performance was similar between groups ( P=0.710) and slower ( P≤0.013) with HYP for B (B-EUH 903 ± 89 s; B-HYP 1008 ± 121 s; -11.4%) and UB (UB-EUH 874 ± 108 s; UB-HYP 967 ± 170 s; -10.1%). Hypohydration of ~3% body mass impairs time trial performance in the heat, regardless of knowledge of hydration status
A self-paced 15-minute cycling time trial is a reliable performance measure in recreationally active individuals
No full textCycling time trial (TT) protocols have been shown to be reliable in trained cyclists, but their reproducibility in lesser-trained individuals is unknown. This study examined the reliability of a self-paced 15-minute cycling TT in recreationally active individuals. Twelve recreationally active males (age 27 ± 3 y; body mass 75.2 ± 8.9 kg; (Formula presented.) O2peak = 51.10 ± 7.53 ml∙kg∙min−1) completed a VO2peak test and four experimental trials, separated by > 48 h. Experimental trials consisted of 10 min cycling at 60% Wmax, followed by a self-paced 15-min TT. Heart rate and work done were recorded every 5 min during the TT; and coefficient of variation (CV) was calculated. Work done was not different (P = 0.706) between trials (193.2 ± 45.3 kJ; 193.2 ± 43.5 kJ; 192.0 ± 42.3 kJ; 193.9 ± 42.8 kJ). Within participant CV ranged from 0.5–4.9% for the four TTs, with a mean CV of 2.1%. Mean CV decreased from 2.0% (range 0.1–5.0%) for the first two TTs to 1.7% (range 0.2–5.6%) for the second and third TTs, and further decreased to 1.0% (range 0.2–1.8%) for the third and fourth TTs. In conclusion, the use of a short-duration self-paced cycling TT in recreationally active individuals is a reliable performance measure.</p
An afternoon snack of berries reduces subsequent energy intake compared to an isoenergetic confectionary snack
No full textObservational studies suggest that increased fruit and vegetable consumption can contribute to weight maintenance and facilitate weight loss when substituted for other energy dense foods. Therefore, the purpose of the present study was to assess the effect of berries on acute appetite and energy intake. Twelve unrestrained pre-menopausal women (age 21±2y; BMI 26.6±2.6kgm-2; body fat 23±3%) completed a familiarisation trial and two randomised experimental trials. Subjects arrived in the evening (~5pm) and consumed an isoenergetic snack (65kcal) of mixed berries (BERRY) or confectionary sweets (CONF). Sixty min later, subjects consumed a homogenous pasta test meal until voluntary satiation, and energy intake was quantified. Subjective appetite (hunger, fullness, desire to eat and prospective food consumption) was assessed throughout trials, and for 120min after the test meal. Energy intake was less (P0.095) or interaction (P>0.351) effects for any subjective appetite ratings. Time taken to eat the BERRY snack (4.05±1.12min) was greater (P<0.001) than the CONF snack 0.93±0.33min). This study demonstrates that substituting an afternoon confectionary snack with mixed berries decreased subsequent energy intake at dinner, but did not affect subjective appetite. This dietary strategy could represent a simple method for reducing daily energy intake and aiding weight management
Counteracting the Inactivity Epidemic:Should We Ring-Fence Paid Work Time for Physical Activity?
No full textEcologically Valid Carbohydrate Intake during Soccer-Specific Exercise Does Not Affect Running Performance in a Fed State.
No full textThis study assessed the effect of carbohydrate intake on self-selected soccer-specific running performance. Sixteen male soccer players (age 23 ± 4 years; body mass 76.9 ± 7.2 kg; predicted VO2max = 54.2 ± 2.9 mL∙kg-1∙min-1; soccer experience 13 ± 4 years) completed a progressive multistage fitness test, familiarisation trial and two experimental trials, involving a modified version of the Loughborough Intermittent Shuttle Test (LIST) to simulate a soccer match in a fed state. Subjects completed six 15 min blocks (two halves of 45 min) of intermittent shuttle running, with a 15-min half-time. Blocks 3 and 6, allowed self-selection of running speeds and sprint times, were assessed throughout. Subjects consumed 250 mL of either a 12% carbohydrate solution (CHO) or a non-caloric taste matched placebo (PLA) before and at half-time of the LIST. Sprint times were not different between trials (CHO 2.71 ± 0.15 s, PLA 2.70 ± 0.14 s; p = 0.202). Total distance covered in self-selected blocks (block 3: CHO 2.07 ± 0.06 km; PLA 2.09 ± 0.08 km; block 6: CHO 2.04 ± 0.09 km; PLA 2.06 ± 0.08 km; p = 0.122) was not different between trials. There was no difference between trials for distance covered (p ≥ 0.297) or mean speed (p ≥ 0.172) for jogging or cruising. Blood glucose concentration was greater (p < 0.001) at the end of half-time during the CHO trial. In conclusion, consumption of 250 mL of 12% CHO solution before and at half-time of a simulated soccer match does not affect self-selected running or sprint performance in a fed state
Chronic ingestion of a low dose of caffeine induces tolerance to the performance benefits of caffeine
No full textThis study examined effects of 4 weeks of caffeine supplementation on endurance performance. Eighteen low-habitual caffeine consumers ( 0.05). Before supplementation, all participants completed one V̇O2peak test, one practice trial and 2 experimental trials (acute 3 mg · kg−1 caffeine [precaf] and placebo [testpla]). During the supplementation period a second V̇O2peak test was completed on day 21 before a final, acute 3 mg · kg−1 caffeine trial (postcaf) on day 29. Trials consisted of 60 min cycle exercise at 60% V̇O2peak followed by a 30 min performance task. All participants produced more external work during the precaf trial than testpla, with increases in the caffeine (383.3 ± 75 kJ vs. 344.9 ± 80.3 kJ; Cohen’s d effect size [ES] = 0.49; P = 0.001) and placebo (354.5 ± 55.2 kJ vs. 333.1 ± 56.4 kJ; ES = 0.38; P = 0.004) supplementation group, respectively. This performance benefit was no longer apparent after 4 weeks of caffeine supplementation (precaf: 383.3 ± 75.0 kJ vs. postcaf: 358.0 ± 89.8 kJ; ES = 0.31; P = 0.025), but was retained in the placebo group (precaf: 354.5 ± 55.2 kJ vs. postcaf: 351.8 ± 49.4 kJ; ES = 0.05; P > 0.05). Circulating caffeine, hormonal concentrations and substrate oxidation did not differ between groups (all P > 0.05). Chronic ingestion of a low dose of caffeine develops tolerance in low-caffeine consumers. Therefore, individuals with low-habitual intakes should refrain from chronic caffeine supplementation to maximise performance benefits from acute caffeine ingestion
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