Jagim, Andrew R.

Carbohydrate availability and caffeine ingestion have been shown to elicit improvements in performance independently of one another. The purpose of the study was to examine the effect of a carbohydrate + caffeine beverage on performance and perceived effort in soccer players. Forty-three collegiate women’s soccer athletes were recruited to participate during a single day of simulated match play, in which each team played once. Athletes consumed either a carbohydrate + caffeine (Experimental) beverage or a control (Control) beverage (flavored water) during half-time in a double-blind, placebo-controlled, randomized control trial design. Prior to and after each game, Ratings of Perceived Exertion (RPE) and blood glucose levels were assessed. Heart rate, training impulse (TRIMP), total distance covered, high-speed distance, and velocity were recorded. Blood glucose levels after the match simulation were positively associated with total distance (r = 0.434; p = 0.01), distance per minute (r = 0.439; p < 0.01), average velocity (r = 0.438; p = 0.01), and TRIMP (r = 0.404; p = 0.018) during the second half. There was a significant main effect for half regarding blood glucose (p < 0.001), total distance (p < 0.001), high-speed distance (p < 0.001), and TRIMP (p = 0.046). There was a significant half × condition effect for blood glucose (p = 0.05). Pairwise comparisons indicated the Experimental beverage condition resulted in a +27 mg/dL (95% CI: −3.6, 58.8) difference compared to the Control beverage following the 2nd Half. In the current study, consumption of the carbohydrate + caffeine beverage during half-time resulted in higher blood glucose levels post-game compared to placebo; however, the experimental beverage did not influence the total distance covered, average velocities, average heart rate, or TRIMP values during the second half of simulated match play.

The purpose of this study was to examine the validity of a Garmin device for estimating heart rate, energy expenditure, and step count during incremental treadmill exercise. Eighteen physically active males (n = 12; mean ± SD age = 22.8 ± 4.7 years; body mass = 83.8 ± 13.4 kg) and females (n = 6; 24.2 ± 5.6 years; 65.2 ± 9.6 kg) completed an incremental treadmill test with the Garmin Vivoactive 4 and criterion methods measuring heart rate, energy expenditure, and step count. Mean absolute percent error (MAPE) and Bland–Altman plots were used to assess accuracy. Acceptable accuracy was defined as MAPE < 5% for heart rate and <10% for energy expenditure and step count. MAPE (±SD) values were 13.0 (±10.1), 19.1 (±15.0), and 4.6 (±5.3)% for heart rate, energy expenditure, and step count, respectively. The Bland–Altman regression analyses illustrated proportional bias was present for heart rate (r = 0.591, p < 0.001) and step count (r = 0.516, p = 0.028), but not energy expenditure (r = 0.351, p = 0.153). These findings indicated that the Garmin Vivoactive 4 provided acceptable accuracy for step count but unacceptable accuracy for heart rate and energy expenditure during incremental treadmill exercise.

Background/Objectives: Women’s wrestling is one of the fastest growing sports within the United States at the high school and collegiate level. Weight-class sports, such as wrestling, present unique challenges for female athletes, particularly in managing acute weight fluctuations associated with the menstrual cycle. However, less is known regarding how sex-specific physiology may influence weight management strategies among female wrestlers. The purpose of this review was to highlight current weight loss trends among high school and collegiate female wrestlers and summarize the physiological mechanisms driving potential menstrual-related fluid retention and subsequent changes in body mass or composition. Methods: A literature review was conducted to include studies evaluating weight loss trends in female wrestlers competing in the United States. Additional literature focused on fluid, body mass, and body composition changes throughout the menstrual cycle was also included. Results: Recent evidence has provided observational data that can be used to develop descriptive summaries of current body composition profiles and weight loss trends among female wrestlers. These data can help to quantify the typical magnitude of weight loss changes observed in female wrestlers competing at the high school and collegiate level within the United States. Conclusions: These findings help provide insight into the magnitude of weight loss wrestlers undergo in an effort to compete in their minimal weight class, thus informing practitioners of potential health risks and helping guide optimal weight management efforts.

Nutritional supplement use is common among athletes aiming to enhance performance, recovery, and health. However, variable regulatory frameworks and limited safety oversight create risks for inadvertent doping violations. This article provides a global overview of supplement use, relevant authorities, legislation, and safety measures, with a focus on third-party testing (TPT) as a risk-mitigation strategy. Data from six global regions—Africa, Asia, Australia/New Zealand, Europe, Latin America, and North America—were synthesized from peer-reviewed studies, governmental sources, and regional expert contributions. Reported supplement use ranged from 7% to 100% among athletes (variability within regions), with protein powders, vitamins/minerals, creatine, caffeine, and sports drinks being most prevalent. High-risk products (potential anti-doping rule violations), including certain herbal blends, preworkouts, and weight-management supplements, were reported across all regions. While some countries have robust regulatory systems, most lack harmonized or enforceable safety frameworks. TPT programs, which independently verify products for prohibited substances, remain concentrated in the global northwest (Europe, North America, and Australia/New Zealand); awareness and use of TPT certification vary widely, and even in regions with established systems, athlete adherence is inconsistent. Barriers to low-risk supplement use are limited TPT availability, cost, differences in labeling (including language), and cultural factors. Firsthand experiences and perceptions highlight widespread misconceptions about supplement safety and certification. The authors recommend expanded athlete and team-around-the-athlete education, improved global access to TPT low-risk supplements, and policy initiatives to harmonize safety standards. This work emphasizes the need for coordinated international efforts to protect athlete health and integrity while allowing access to evidence-based supplementation.

