Int J Sport Nutr Exerc Metab [JOURNAL]
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200 papers
Protein Intake Distribution: Beneficial, Detrimental, or Inconsequential for Muscle Anabolism? Response to Witard & Mettler.
Trommelen J, Holwerda AM, van Loon LJC
Int J Sport Nutr Exerc Metab · 2024 Sep · PMID 38986499 · Publisher ↗
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An Opinion on the Interpretation of Bone Turnover Markers Following Acute Exercise or Nutrition Intervention and Considerations for Applied Research.
Hutson MJ, Varley I
Int J Sport Nutr Exerc Metab · 2024 Sep · PMID 38925537 · Publisher ↗
It is important for athlete and public health that we continue to develop our understanding of the effects of exercise and nutrition on bone health. Bone turnover markers (BTMs) offer an opportunity to accelerate the pro...
It is important for athlete and public health that we continue to develop our understanding of the effects of exercise and nutrition on bone health. Bone turnover markers (BTMs) offer an opportunity to accelerate the progression of bone research by revealing a bone response to exercise and nutrition stimuli far more rapidly than current bone imaging techniques. However, the association between short-term change in the concentration of BTMs and long-term bone health remains ambiguous. Several other limitations also complicate the translation of acute BTM data to applied practice. Importantly, several incongruencies exist between the effects of exercise and nutrition stimuli on short-term change in BTM concentration compared with long-term bone structural outcomes to similar stimuli. There are many potential explanations for these inconsistencies, including that short-term study designs fail to encompass a full remodeling cycle. The current article presents the opinion that data from relatively acute studies measuring BTMs may not be able to reliably inform applied practice aiming to optimize bone health. There are important factors to consider when interpreting or translating BTM data and these are discussed.
Caffeine Gum Improves Reaction Time but Reduces Composure Versus Placebo During the Extra-Time Period of Simulated Soccer Match-Play in Male Semiprofessional Players.
Field A, Corr L, Birdsey L … +12 more , Langley C, Marshall B, Wood G, Hearris M, Martinho D, Carbry C, Naughton R, Fleming J, Mohr M, Krustrup P, Russell M, David Harper L
Int J Sport Nutr Exerc Metab · 2024 Sep · PMID 38917989 · Publisher ↗
This study aimed to determine whether caffeine gum influenced perceptual-cognitive and physical performance during the extra-time period of simulated soccer match-play. Semiprofessional male soccer players (n = 12, age:...
This study aimed to determine whether caffeine gum influenced perceptual-cognitive and physical performance during the extra-time period of simulated soccer match-play. Semiprofessional male soccer players (n = 12, age: 22 ± 3 years, stature: 1.78 ± 0.06 m, mass: 75 ± 9 kg) performed 120-min soccer-specific exercise on two occasions. In a triple-blind, randomized, crossover design, players chewed caffeinated (200 mg; caffeine) or control (0 mg; placebo) gum for 5 min following 90 min of soccer-specific exercise. Perceptual-cognitive skills (i.e., passing accuracy, reaction time, composure, and adaptability) were assessed using a soccer-specific virtual reality simulator, collected pre- and posttrial. Neuromuscular performance (reactive-strength index, vertical jump height, absolute and relative peak power output, and negative vertical displacement) and sprint performance (15 and 30 m) were measured at pretrial, half-time, 90 min, and posttrial. Caffeine gum attenuated declines in reaction time (pre: 90.8 ± 0.8 AU to post: 90.7 ± 0.8 AU) by a further 4.2% than placebo (pre: 92.1 ± 0.8 AU to post: 88.2 ± 0.8 AU; p < .01). Caffeine gum reduced composure by 4.7% (pre: 69.1 ± 0.8 AU to post: 65.9 ± 0.8 AU) versus placebo (pre: 68.8 ± 0.8 AU to post: 68.3 ± 0.8 AU; p < .01). Caffeine gum did not influence any other variables (p > .05). Where caffeine gum is consumed by players prior to extra-time, reaction time increases but composure may be compromised, and neuromuscular and sprint performance remain unchanged. Future work should assess caffeine gum mixes with substances like L-theanine that promote a relaxed state under stressful conditions.
Long-Term Evaluation of Lipid Profile Changes in Olympic Athletes.
Di Gioia G, Buzzelli L, Maestrini V … +8 more , Squeo MR, Lemme E, Monosilio S, Serdoz A, Fiore R, Zampaglione D, Segreti A, Pelliccia A
Int J Sport Nutr Exerc Metab · 2024 Sep · PMID 38917988 · Publisher ↗
Dyslipidemia is a major contributor to the development of atherosclerotic cardiovascular disease. Despite high level of physical activity, athletes are not immune from dyslipidemia, but longitudinal data on the variation...
