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Volume 34 (2024): Issue 6 (Nov 2024)

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Body Mass Management Practices of Olympic Weightlifting Athletes

Amie M. Cox, Carl Langan-Evans, David Jenkins, Reid Reale, Fiona Pelly, and Gary J. Slater

This study explored the body mass (BM) management practices among competitive male and female Olympic weightlifting athletes, hypothesizing that athletes compete in lighter weight categories than their habitual training weight (i.e., making weight). Utilizing a validated, anonymous survey, data were collected from 149 Olympic weightlifting athletes (>18 years; female = 94). The survey comprised five sections: demographics, training/competition history, weight history, source of influence, and BM management practices. The prevalence, magnitude, and methods employed for BM management were analyzed with subgroup analysis using one-way analysis of variance. Post hoc testing including Spearman’s rho and chi-square analysis was completed when a significant effect was found. Three quarters (76%) of athletes acknowledged using chronic weight loss and/or acute weight loss strategies to make weight. Usual BM loss (2%–3%) in the week before competition was within recommended guidelines. Gradual dieting, fluid restriction, and low food weight, high-calorie options were the most commonly used BM management strategies. Female athletes were more likely to use gradual dieting (p = .043; r = .104) and were less likely to increase their exercise (p = .046; r = −.105) and utilize fasting (p = .038; r = .05) compared with their male counterparts. Women further identified dietitians/nutritionists (p = .006; r = .022) as a highly influential source of information. This research offers new insights into the BM management practices of Olympic weightlifting athletes, identifying that the majority of athletes compete at a BM lighter than their habitual training weight, achieved using a range of chronic weight loss and acute weight loss strategies.

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Acute Effects of Taurine Supplementation on Maximal Fat Oxidation and FATmax in Recreational Endurance Runners: A Randomized, Placebo-Controlled, Crossover, and Triple-Blinded Study

Abdolrahman Ghazzagh, Alireza Naderi, Hamid Agha-Alinejad, Ali Livani, Mohsen Sarlak, Samaneh Aghamohammadi, and Bryan Saunders

Taurine (TAU) has been shown to improve time to exhaustion (TTE) and fat oxidation during exercise; however, no studies have examined the effect of acute TAU supplementation on maximal fat oxidation (MFO) and related intensity to MFO (FATmax). Our study aimed to investigate the effect of acute TAU supplementation on MFO, FATmax, VO2peak, and TTE. Eleven recreationally trained male endurance runners performed three incremental running tests. The first visit included a familiarization to the test, followed by two subsequent visits in which exercise was performed 90 min after ingestion of either 6-g TAU or placebo (PLA) using a triple-blind randomized crossover design. There was no effect of TAU on MFO (p = .89, d = −0.07, TAU: 0.48 ± 0.22 g/min; PLA: 0.49 ± 0.15 g/min or FATmax (p = .26, d = −0.66; TAU: 49.17 ± 15.86 % V ˙ O 2 peak ; PLA: 56.00 ± 13.27 % V ˙ O 2 peak ). TTE was not significantly altered (TAU: 1,444.8 ± 88.6 s; PLA: 1,447.6 ± 87.34 s; p = .65, d = −0.04). TAU did not show any effect on V ˙ O 2 peak in comparison with PLA (TAU: 58.9 ± 8.4 ml·kg−1·min−1; PLA: 56.5 ± 5.7 ml·kg−1·min−1, p = .47, d = 0.48). However, V ˙ O 2 TAU at most stages of exercise with large effect sizes ( η p 2 = .43 ). The acute ingestion of 6 g of TAU before exercise did not enhance MFO, FATmax, or TTE. However, it did increase the oxygen cost of running fixed intensities in recreationally trained endurance runners.