Abstract Jagim, AR, Dobbs, WC, Horswill, CA, Twohey, E, Fields, JB, and Jones, MT. Prevalence and magnitude weight loss among collegiate wrestlers. J Strength Cond Res 40(1): 90–97, 2026—The purpose of this study was to examine the percentage of wrestlers who compete in their minimal weight class (MWC), and the magnitude of weight loss. Data from the 2023–2024 collegiate season were retrospectively analyzed resulting in a sample of 9,638 collegiate male wrestlers from the National Association of Intercollegiate Athletics ( n = 1,904) and all 3 divisions of the National Collegiate Athletics Association ( n = 7,734). All wrestlers completed skinfold assessments for weight certification at the start of the competition season. The lowest recorded weight class (LRW) achieved by each wrestler during the season was also recorded and used to determine magnitude of weight loss. Out of the 4,605 (53.2%) of wrestlers who competed in their MWC, their average amount of weight loss was significantly higher than those who did not compete in their MWC (3.9 ± 2.5 vs. 3.2 ± 2.9 kg.; p < 0.001), yet they had an initial lower body fat percentage (12.7 ± 2.9 vs. 17.5 ± 4.8%; p < 0.001). At the time of weight certification, wrestlers weighed 8.1 ± 4.5 (95% confidence interval (CI): 8.0–8.2; effect size (ES) = 1.8) kg more than their minimal wrestling weight. The LRW was 3.6 ± 2.9 (95% CI: 3.6–3.7; ES = 1.2) kg lower than their weight at the time of weight certification. Given that slightly more than half of the male wrestlers competed in their MWC, coaches and sports practitioners should recognize that not all athletes follow the traditional assumption of cutting to the lowest possible weight class. Importantly, those who did achieve their MWC had lower initial body fat percentages, limiting the amount of weight they could safely lose. This underscores the need for individualized weight management strategies that consider body composition and health implications.

Background: Differences in total daily energy expenditure (TDEE) across sports, sex, and skill level support the need for sport- and athlete-specific energy intake recommendations. The purpose of the current review was to examine TDEE and related markers of energy expenditure across field-based team sports. A secondary aim was to evaluate physical activity levels (PAL), calculated as TDEE divided by resting metabolic rate (RMR), and their utility in estimating energy needs within team sports. Methods: The review was limited to studies that included the field-based team sports of rugby or soccer and reported energy expenditure data using doubly labeled water (DLW). A literature review identified 11 studies meeting criteria. Weighted means (Xw) and standard deviations (SDw) were calculated for each variable when pooled across each sport category. Results: Rugby (4417 ± 654 kcal·d−1) had a higher average TDEE than soccer (3157 ± 331 kcal/day; p < 0.001). When normalized to body mass, rTDEE was similar between sports (rugby: 49.5 ± 1.3 kcal·kg−1·day−1; soccer: 49.3 ± 1.8 kcal·kg−1·day−1; p = 0.967). PAL values were significantly higher in rugby (2.2 ± 0.4) compared to soccer (1.7 ± 0.2; p = 0.004). RMR was also greater in rugby (2136 ± 322 kcal·d−1) compared to soccer (1835 ± 208 kcal·d−1; p = 0.04). Conclusions: Rugby athletes exhibited higher TDEE values than soccer athletes, reflecting greater absolute energy demands. However, similar relative TDEE values suggest that differences in body size and composition likely contribute to the observed differences in absolute expenditure. These findings underscore the importance of individualized nutrition strategies within team sports and highlight PAL as a useful metric to contextualize energy requirements.

Abstract Fields, JB, Jones, MT, Kitts, SE, King, EL, and Jagim, AR. Relationships between disordered eating, body dissatisfaction, and low energy availability in women collegiate athletes. J Strength Cond Res 40(2): e164–e171, 2026—Women collegiate student-athletes face unique challenges regarding nutrition, body image, and athletic performance, increasing their risk for low energy availability (LEA), disordered eating (DE), and body dissatisfaction (BID). However, limited data exist exploring LEA, DE, and BID across a variety of women's sports. Therefore, the purpose of this study was to evaluate the prevalence of and relationships among LEA risk, DE behaviors, and BID in women collegiate athletes from multiple sports. Division I, II, and III women student-athletes ( n = 115) participated in this cross-sectional, descriptive study. Athletes completed the low energy availability for females questionnaire (LEAF-Q), eating attitudes test (EAT-26), muscularity-oriented eating test (MOET), and body dissatisfaction items from the eating disorder examination questionnaire (EDE-Q) to assess LEA risk, DE behaviors, and BID, respectively. Sixty-four percentages of athletes were at risk for LEA, with the highest prevalence in volleyball (100%), wrestling (68%), lacrosse (67%), and cross country (57%). However, only 8% of athletes were classified at risk for eating disorders. Notably, 81 and 84% of athletes reported body weight and shape dissatisfaction, respectively, which was strongly associated with disordered eating behaviors (EAT-26: r = 0.707; MOET: r = 0.723, p < 0.001). These results show a high prevalence of LEA risk and BID across athletes, with DE behaviors strongly linked to body image concerns. Despite a high LEA risk among athletes, clinical eating disorder risk remained low, suggesting that undereating may often be unintentional. Targeted interventions focused on nutritional education, body image, and psychological support are critical for improving health and performance outcomes among collegiate women student-athletes.