Dyslipidemia is a major contributor to the development of atherosclerotic cardiovascular disease. Despite high level of physical activity, athletes are not immune from dyslipidemia, but longitudinal data on the variation of lipids are currently lacking. We sought to assess lipid profile changes over time in Olympic athletes practicing different sports disciplines (power, skills, endurance, and mixed). We enrolled 957 consecutive athletes evaluated from London 2012 to Beijing 2022 Olympic Games. Dyslipidemia was defined as low-density lipoprotein (LDL) ≥115 mg/dl, high-density lipoprotein (HDL) <40 mg/dl for males, or HDL <50 mg/dl for females. Hypertriglyceridemia was defined as triglycerides >150 mg/dl. At the follow-up, a variation of ±40 mg/dl for LDL, ±6 mg/dl for HDL, and ±50 mg/dl for triglycerides was considered relevant. Athletes with follow-up <10 months or taking lower lipid agents were excluded. Follow-up was completed in 717 athletes (74.9%), with a mean duration of 55.6 months. Mean age was 27.2 ± 4.8 years old, 54.6% were male (n = 392). Overall, 19.8% (n = 142) athletes were dyslipidemic at both blood tests, being older, practicing nonendurance sports, and predominantly male. In 69.3% (n = 129) of those with elevated LDL at t0, altered values were confirmed at follow-up, while the same occurred in 36.5% (n = 15) with hypo-HDL and 5.3% (n = 1) in those with elevated triglycerides. Weight and fat mass percentage modifications did not affect lipid profile variation. LDL hypercholesterolemia tends to persist over time especially among male, older, and nonendurance athletes. LDL hypercholesterolemia detection in athletes should prompt early preventive intervention to reduce the risk of future development of atherosclerotic disease.
Effects of Phenylcapsaicin on Intraocular and Ocular Perfusion Pressure During a 30-Min Cycling Task: A Placebo-Controlled, Triple-Blind, Balanced Crossover Study.
Lara Vázquez PM, Morenas-Aguilar MD, Chacón Ventura S … +5 more , Jiménez-Martínez P, Alix-Fages C, García Ramos A, Vera J, Redondo B
Int J Sport Nutr Exerc Metab · 2024 Sep · PMID 38917985 · Publisher ↗
The main objective of this placebo-controlled, triple-blind, balanced crossover study was to assess the acute effects of phenylcapsaicin (PC) intake (2.5 mg) on intraocular pressure (IOP), ocular perfusion pressure (OPP)...
The main objective of this placebo-controlled, triple-blind, balanced crossover study was to assess the acute effects of phenylcapsaicin (PC) intake (2.5 mg) on intraocular pressure (IOP), ocular perfusion pressure (OPP), and heart rate (HR) during a 30-min cycling task performed at 15% of the individual maximal power. Twenty-two healthy young adults performed the cycling task 45 min after ingesting PC or placebo. IOP was measured with a rebound tonometer before exercise, during cycling (every 6 min), and after 5 and 10 min of recovery. OPP was assessed before and after exercise. HR was monitored throughout the cycling task. We found an acute increase of IOP levels related to PC consumption while cycling (mean difference = 1.91 ± 2.24 mmHg; p = .007, ηp2=.30), whereas no differences were observed for OPP levels between the PC and placebo conditions (mean difference = 1.33 ± 8.70 mmHg; p = .608). Mean HR values were higher after PC in comparison with placebo intake (mean difference = 3.11 ± 15.87 bpm, p = .019, ηp2=.24), whereas maximum HR did not differ between both experimental conditions (p = .199). These findings suggest that PC intake before exercise should be avoided when reducing IOP levels is desired (e.g., glaucoma patients or those at risk). Future studies should determine the effects of different ergogenic aids on IOP and OPP levels with other exercise configurations and in the long term.
Acute and Chronic Weight-Making Practice in Professional Mixed Martial Arts Athletes: An Analysis of 33 Athletes Across 80 Fights.
Reale R, Wang J, Hu Stull C … +3 more , French D, Amasinger D, Wang R
Int J Sport Nutr Exerc Metab · 2024 Sep · PMID 38871343 · Publisher ↗
Mixed martial arts' popularity has increased in recent years, alongside descriptive research and evidence-based performance recommendations. Guidelines for (both chronic and acute) weight making exist; however, how these...
