Journal of the International Society of Sports Nutrition最新文献

Aim: While it is well established that reducing ectopic fat can help prevent insulin resistance in individuals with overweight or obesity, it remains unclear whether diet alone, exercise alone, or their combination is most effective in reducing specific ectopic fat depots. Therefore, the objective of this study was to investigate the effects of diet-only, and combined diet-plus-exercise interventions versus exercise only on ectopic fat reduction, and weight loss in adults with overweight or obesity.

Methods: Web of Science, PubMed, and Scopus were searched for original articles, published until 1 March 2024 (no limitation on publication dates) that included diet only/or exercise and diet versus exercise alone on body weight, and ectopic fat in adults with overweight or obesity. Weighted mean differences (WMD) for body weight, liver fat, standardized mean differences (SMD) for visceral fat area (VFA), and intramuscular triglyceride (IMTG), and 95% confidence intervals (95% CI) were determined using random-effects models. Studies using noninvasive imaging techniques such as Computerized Tomography (CT), Magnetic Resonance Imaging (MRI), and hydrogen-based Magnetic Resonance Spectroscopy (H-MRs) for ectopic fat were included in this meta-analysis.

Results: A total of 17 studies, including 732 participants aged 24.27 to 70.5 years (309 participants with metabolic diseases, and 423 without metabolic diseases) and 38 intervention groups, met the inclusion criteria. The combined intervention of exercise and diet significantly reduced body weight compared to exercise alone [WMD = -2.85 kg, p = 0.001], with significant reductions observed in both adults with and without metabolic disease, and for interventions lasting more than 12 weeks. However, the combined intervention did not significantly reduce liver fat, VFA, or IMTG compared to exercise alone. Diet-only interventions significantly reduced body weight compared to exercise alone [WMD = -2.57 kg, p = 0.010], but did not significantly affect liver fat, VFA, or IMTG. Meta-regression indicated that weight loss was a significant moderator of the effect of combined interventions on VFA (coefficient: -0.15; p = 0.030), but not for other outcomes. Also, based on subgroup analysis by intervention duration, both exercise and calorie restriction interventions in long-term (more than 12 weeks) have been successful in decreasing VFA in adults with overweight/or obesity.

Conclusion: Combined exercise and dietary interventions are more effective than exercise alone in reducing body weight. While VFA was reduced following long-term interventions of exercise in combination with caloric restriction, our analyses showed no change in liver fat, or IMTG. Additional investigation is required to delve into the processes behind these findings and to pinpoint treatments that efficiently focus on reducing ectopic fat

Background: Childhood and adolescence are critical developmental periods during which dietary protein plays a crucial role in musculoskeletal health. While the significance of protein in muscle development is well acknowledged, the complex associations between dietary protein intake and musculoskeletal parameters during these stages remain incompletely elucidated.

Methods: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 cycles, including 3,455 children and adolescents aged 8-19 years. Dietary protein intake was assessed through two 24-hour dietary recalls. Appendicular lean mass index (ALMI) and combined grip strength were measured as indicators of musculoskeletal health. Multivariate linear regression models and smooth curve fitting techniques were employed to analyze associations.

Results: Higher protein intake was positively associated with both ALMI (β = 0.003, 95% CI: 0.002, 0.004, p < 0.001) and combined grip strength (β = 0.043, 95% CI: 0.027, 0.058, p < 0.001) in fully adjusted models. Notably, sex-specific effects were observed, with stronger associations in boys, particularly in the 8-11 years age group.

Conclusions: This study reveals significant positive associations between dietary protein intake and musculoskeletal health indicators in children and adolescents, with pronounced sex-specific effects. These findings underscore the importance of adequate protein intake during critical developmental periods and may inform targeted nutritional strategies for optimizing long-term musculoskeletal health.

Background: The effectiveness and practicality of time-restricted eating (TRE) when trying to maximize muscle mass and strength is unclear. Thus, we examined the effects of a hypercaloric 16:8 TRE approach during supervised progressive resistance exercise.

Methods: Seventeen healthy and well-trained men (n = 10) and women (n = 7) were randomly assigned to TRE or control (FED). Both groups consumed a 10% hypercaloric high-protein (2.2 g/kg/d) diet and performed supervised resistance exercise 4× per wk for 8 wk. TRE consumed all calories within an 8 h window starting at least 1 h post-exercise, while FED consumed the same number of calories throughout the day.