Objective We examined the weight management practices of successful high school wrestlers to contribute meaningful data to the conversations that weight-certifying clinicians and athletic trainers have with athletes at the start of the wrestling season. Understanding how elite athletes navigate weight management can inform safer and more individualized guidance during preseason assessments. Specifically, we sought to determine the proportion of state-qualifying wrestlers who competed at or above their certified minimum weight class. We also quantified the magnitude of weight change from certification to state competition and analyzed seasonal trends in both body weight and body fat percentage over a 20-year period. Design Longitudinal retrospective review. Setting Four Minnesota high schools. Patients or Other Participants State-qualifying wrestlers from 2003 to 2023. Independent Variable State-qualifying weight class. Main Outcome Measure(s) Dependent variables are certification weight, measured body fat percent, and calculated minimum weight class. Results Only 48 wrestlers (52.7%; CI = 42.5%, 63.0%) competed at state in their minimum weight class, while the other 43 competed 1 to 2 weight classes above. Thirty-six wrestlers (39.6%) gained weight over the season. Conclusions Nearly half the successful wrestlers competed in weight classes above their minimum weight, while 5% lost 9% to 18% of their body mass over the wrestling season. This suggests factors other than maximizing individual athletic potential, such as team needs to fill a weight class, influence weight management decisions. Over the 20-year span of the study, trends toward lower measured body fat percentage and lower weight fluctuations suggest influences from sports specialization and year-round training and less emphasis on extreme leanness for competitive advantage. Athletes, in consultation with their coaches and clinicians, should select a competition weight class where they can adequately fuel, train, and recover. This may not be their minimum certified weight class.

Abstract Twohey, E, Dobbs, WC, Malone, CM, Fields, JB, Jones, MT, and Jagim, AR. The use of a consumer-grade bioelectrical impedance analysis device for weight certification in collegiate wrestling: Implications for minimal wrestling weight determination. J Strength Cond Res 39(12): 1321–1326, 2025—Wrestlers are required to complete a preseason weight certification assessment, which includes a weigh-in, a hydration test, and a body fat percentage (BF%) measurement. This information is then used to establish their minimal wrestling weight (MWW) and minimal weight class. Skinfold (SKF) is the primary method used for determining body fat for collegiate wrestling, yet impedance devices are being considered for use in the future. The purpose of this study was to examine differences in body fat and the resulting MWW values derived from SKF and a consumer-grade multifrequency bioelectrical impedance analysis (MFBIA) device. Thirty-one collegiate male wrestlers produced a urine sample for urine specific gravity assessment to ensure adequate hydration status. Subjects then completed a weigh-in, followed by 2 body composition assessments using a (a) MFBIA device and (b) skinfold calipers to determine body density and BF%. No significant differences were observed for estimates of BF% (SKF: 13.4 ± 2.8% vs. MFBIA: 14.0 ± 3.3%; p = 0.198) or computed MWW values (SKF: 69.8 ± 8.7 kg vs. MFBIA: 69.4 ± 9.7 kg; p = 0.348) between devices. When determining the minimal weight class for each device, there were discrepancies in 11 of the 31 wrestlers (35%). Although the current MFBIA device can provide an acceptable estimate of BF% and similar resulting MWW value at the group level, the methods cannot be used interchangeably.

The primary purpose of this study was to examine the acute effects of a multi-ingredient preworkout supplement (MIPS) on isometric, concentric, and eccentric peak torque and electromyographic (EMG) responses of the leg extensors during a fatiguing isokinetic protocol. Thirteen male subjects (mean age ± SD = 22.9 ± 2.2 years) were assigned in crossover fashion to ingest an MIPS or placebo before an isokinetic protocol that consisted of 30 maximal, concentric and eccentric muscle actions with EMG signals recorded from the vastus lateralis, rectus femoris, and vastus medialis muscles. Immediately before (PRE) and after (POST) the isokinetic fatigue protocol, subjects were assessed for isometric peak torque. The MIPS condition resulted in greater isometric (205 ± 48 vs. 185 ± 44 N·m, p = 0.04) and concentric (121 ± 34 vs. 103 ± 27 N·m, p = 0.015) torque values versus placebo (collapsed across time). For eccentric peak torque as well as EMG amplitude and frequency values, there were no significant (p > 0.05) interactions or main effects for each condition. These findings indicated that acute ingestion of the MIPS enhanced isometric and concentric peak torque of the leg extensors, which was not explained by changes in the EMG signal.