Mixed martial arts' popularity has increased in recent years, alongside descriptive research and evidence-based performance recommendations. Guidelines for (both chronic and acute) weight making exist; however, how these translate in real-life scenarios and detailed investigations on practices in larger groups deserve attention. The present study examined the body mass (BM) and composition of 33 professional mixed martial arts athletes preparing for 80 fights. Athletes were supported by on-site dietitians, who encouraged evidence-based practices. Fasted BM was measured throughout the last ∼10 days before all bouts (acute weight management phase). A subset of athletes had body composition assessed before and after the chronic weight loss phase for 40 fights. Most athletes engaged in chronic BM loss, and all engaged in acute weight loss. Many lost fat-free mass (FFM) during the chronic phase, with rates of BM loss <0.5% best preserving FFM. Regardless of losses, the present athletes possessed greater FFM than other combat sport athletes and engaged in greater acute weight loss. Dehydration in the 24-48 hr before the weigh-in was not reflective of weight regain after the weigh-in, rather BM 7-10 days before the weigh-in was most reflective. These findings suggest that many mixed martial arts athletes could increase FFM at the time of competition by maintaining leaner physiques outside of competition and/or allowing increased time to reduce BM chronically. Acutely, athletes can utilize evidence-based protocols, eliminating carbohydrates, fiber, sodium, and finally fluid in a staged approach, before the weigh-in, reducing the amount of sweating required, thus theoretically better protecting health and preserving performance.
Test-Retest Reliability of Running Economy and Metabolic and Cardiorespiratory Parameters During a Multistage Incremental Treadmill Test in Male Middle- and Long-Distance Runners.
Brady AJ, Roantree M, Egan B
Int J Sport Nutr Exerc Metab · 2024 Sep · PMID 38823796 · Publisher ↗
This study investigated the test-retest reliability of running economy (RE) and metabolic and cardiorespiratory parameters related to endurance running performance using a multistage incremental treadmill test. On two oc...
This study investigated the test-retest reliability of running economy (RE) and metabolic and cardiorespiratory parameters related to endurance running performance using a multistage incremental treadmill test. On two occasions separated by 21-28 days, 12 male middle- and long-distance runners ran at 10, 11, 12, 13, and 14 km/hr for 8 min each stage, immediately followed by a ramp test to volitional exhaustion. Carbohydrate (10% maltodextrin solution) was consumed before and during the test to provide ∼1 g/min of exercise. RE, minute ventilation (V˙E), oxygen consumption (V˙O2), carbon dioxide production (V˙CO2), respiratory exchange ratio (RER), heart rate (HR), ratings of perceived exertion (RPE), and blood glucose and lactate concentrations were recorded for each stage and at volitional exhaustion. Time-to-exhaustion (TTE) and peak oxygen consumption (V˙O2peak) during the ramp test were also recorded. Absolute reliability, calculated as the coefficient of variation (CV) between repeated measures, ranged from 2.3% to 3.1% for RE, whereas relative reliability, calculated as the intraclass correlation coefficient (ICC), ranged from .42 to .79. V˙E, V˙O2, V˙O2peak, V˙CO2, RER, and HR had a CV of 1.1%-4.3% across all stages. TTE and RPE had a CV of 7.2% and 2.3%-10.8%, respectively, while glucose and lactate had a CV of 4.0%-17.8%. All other parameters, except for blood glucose, were demonstrated to have good-to-excellent relative reliability assessed by ICC. Measures of RE, V˙O2peak, and TTE were reliable during this two-phase multistage incremental treadmill test in a cohort of trained and highly trained male middle- and long-distance runners.
Energetics of a World-Tour Female Road Cyclist During a Multistage Race (Tour de France Femmes).
Areta JL, Meehan E, Howe G … +1 more , Redman LM
Int J Sport Nutr Exerc Metab · 2024 Sep · PMID 38796175 · Publisher ↗
Despite the increased popularity of female elite road cycling, research to inform the fueling requirements of these endurance athletes is lacking. In this case study, we report for the first time the energetics of a fema...
Despite the increased popularity of female elite road cycling, research to inform the fueling requirements of these endurance athletes is lacking. In this case study, we report for the first time the energetics of a female world-tour cyclist competing in the 2023 Tour de France Femmes, an 8-day race of the Union Cycliste Internationale. The 29-year-old athlete presented with oligomenorrhea and low T3 before the race. Total daily energy expenditure assessed with the doubly labeled water technique was 7,572 kcal/day (∼4.3 physical activity levels), among the highest reported in the literature to date for a female. Crank-based mean maximal power was consistent with female world-tour cyclists (5 min, mean 342 W, 4.8 W/kg; 20 min 289 W, 4.1 W/kg). The average daily energy intake measured with the remote food photography method (Stage Days 1-7) was 5,246 kcal and carbohydrate intake was 13.7 g/kg (range 9.7-15.9 g/kg), and 84 g/hr during stages, and an average fat intake of 15% of daily energy intake. An estimated 2,326 kcal/day energy deficit was evidenced in a 2.2 kg decrease in body mass. Notwithstanding the high carbohydrate intake, the athlete was unable to match the energy requirements of the competition. Despite signs of energy deficiency preexisting (oligomenorrhea and low T3), and other further developing during the race (weight loss), performance was in line with that of other world-tour cyclists and a best personal performance was recorded for the last stage. This case study emphasizes the need for further research to inform energy requirements for female athletes' optimal performance and health.