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Erratum. Effect of Menstrual Cycle Phase and Hormonal Contraceptives on Resting Metabolic Rate and Body Composition

International Journal of Sport Nutrition and Exercise Metabolism

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Exogenous Glucose Oxidation During Exercise Is Positively Related to Body Size

Abdullah Ijaz, Adam J. Collins, Alfonso Moreno-Cabañas, Louise Bradshaw, Katie Hutchins, James A. Betts, Tim Podlogar, Gareth A. Wallis, and Javier T. Gonzalez

There is little evidence that body size alters exogenous glucose oxidation rates during exercise. This study assessed whether larger people oxidize more exogenous glucose during exercise than smaller people. Fifteen cyclists were allocated into two groups based on body mass (SMALL, <70 kg body mass, n = 9, two females) or (LARGE, >70 kg body mass, n = 6) matched for lactate threshold (SMALL: 2.3 ± 0.4 W/kg, LARGE: 2.3 ± 0.3 W/kg). SMALL completed 120 min of cycling at 95% of lactate threshold1. LARGE completed two trials in a random order, one at 95% of lactate threshold1 (thereby exercising at the same relative intensity [RELATIVE]) and one at an absolute intensity matched to SMALL (ABSOLUTE). In all trials, cyclists ingested 90 g/hr of 13C-enriched glucose. Total exogenous glucose oxidation was (mean ± SD) 33 ± 8 g/hr in SMALL versus 45 ± 13 g/hr in LARGE-RELATIVE (mean difference: 13 g/hr, 95% confidence interval [2, 24] g/hr, p = .03). Large positive correlations were observed for measures of exogenous carbohydrate oxidation versus body size (body mass, height, and body surface area; e.g., body surface area vs. peak exogenous glucose oxidation, r = .85, 95% confidence interval [.51, .95], p < .01). When larger athletes reduced the intensity from RELATIVE to ABSOLUTE, total exogenous glucose oxidation was 39 ± 7 g/hr (p = .43 vs. LARGE-RELATIVE). In conclusion, the capacity for exogenous glucose oxidation is, on average, higher in larger athletes than smaller athletes during exercise. The extent to which this is due to higher absolute exercise intensity requires further research, but body size may be a consideration in tailoring sports nutrition guidelines for carbohydrate intake during exercise.

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Dietary Calcium-to-Phosphorous Ratio, Metabolic Risk Factors and Lipid Accumulation Product, Skeletal Muscle Mass, and Visceral Fat Area Among Healthy Young Individuals

Xuanshang Jin, Xiangchuan Jin, Wen Guan, and Maolin Tang

Background: Numerous studies have revealed the role of low dietary calcium-to-phosphorous ratio and low bone health. However, its possible role in visceral adiposity, skeletal muscle mass (SMM), and metabolic parameters has not been investigated before. Therefore, the aim of the current cross-sectional study was to evaluate the relation between dietary calcium-to-phosphorous ratio, metabolic risk factors, SMM, and visceral fat area (VFA) among physically active young individuals. Methods: In the current study, the sample was composed of 391 healthy young individuals (e.g., 205 men and 186 women), aged between 20 and 35 years old, who were engaged in moderate physical activity for at least 4 hr per week and were recruited thorough cluster sampling from seven sport clubs. Anthropometric measurements were performed, and VFA and SMM index (SMI) were calculated. Biochemical assays were also performed by standard kits. Data were analyzed by one-way analysis of variance, analysis of co-variance, and multinomial logistic regression analysis using SPSS software. Results: Those in the fourth quartile of dietary calcium-to-phosphorous ratio were more likely to have lower VFA (odds ratio [OR] = 0.98; 95% confidence interval [CI] [0.97, 0.99]; p = .023) and a nonsignificantly higher SMI (OR = 1.15; 95% CI [0.99, 1.34]; p = .058) after adjustment for the effects of confounders (e.g., age, gender, body mass index, physical activity level, dietary energy intake). Also, being in the third quartile of dietary calcium-to-phosphorous ratio made the subjects more susceptible to have lower insulin concentration (OR = 0.99; 95% CI [0.88, 0.93]; p = .026) in the adjusted model. Conclusion: The findings of the current study revealed that a higher dietary calcium-to-phosphorous ratio in the habitual diet was negatively associated with visceral adiposity and insulin concentrations and higher SMM among physically active young individuals. Further interventional studies are required to confer causality that was not inferable in the current study because of cross-sectional design.