Results: Eating windows were significantly different (TRE: 7.9 ± 0.1 h vs. FED: 13.2 ± 0.6 h). Calorie, carbohydrate, fat, and protein intake did not differ statistically between groups. Total exercise volume was significantly lower in TRE than FED (6,960 ± 287 vs. 7,334 ± 289 repetitions), as were subjective daily energy ratings (week 4 = -1.41; p = 0.04, week 8 = -1.04; p = 0.06). Both groups increased maximal upper and lower body strength (1RM) and muscular endurance (ME); however, gains in squat 1RM were 4.0 ± 1.9 kg lower in TRE (p = 0.05). Both groups increased fat-free mass similarly (TRE: 2.67 kg; FED: 1.82 kg, p = 0.04), but FED added 1.4 ± 0.6 kg more fat mass (p = 0.04). Subjective mood and sleep ratings did not change in either group.

Conclusions: 16:8 TRE is viable during periods of muscle size, strength, and endurance development in well-trained young men and women when engaging in progressive resistance exercise and eating in a caloric surplus with adequate protein. However, the differences in total training volume, squat 1RM, fat mass accumulation, and energy are notable and practically relevant. These findings should be considered within the broader context of an individual's goals, lifestyle, preferences, and exercise demands.

Background: Existing literature indicates that spirulina supplementation can improve a variety of blood morphological parameters (such as hemoglobin) in healthy and clinical populations. Given the importance of hemoglobin for endurance exercise, particularly at altitude, this study aimed to investigate whether spirulina supplementation can improve blood morphological parameters in healthy cyclists and positively influence physiological variables when completing a lactate threshold test at simulated moderate altitude (2,500 m).

Methods: Twenty (18 male; 2 female) healthy participants (Mean  ±  SD; Age 37   ±   9 years, Stature 181   ±   6 cm, Mass 81   ±   9 kg, $\dot{V}$O_2max 51.8   ±   7.8 ml·kg-1·min-1) ingested 6 g/day of spirulina or placebo for 3-weeks in a double-blinded randomized counter-balanced cross-over design, then completed a lactate threshold test at simulated moderate altitude, with a 14-day washout period between trials.

Results: Following spirulina supplementation, heart rate at the lactate threshold was significantly lower in comparison to placebo supplementation (spirulina = 152   ±   11 b.min -1 vs. placebo = 155   ±   12 b.min -1, p < 0.05). No other physiological variables (Watts, RER, RPE, VO₂) were significantly different (p > 0.05) at the calculated threshold, or during the first four lower stages. Red Cell Distribution Width significantly increased following spirulina supplementation in comparison to placebo (spirulina = 13.3   ±   0.9 % vs. placebo = 12.5   ±   0.7 %, p < 0.05). Plateletcrit significantly decreased following spirulina supplementation (spirulina = 0.288   ±   0.032 vs. placebo = 0.293   ±   0.050, p < 0.05). No other blood morphological parameters changed (p > 0.05).

Conclusion: In conclusion, three weeks of spirulina supplementation at 6 g/day reduced heart rate during a lactate threshold test at a simulated moderate altitude (2,500 m), but did not produce additional physiological or hematological benefits.

Background and objective: Over the last two decades, bioelectrical impedance analysis (BIA) has gained popularity as a method for assessing body compartments in nutrition studies, sports medicine, and evaluating hydration levels, fat mass, and fat-free mass variations in both healthy and diseased individuals. This study aims to offer researchers an overview of the research trends in BIA.

Methods: The data was obtained from the Web of Science Core Collection database. Bibliometric analysis was conducted using a package of R software (Bibliometrix 4.0).

Results: A total of 9471 articles have been published over the past 20 years, with an average annual growth rate of 10.1%. The research field primarily focuses on nutrition and dietetics, followed urology and nephrology, endocrinology and metabolism, general and internal medicine, engineering, geriatrics and gerontology, sport sciences, cardiovascular system and cardiology, physiology and science and technology-other topics. The research hotspots of BIA over the past 20 years have transitioned from "water" to "fat," and subsequently to "sarcopenia." "Sarcopenia" and "phase angle" (PhA) have emerged as recent research hotspots in the field of BIA.

Conclusion: A total of 9471 articles have been published over the past 20 years, with an average annual growth rate of 10.1%. Nutrition and dietetics have consistently been the primary research areas in the field of BIA. "Sarcopenia" and "PhA" have emerged as recent research hotspots in the field of BIA. The application of BIA in clinical practice still holds significant untapped potential.