Skimmed, Lactose-Free Milk Ingestion Postexercise: Rehydration Effectiveness and Gastrointestinal Disturbances Versus Water and a Sports Drink in Physically Active People.
Aragón-Vargas LF, Garzón-Mosquera JC, Montoya-Arroyo JA
Int J Sport Nutr Exerc Metab · 2024 Sep · PMID 38789098 · Publisher ↗
Postexercise hydration is fundamental to replace fluid loss from sweat. This study evaluated rehydration and gastrointestinal (GI) symptoms for each of three beverages: water (W), sports drink (SD), and skimmed, lactose-...
Postexercise hydration is fundamental to replace fluid loss from sweat. This study evaluated rehydration and gastrointestinal (GI) symptoms for each of three beverages: water (W), sports drink (SD), and skimmed, lactose-free milk (SLM) after moderate-intensity cycling in the heat. Sixteen college students completed three exercise sessions each to lose ≈2% of their body mass. They drank 150% of body mass loss of the drink assigned in randomized order; net fluid balance, diuresis, and GI symptoms were measured and followed up for 3 hr after completion of fluid intake. SLM showed higher fluid retention (∼69%) versus W (∼40%; p < .001); SD (∼56%) was not different from SLM or W (p > .05). Net fluid balance was higher for SLM (-0.26 kg) and SD (-0.42 kg) than W (-0.67 kg) after 3 hr (p < .001), resulting from a significantly lower diuresis with SLM. Reported GI disturbances were mild and showed no difference among drinks (p > .05) despite ingestion of W (1,992 ± 425 ml), SD (1,999 ± 429 ml), and SLM (1,993 ± 426 ml) in 90 min. In conclusion, SLM was more effective than W for postexercise rehydration, showing greater fluid retention for the 3-hr follow-up and presenting with low-intensity GI symptoms similar to those with W and SD. These results confirm that SLM is an effective option for hydration after exercise in the heat.
Myths and Methodologies: Standardisation in Human Physiology Research-Should We Control the Controllables?
Merrell LH, Perkin OJ, Bradshaw L … +17 more , Collier-Bain HD, Collins AJ, Davies S, Eddy R, Hickman JA, Nicholas AP, Rees D, Spellanzon B, James LJ, McKay AKA, Smith HA, Turner JE, Koumanov F, Maher J, Thompson D, Gonzalez JT, Betts JA
Int J Sport Nutr Exerc Metab · 2024 Jul · PMID 38763509 · Publisher ↗
The premise of research in human physiology is to explore a multifaceted system whilst identifying one or a few outcomes of interest. Therefore, the control of potentially confounding variables requires careful thought r...
The premise of research in human physiology is to explore a multifaceted system whilst identifying one or a few outcomes of interest. Therefore, the control of potentially confounding variables requires careful thought regarding the extent of control and complexity of standardisation. One common factor to control prior to testing is diet, as food and fluid provision may deviate from participants' habitual diets, yet a self-report and replication method can be flawed by under-reporting. Researchers may also need to consider standardisation of physical activity, whether it be through familiarisation trials, wash-out periods, or guidance on levels of physical activity to be achieved before trials. In terms of pharmacological agents, the ethical implications of standardisation require researchers to carefully consider how medications, caffeine consumption and oral contraceptive prescriptions may affect the study. For research in females, it should be considered whether standardisation between- or within-participants in regards to menstrual cycle phase is most relevant. The timing of measurements relative to various other daily events is relevant to all physiological research and so it can be important to standardise when measurements are made. This review summarises the areas of standardisation which we hope will be considered useful to anyone involved in human physiology research, including when and how one can apply standardisation to various contexts.
Effect of Menstrual Cycle Phase and Hormonal Contraceptives on Resting Metabolic Rate and Body Composition.
Kuikman MA, McKay AKA, Minahan C … +9 more , Harris R, Elliott-Sale KJ, Stellingwerff T, Smith ES, McCormick R, Tee N, Skinner J, Ackerman KE, Burke LM
Int J Sport Nutr Exerc Metab · 2024 Jul · PMID 38653456 · Publisher ↗
The cyclical changes in sex hormones across the menstrual cycle (MC) are associated with various biological changes that may alter resting metabolic rate (RMR) and body composition estimates. Hormonal contraceptive (HC)...