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Intrasession Caffeine Intake and Cycling Performance After Accumulated Work: A Field-Based Study

Iván R. Sánchez-Redondo, Lidia B. Alejo, Carlos Revuelta, Raúl de Pablos, María Ibañez, Alberto Pérez-López, Alejandro Lucia, David Barranco-Gil, and Pedro L. Valenzuela

Background: Preexercise caffeine intake has proven to exert ergogenic effects on cycling performance. However, whether these benefits are also observed under fatigue conditions remains largely unexplored. We aimed to assess the effect of caffeine ingested during prolonged cycling on subsequent time-trial performance in trained cyclists. Methods: The study followed a triple-blinded, randomized, placebo-controlled cross-over design. Eleven well-trained junior cyclists (17 ± 1 years) performed a field-based 8-min time trial under “fresh” conditions (i.e., after their usual warm-up) or after two work-matched steady-state cycling sessions (total energy expenditure∼20 kJ/kg and ∼100 min duration). During the latter sessions, participants consumed caffeine (3 mg/kg) or a placebo ∼60 min before the time trial. We assessed power output, heart rate, and rating of perceived exertion during the time trial and mood state (Brunel Mood Scale) before and after each session. Results: No significant condition effect was found for the mean power output attained during the time trial (365 ± 25, 369 ± 31, and 364 32 W for “fresh,” caffeine, and placebo condition, respectively; p = .669). Similar results were found for the mean heart rate (p = .100) and rating of perceived exertion (p = 1.000) during the time trial and for the different mood domains (all p > .1). Conclusions: Caffeine intake during prolonged exercise seems to exert no ergogenic effects on subsequent time-trial performance in junior cyclists. Future studies should determine whether significant effects can be found with larger caffeine doses or after greater fatigue levels.

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Erratum. Sweat Mineral-Element Responses During 7 h of Exercise-Heat Stress

International Journal of Sport Nutrition and Exercise Metabolism

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Oral but Not Topical Sodium Bicarbonate Improves Repeated Sprint Performance During Simulated Soccer Match Play Exercise in Collegiate Athletes

William H. Gurton, Lewis A. Gough, Jason C. Siegler, Anthony Lynn, and Mayur K. Ranchordas

This study investigated the effect of oral and topical sodium bicarbonate (SB) on soccer-specific performance during simulated soccer exercise. In a block randomized, double-blind, crossover design, 10 collegiate male soccer players (stature: 181.7 ± 3.2 cm, body mass: 81.7 ± 10.5 kg) performed soccer-specific performance tests (countermovement jumps, Illinois agility, 8 × 25 m repeated sprints) throughout a 90-min soccer-specific aerobic field test (SAFT90) following 0.3 g/kg body mass SB in capsules (SB-ORAL), 0.9036 g/kg body mass PR Lotion (SB-LOTION), or placebo capsules and lotion (PLA). Soccer-specific performance tests were conducted pre-SAFT90, during half-time and post-SAFT90. Blood samples were analyzed for acid–base balance (pH; bicarbonate, HCO 3 ) and strong ions (sodium, Na+; potassium, K+). Average sprint times were quicker for SB-ORAL than PLA during half-time (3.7%; p = .049; g = .57) and post-SAFT90 (4.9%; p = .041; g = .66). SB-ORAL increased pH and HCO 3 prewarm-up and during half-time (p < .05), and lowered K+ during half-time (p = .035) compared with PLA. SB-LOTION increased pH (p = .019) and lowered K+ (p = .012) during half-time compared with PLA. SB-LOTION increased Na+ postexercise compared with PLA (p = .008). Repeated sprint times during simulated soccer exercise improved for SB-ORAL, which might have been mechanistically underpinned by elevated blood buffering capacity and greater regulation of strong ion concentration. Consuming SB in capsules is a more effective strategy than topical SB application for improving blood buffering capacity and repeated sprint performance throughout competitive soccer matches.

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Volume 34 (2024): Issue 5 (Sep 2024)