Background: CrossFit^Ⓡ sessions and competitions are characterized by high-intensity challenges that combine aerobic and anaerobic activities with short recovery periods. As a result, effective nutritional practices play a crucial role in optimizing performance and enhancing recovery. Therefore, nutritional practices are central to optimizing performance and accelerating recovery. This review aims to summarize current evidence on nutritional and ergogenic aid responses to CrossFit^Ⓡ practice.

Methods: The search was conducted in four electronic databases (PubMed, Web of Science, Scopus and SportDiscus). Gray literature was also extracted for studies exploring the nutritional habits of CrossFit^Ⓡ participants as well as the ingestion of ergogenic aids. In addition, a meta-analysis was conducted to examine the impacts of dietary habits and ergogenic aids on performance.

Results: Forty-nine studies met the eligibility criteria and were included in the current review. Carbohydrate intake was below the recommendations for athletes, although protein ingestion remains adequate. High-carbohydrate diets had a positive effect on CrossFit^Ⓡ performance. The evidence concerning the effects of a ketogenic diet on performance is limited. When used prior to or during the workout, the impact of carbohydrates on CrossFit^Ⓡ performance was negligible, whereas the effect of caffeine was significant. Ergogenic aids, particularly creatine and protein, are commonly used by CrossFit^Ⓡ participants.

Conclusion: The standard diets recommended to CrossFit^Ⓡ participants need to be revised because they are characterized by lower values of carbohydrates. Caffeine should be used prior to or during the CrossFit^Ⓡ sessions. Regarding the impact of ergogenic aids on recovery, future studies are needed.

Background: Rapid weight loss (RWL) is a common strategy among competitive powerlifters aiming to qualify for lower weight categories and improve competitive advantage. However, the effects of RWL followed by short-term recovery on maximal strength performance remain unclear. This study aimed to examine whether a ~ 5% RWL protocol followed by a 2-hour recovery period affects changes in maximal and relative strength performance in trained male powerlifters.

Methods: This randomized controlled trial (RCT) was registered in the Australian New Zealand Clinical Trials Registry (ACTRN12622000924752). In this RCT study, 26 male powerlifters (24.6 ± 4.5 y; 92.8 ± 13.6 kg) were assigned to a rapid weight loss (RWL; n = 13) or control group (CON; n = 13). RWL participants followed a 4-day protocol including caloric restriction (-10%), low carbohydrate intake ( <50 g/day), low sodium, and fluid manipulation, targeting a 5% body mass reduction. The CON group maintained habitual diet and hydration. Maximal strength was assessed via simulated powerlifting competition conducted before (C1) and after (C2) the intervention. Performance variables included squat (SQ), bench press (BP), deadlift (DL), and total load (TOTAL), along with IPF GL (International Powerlifting Federation GoodLift points) and IPF GL BP (International Powerlifting Federation GoodLift for Bench Press) scores. Body composition and rate of perceived exertion (RPE) were also evaluated.

Results: The RWL group achieved a mean body mass reduction of 4.81%, with significant decreases in fat mass (-15.7%), fat-free mass (-2.36%), and body water (-2.41%) compared to CON (all p < 0.01). Despite these changes, no significant differences in maximal strength (SQ, BP, DL, TOTAL) were observed between C1 and C2 or between groups. However, the RWL group showed a significant post-intervention increase in IPF GL (p = 0.015) and IPF GL BP scores (p = 0.017). RPE values showed no consistent or practically relevant changes.

Conclusion: In the group that underwent a rapid weight loss of approximately 5%, followed by a short-term recovery period, maximal strength performance was maintained. This indicates that it is possible to reduce body mass without compromising absolute strength levels in competitive powerlifters. At the same time, RWL group achieved higher IPF GL and IPF GL BP values.

Background: Caffeine (CAF) and taurine (TAU) have each demonstrated ergogenic effects across physical and cognitive domains. Often co-formulated in commercial energy drinks, they are widely regarded as the two principal bioactive compounds. However, findings regarding their combined efficacy remain inconclusive. This systematic review and Bayesian network meta-analysis aimed to quantify the individual and combined effects of CAF and TAU on physical capacity, cognitive function, and physiological responses, with a focus on identifying potential synergistic or antagonistic interactions.

Methods: Cochrane Library, PubMed, SciELO, SportsDiscus-EBSCO and Web of Science were searched through 25 July 2025. The pooled effect of each outcome was summarized using SMD (Hedge's g) by Bayesian arm-based multilevel network meta-analysis, and SUCRA ranking was applied to estimate the relative treatment effect.