The cyclical changes in sex hormones across the menstrual cycle (MC) are associated with various biological changes that may alter resting metabolic rate (RMR) and body composition estimates. Hormonal contraceptive (HC) use must also be considered given their impact on endogenous sex hormone concentrations and synchronous exogenous profiles. The purpose of this study was to determine if RMR and dual-energy X-ray absorptiometry body composition estimates change across the MC and differ compared with HC users. This was accomplished during a 5-week training camp involving naturally cycling athletes (n = 11) and HC users (n = 7 subdermal progestin implant, n = 4 combined monophasic oral contraceptive pill, n = 1 injection) from the National Rugby League Indigenous Women's Academy. MC phase was retrospectively confirmed via serum estradiol and progesterone concentrations and a positive ovulation test. HC users had serum estradiol and progesterone concentrations assessed at the time point of testing. Results were analyzed using general linear mixed model. There was no effect of MC phase on absolute RMR (p = .877), relative RMR (p = .957), or dual-energy X-ray absorptiometry body composition estimates (p > .05). There was no effect of HC use on absolute RMR (p = .069), relative RMR (p = .679), or fat mass estimates (p = .766), but HC users had a greater fat-free mass and lean body mass than naturally cycling athletes (p = .028). Our findings suggest that RMR and dual-energy X-ray absorptiometry body composition estimates do not significantly differ due to changes in sex hormones in a group of athletes, and measurements can be compared between MC phases or with HC usage without variations in sex hormones causing additional noise.
Contaminants in Dietary Supplements: Toxicity, Doping Risk, and Current Regulation.
Zapata-Linares J, Gervasini G
Int J Sport Nutr Exerc Metab · 2024 Jul · PMID 38653450 · Publisher ↗
Athletes, both amateur and professional, often resort to the consumption of nutritional supplements without professional supervision and without being aware of the risks they may entail. We conducted an exhaustive litera...
Athletes, both amateur and professional, often resort to the consumption of nutritional supplements without professional supervision and without being aware of the risks they may entail. We conducted an exhaustive literature search to determine the most common substances found as contaminants in dietary supplements. For each substance, we analyzed its mechanism of action, clinical indication, health risk, and putative use as doping agent. In addition, we evaluated the current regulation of these supplements. Contamination of nutritional supplements (accidental or intentional), especially with steroids and stimulants, is a hazardous situation. The prolonged consumption of these products without being aware of their composition can cause serious health risks and, in the case of professional athletes, a possible sanction for doping.
Omega-3 Status Evaluation in Australian Female Rugby League Athletes: Ad Libitum Fish Oil Provision Results in a Varied Omega-3 Index.
Anthony R, Jaffrey N, Byron C … +2 more , Peoples GE, Macartney MJ
Int J Sport Nutr Exerc Metab · 2024 Jul · PMID 38648883 · Publisher ↗
Optimal omega-3 status, influenced by increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is vital for physiological health. This study investigated the impact of ad libitum fish oil supplemen...
Optimal omega-3 status, influenced by increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is vital for physiological health. This study investigated the impact of ad libitum fish oil supplementation on the omega-3 status of female athletes in a professional rugby league team during a competitive season. Twenty-four (n = 24) athletes participated, and their omega-3 status was assessed using the Omega-3 Index (O3I) and arachidonic acid (AA) to EPA ratio through finger-prick blood samples taken at the start and end of the season. They were given access to a fish oil supplement (PILLAR Performance, Australia) with a recommended daily dose of four capsules per day (2,160 mg EPA and 1,440 mg docosahexaenoic acid). At the beginning of the season, the group mean O3I was 4.77% (95% confidence interval [CI: 4.50, 5.04]) and the AA to EPA ratio was 14.89 (95% CI [13.22, 16.55]). None of the athletes had an O3I exceeding 8%. By the season's end, the O3I was a significantly increased to 7.28% (95% CI [6.64, 7.93], p < .0001) and AA to EPA ratio significantly decreased to a mean of 6.67 (95% CI [5.02, 8.31], p < .0001), driven primarily by the significant increase in EPA of +1.14% (95% CI [0.77, 1.51], p < .0001). However, these changes were varied between the athletes and most likely due to compliance. This study has demonstrated that using the objective O3I feedback scale is possible with elite female rugby athletes, but individual strategies will be required to achieve daily intake targets of EPA + DHA.
Coingestion of Collagen With Whey Protein Prevents Postexercise Decline in Plasma Glycine Availability in Recreationally Active Men.
Aussieker T, Janssen TAH, Hermans WJH … +6 more , Holwerda AM, Senden JM, van Kranenburg JMX, Goessens JPB, Snijders T, van Loon LJC
Int J Sport Nutr Exerc Metab · 2024 Jul · PMID 38604602 · Publisher ↗
Whey protein ingestion during recovery from exercise increases myofibrillar but not muscle connective protein synthesis rates. It has been speculated that whey protein does not provide sufficient glycine to maximize post...
Whey protein ingestion during recovery from exercise increases myofibrillar but not muscle connective protein synthesis rates. It has been speculated that whey protein does not provide sufficient glycine to maximize postexercise muscle connective protein synthesis rates. In the present study, we assessed the impact of coingesting different amounts of collagen with whey protein as a nutritional strategy to increase plasma glycine availability during recovery from exercise. In a randomized, double-blind, crossover design, 14 recreationally active men (age: 26 ± 5 years; body mass index: 23.8 ± 2.1 kg·m-2) ingested in total 30 g protein, provided as whey protein with 0 g (WHEY), 5 g (WC05); 10 g (WC10), and 15 g (WC15) of collagen protein immediately after a single bout of resistance exercise. Blood samples were collected frequently over 6 hr of postexercise recovery to assess postprandial plasma amino acid kinetics and availability. Protein ingestion strongly increased plasma amino acid concentrations (p < .001) with no differences in plasma total amino acid availability between treatments (p > .05). The postprandial rise in plasma leucine and essential amino acid availability was greater in WHEY compared with the WC10 and WC15 treatments (p < .05). Plasma glycine and nonessential amino acid concentrations declined following whey protein ingestion but increased following collagen coingestion (p < .05). Postprandial plasma glycine availability averaged -8.9 ± 5.8, 9.2 ± 3.7, 23.1 ± 6.5, and 39.8 ± 11.0 mmol·360 min/L in WHEY, WC05, WC10, and WC15, respectively (incremental area under curve values, p < .05). Coingestion of a small amount of collagen (5 g) with whey protein (25 g) is sufficient to prevent the decline in plasma glycine availability during recovery from lower body resistance-type exercise in recreationally active men.
Caffeine, but Not Creatine, Improves Anaerobic Power Without Altering Anaerobic Capacity in Healthy Men During a Wingate Anaerobic Test.
Marinho AH, Silva-Cavalcante MD, Cristina-Souza G … +5 more , Sousa FAB, Ataide-Silva T, Bertuzzi R, de Araujo GG, Lima-Silva AE
Int J Sport Nutr Exerc Metab · 2024 May · PMID 38458183 · Publisher ↗
There is a lack of evidence on the additional benefits of combining caffeine (CAF) and creatine (CRE) supplementation on anaerobic power and capacity. Thus, the aim of the present study was to test the effects of combine...
There is a lack of evidence on the additional benefits of combining caffeine (CAF) and creatine (CRE) supplementation on anaerobic power and capacity. Thus, the aim of the present study was to test the effects of combined and isolated supplementation of CAF and CRE on anaerobic power and capacity. Twenty-four healthy men performed a baseline Wingate anaerobic test and were then allocated into a CRE (n = 12) or placebo (PLA; n = 12) group. The CRE group ingested 20 g/day of CRE for 8 days, while the PLA group ingested 20 g/day of maltodextrin for the same period. On the sixth and eighth days of the loading period, both groups performed a Wingate anaerobic test 1 hr after either CAF (5 mg/kg of body mass; CRE + CAF and PLA + CAF conditions) or PLA (5 mg/kg of body mass of cellulose; CRE + PLA and PLA + PLA conditions) ingestion. After the loading period, changes in body mass were greater (p < .05) in the CRE (+0.87 ± 0.23 kg) than in the PLA group (+0.13 ± 0.27 kg). In both groups, peak power was higher (p = .01) in the CAF (1,033.4 ± 209.3 W) than in the PLA trial (1,003.3 ± 204.4 W), but mean power was not different between PLA and CAF trials (p > .05). In conclusion, CAF, but not CRE ingestion, increases anaerobic power. Conversely, neither CRE nor CAF has an effect on anaerobic capacity.
Becoming a World Champion Powerlifter at 71 Years of Age: It Is Never Too Late to Start Exercising.
Fuchs CJ, Trommelen J, Weijzen MEG … +4 more , Smeets JSJ, van Kranenburg J, Verdijk LB, van Loon LJC
Int J Sport Nutr Exerc Metab · 2024 Jul · PMID 38458181 · Publisher ↗
This case study assessed body composition, muscle strength, cardiorespiratory fitness, and metabolic health of the present female world champion powerlifter in the 70+ age category who started resistance exercise trainin...