Results: Twelve studies were included (8 on physical capacity, 7 on blood lactate (B[la]), and 6 each on cognitive function, heart rate (HR), and rating of perceived exertion (RPE)). Posterior estimates indicated that CAF+TAU was associated with a credible positive effect on anaerobic capacity (g = 0.46, 95% CrI [0.19, 0.71]) and reaction time (g = 0.75, 95% CrI [0.29, 1.18]) compared to CAF or TAU alone. CAF showed the greatest posterior reduction in RPE (g = -0.64, 95% CrI [-1.20, -0.10]), while its posterior mean estimate suggested a potential increase in B[la] (g = 0.24, 95% CrI [-0.48, 0.96]). In contrast, TAU showed a possible tendency toward reducing B[la] (g = -0.30, 95% CrI [-1.01, 0.42]). No credible differences in HR were observed across conditions. Effects on aerobic performance and physiological measures were variable and appeared to be context-dependent. SUCRA rankings consistently favored CAF+TAU across most outcome domains.

Conclusions: CAF+TAU co-supplementation provides a balanced ergogenic effect, combining the central stimulation of CAF with the neuromodulatory and metabolic support of TAU, particularly beneficial for high-intensity, reaction-based tasks. Its effects on endurance and physiological indices vary by condition, highlighting the need for personalized application.

Background: Creatine supplementation in women has gained attention for its potential benefits beyond muscle growth, including reproductive health, cognitive health and aging. Women exhibit distinct physiological differences from men, influenced by hormonal fluctuations during pre-menopause, pregnancy, and menopause, and these factors should be considered for their influence on creatine metabolism.

Objective: This review aims to provide a historical evaluation of creatine supplementation in women, its potential applications across female-specific life stages, recent research highlights, and targets for future research. The review also considers the impact of hormonal changes on creatine metabolism and effectiveness as a dietary supplementation.

Methods: This is a narrative overview of historical and recent research evaluating the effects of creatine in women.

Results: Early studies demonstrated the benefits of creatine on exercise performance in women, though they often overlooked menstrual cycle variability. Recent research has begun to account for these hormonal fluctuations, enhancing the understanding of creatine's applications. Creatine supplementation has shown positive effects on muscle strength, exercise performance, and body composition, particularly when combined with resistance training. Additionally, creatine may improve mood and cognitive function, potentially alleviating symptoms of depression. Emerging evidence suggests creatine's benefits during pregnancy and post-menopause, though data on perimenopausal women remains limited.

Conclusion: Creatine supplementation presents a promising strategy for enhancing various aspects of women's health across the lifespan. Future research should focus on optimizing dosing strategies, understanding long-term health implications, and exploring creatine's effects during pregnancy and perimenopause.

Background: Carbohydrate (CHO) mouth rinsing improves performance by stimulating oral receptors linked to brain regions involved in motor control and motivation, without requiring digestive processing. Most research has focused on fasting states, but the effects of postprandial CHO mouth rinsing remain inconclusive. This study aims to synthesize existing studies on the impact of postprandial CHO mouth rinsing on exercise and cognitive performance, offering insights for future research and practical recommendations for athletes and coaches.

Methods: Six databases (Pubmed, Web of Science, Cochrane Library, Embase, SciELO and SPORTDiscus) were searched up to March 2025 for randomized, placebo-controlled trials in healthy adults who performed exercise or cognitive tasks under fed conditions following CHO mouth rinsing. A three-level random-effects meta-analysis was performed for exercise performance, while narrative synthesis was applied for cognitive outcomes. For exercise performance, moderator and meta-regression analyses examined sex, training status, exercise modality, rinse composition and concentration, rinse duration, timing of food intake and pre-exercise dietary content.

Results: Thirty-five articles met inclusion criteria: two assessed cognitive performance and thirty-three evaluated exercise performance. Overall, CHO mouth rinsing improved cognitive function under fed conditions compared with placebo, though certainty was very low. Meta-analysis showed a small but significant ergogenic effect on exercise performance (Hedges' g = 0.18, 95% CI [0.09, 0.28], p < 0.01). Moderator and meta-regression analyses indicated that CHO mouth rinsing was more effective under fed conditions during aerobic exercise, when using maltodextrin solutions, rinsing for ≤10 s, and following a high-CHO meal.

Conclusions: This systematic review and three-level meta-analysis provides evidence that CHO mouth rinsing is ergogenic under fed conditions, improving both exercise and cognitive performance, though the overall certainty of evidence is low. Practical applications include its potential use as a simple, noninvasive ergogenic aid, particularly when combined with specific exercise modalities and nutritional strategies.