This case study assessed body composition, muscle strength, cardiorespiratory fitness, and metabolic health of the present female world champion powerlifter in the 70+ age category who started resistance exercise training at 63 years of age with no prior experience with structured exercise training. Measures of body composition (magnetic resonance imaging, computed tomography, and dual-energy X-ray absorptiometry scanning, leg volume); strength (one-repetition maximum leg press and extension, maximum voluntary contraction, and handgrip strength); physical function (short physical performance battery); cardiorespiratory fitness (peak oxygen consumption); and metabolic health (oral glucose tolerance test) were assessed. In addition, a muscle biopsy was collected to assess muscle fiber type distribution and cross-sectional area (CSA). Where possible, data were compared with previously (un)published sex- and age-matched data using z scores. Skeletal muscle mass index was calculated by dividing limb muscle mass by height squared. Data from the control groups are expressed as mean ± 95% confidence interval. Our participant (age: 71 years; body mass: 64.5 kg; body mass index: 27.6 kg/m2) reported a good bone mineral density of 1.09 g/cm2 (T score between -1 and +1) and very low values of abdominal and organ body fat (i.e., between 20% and 70% lower compared with a reference group of postmenopausal women). In addition, she showed a 33% greater skeletal muscle mass index when compared with healthy, older female control subjects (7.9 vs. 5.9 [5.7-6.2] kg/m2; n = 61) as well as 37% greater muscle quadriceps CSA (63.8 vs. 46.6 [44.5-48.7] cm2; n = 48) and 46% greater Type II muscle fiber CSA (4,536 vs. 3,097 [2,707-3,488] μm2; n = 19). Absolute leg press muscle strength was 36% greater (190 vs. 140 [132-147] kg; n = 30) and handgrip strength was 33% greater (33 vs. 25 [23-26] kg; n = 48) when compared with healthy, age-matched controls. In conclusion, even for resistance exercise naïve individuals, starting exercise at an advanced age can lead to improvements in body composition and muscle strength allowing older adults to reduce the risk for developing metabolic syndrome, live independently, and even compete at a world class level.
Trehalose Improved 20-min Cycling Time-Trial Performance After 100-min Cycling in Amateur Cyclists.
de Oliveira NG, de Oliveira LF, da Silva RP … +9 more , Oliveira TN, Möller GB, Murasaki J, Ramires MA, Azevedo RA, Artioli GG, Roschel H, Gualano B, Saunders B
Int J Sport Nutr Exerc Metab · 2024 Jul · PMID 38458180 · Publisher ↗
Carbohydrate (CHO) supplementation during endurance exercise can improve performance. However, it is unclear whether low glycemic index (GI) CHO leads to differential ergogenic and metabolic effects compared with a stand...
Carbohydrate (CHO) supplementation during endurance exercise can improve performance. However, it is unclear whether low glycemic index (GI) CHO leads to differential ergogenic and metabolic effects compared with a standard high GI CHO. This study investigated the ergogenic and metabolic effects of CHO supplementation with distinct GIs, namely, (a) trehalose (30 g/hr), (b) isomaltulose (30 g/hr), (c) maltodextrin (60 g/hr), and (d) placebo (water). In this double-blind, crossover, counterbalanced, placebo-controlled study, 13 male cyclists cycled a total of 100 min at varied exercise intensity (i.e., 10-min stages at 1.5, 2.0, and 2.5 W/kg; repeated three times plus two 5-min stages at 1.0 W/kg before and after the protocol), followed by a 20-min time trial on four separated occasions. Blood glucose and lactate (every 20 min), heart rate, and ratings of perceived exertion were collected throughout, and muscle biopsies were taken before and immediately after exercise. The results showed that trehalose improved time-trial performance compared with placebo (total work done 302 ± 39 vs. 287 ± 48 kJ; p = .01), with no other differences between sessions (all p ≥ .07). Throughout the 100-min protocol, blood glucose was higher with maltodextrin compared with the other supplements at all time points (all p < .05). Heart rate, ratings of perceived exertion, muscle glycogen content, blood glucose, and lactate were not different between conditions when considering the 20-min time trial (all p > .05). Trehalose supplementation throughout endurance exercise improved cycling performance and appears to be an appropriate CHO source for exercise tasks up to 2 hr. No ergogenic superiority between the different types of CHO was established.
Cold Ambient Temperature Does Not Alter Subcutaneous Abdominal Adipose Tissue Lipolysis and Blood Flow in Endurance-Trained Cyclists.
Bach CW, Saracino PG, Baur DA … +3 more , Willingham BD, Ruby BC, Ormsbee MJ
Int J Sport Nutr Exerc Metab · 2024 May · PMID 38330938 · Publisher ↗
This study sought to investigate the effect of cold ambient temperature on subcutaneous abdominal adipose tissue (SCAAT) lipolysis and blood flow during steady-state endurance exercise in endurance-trained cyclists. Ten...
This study sought to investigate the effect of cold ambient temperature on subcutaneous abdominal adipose tissue (SCAAT) lipolysis and blood flow during steady-state endurance exercise in endurance-trained cyclists. Ten males (age: 23 ± 3 years; peak oxygen consumption: 60.60 ± 4.84 ml·kg-1·min-1; body fat: 18.4% ± 3.5%) participated in baseline lactate threshold (LT) and peak oxygen consumption testing, two familiarization trials, and two experimental trials. Experimental trials consisted of cycling in COLD (3 °C; 42% relative humidity) and neutral (NEU; 19 °C; 39% relative humidity) temperatures. Exercise consisted of 25 min cycling at 70% LT and 25 min at 90% LT. In situ SCAAT lipolysis and blood flow were measured via microdialysis. Heart rate, core temperature, carbohydrate and fat oxidation, blood glucose, and blood lactate were also measured. Heart rate, core temperature, oxygen consumption, and blood lactate increased with exercise but were not different between COLD and NEU. SCAAT blood flow did not change from rest to exercise or between COLD and NEU. Interstitial glycerol increased during exercise (p < .001) with no difference between COLD and NEU. Fat oxidation increased (p < .001) at the onset of exercise and remained elevated thereafter with no difference between COLD and NEU. Carbohydrate oxidation increased with increasing exercise intensity and was greater at 70% LT in COLD compared to NEU (p = .030). No differences were observed between conditions for any other variable. Cycling exercise increased SCAAT lipolysis but not blood flow. Ambient temperature did not alter SCAAT metabolism, SCAAT blood flow, or fat oxidation in well-trained cyclists, though cold exposure increased whole-body carbohydrate oxidation at lower exercise intensities.
Energy Expenditure of Elite Male and Female Professional Tennis Players During Habitual Training.
Ellis DG, Morton JP, Close GL … +1 more , Donovan TF
Int J Sport Nutr Exerc Metab · 2024 May · PMID 38281487 · Publisher ↗
Understanding the daily energy expenditure of athletes during training is important to support recovery, adaptation, and the maintenance of performance. The aim of the current research was to assess the total daily energ...
Understanding the daily energy expenditure of athletes during training is important to support recovery, adaptation, and the maintenance of performance. The aim of the current research was to assess the total daily energy expenditure (TDEE) and the acute energy expenditure (EE) of tennis training sessions during habitual training of elite tennis players. Using a cohort study design, 27 (n = 10, male; age; 22.3 ± 3.2 years and n = 17, female; age: 23.8 ± 3.5 years) elite singles tennis players were assessed for TDEE and tennis training EE. Using Actiheart activity monitors during a 2- to 5-day training period, male players were analyzed for 26 days and 33 (1.3 ± 0.5 sessions/day) tennis training sessions, and female players for 43 days and 58 (1.2 ± 0.4 sessions/day) tennis training sessions. Male TDEE (4,708 ± 583 kcal/day) was significantly higher than female (3,639 ± 305 kcal/day). Male absolute and relative tennis training EEs (10.2 ± 2.3 kcal/min and 7.9 ± 1.4 kcal·hr-1·kg-1) were significantly higher than those of females (7.6 ± 1.0 kcal/min and 6.8 ± 0.9 kcal·hr-1·kg-1). The resting metabolic rate was assessed via indirect calorimetry. The physical activity level for both groups was 2.3 AU. The TDEE of male and female players during habitual training now highlights the continual cycle of high energy demands experienced by the elite tennis player. The broad ranges of TDEE and EE reported here suggest individual assessment and nutritional planning be prioritized, with a particular focus on carbohydrate requirements.
Timing of Caffeine Ingestion Does Not Improve Three-Point Shooting Accuracy in College Basketball Players.
Tan ZS, Sim RYY, Kawabata M … +3 more , Low DY, Wang Y, Burns SF
Int J Sport Nutr Exerc Metab · 2024 May · PMID 38266631 · Publisher ↗
This study investigated the effects of the timing of caffeine (3 mg/kg body mass) ingestion on three-point shooting accuracy and other performance parameters during a basketball exercise simulation test (BEST). Eighteen...
This study investigated the effects of the timing of caffeine (3 mg/kg body mass) ingestion on three-point shooting accuracy and other performance parameters during a basketball exercise simulation test (BEST). Eighteen college basketball players (mean ± SD: age = 24.4 ± 1.5 years, height = 181.7 ± 9.5 cm, body mass = 80.9 ± 13.2 kg) underwent one familiarization trial and three main conditions in a randomized order: (a) placebo (maltodextrin) and placebo, (b) caffeine and placebo, and (c) placebo and caffeine. Participants ingested either the placebo or caffeine pill 75 and 15 min before performing four quarters of the BEST and a three-point shooting protocol. During each quarter, participants completed 16 rounds of the BEST and ten three-point shots. Vertical jump height, 6 m sprint timing, BEST completion timing, three-point shooting accuracy, heart rate, rate of perceived exertion, blood glucose, blood lactate, and psychological measures pertaining to performance were measured. The BEST completion timing differed among conditions (placebo and placebo = 26.4 ± 2.0 s, caffeine and placebo = 25.8 ± 2.0 s, placebo and caffeine = 25.9 ± 2.1 s; p = .031) but not three-point shooting accuracy (placebo and placebo = 12.33 ± 4.10; caffeine and placebo = 12.61 ± 2.81; placebo and caffeine = 11.67 ± 3.77; p = .648), vertical jump height, or sprint times. Manipulating ingestion timing of caffeine did not improve three-point shooting accuracy, vertical jump height, or 6 m sprint timings, but caffeine can improve performance times during simulated basketball exercise irrespective of ingestion timing.
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