Browsing by Author "Tinsley, Grant M. (TTU)"
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Item ADORA2A C Allele Carriers Exhibit Ergogenic Responses to Caffeine Supplementation(2020) Grgic, Jozo; Pickering, Craig; Bishop, David J.; Coso, Juan Del; Schoenfeld, Brad J.; Tinsley, Grant M. (TTU); Pedisic, ZeljkoCaffeine’s ergogenic effects on exercise performance are generally explained by its ability to bind to adenosine receptors. ADORA2A is the gene that encodes A2A subtypes of adenosine receptors. It has been suggested that ADORA2A gene polymorphisms may be responsible for the inter-individual variations in the effects of caffeine on exercise performance. In the only study that explored the influence of variation in ADORA2A—in this case, a common polymorphism (rs5751876)—on the ergogenic effects of caffeine on exercise performance, C allele carriers were identified as “non-responders” to caffeine. To explore if C allele carriers are true “non-responders” to the ergogenic effects of caffeine, in this randomized, double-blind study, we examined the acute effects of caffeine ingestion among a sample consisting exclusively of ADORA2A C allele carriers. Twenty resistance-trained men identified as ADORA2A C allele carriers (CC/CT genotype) were tested on two occasions, following the ingestion of caffeine (3 mg/kg) and a placebo. Exercise performance was evaluated with movement velocity, power output, and muscle endurance during the bench press exercise, countermovement jump height, and power output during a Wingate test. Out of the 25 analyzed variables, caffeine was ergogenic in 21 (effect size range: 0.14 to 0.96). In conclusion, ADORA2A (rs5751876) C allele carriers exhibited ergogenic responses to caffeine ingestion, with the magnitude of improvements similar to what was previously reported in the literature among samples that were not genotype-specific. Therefore, individuals with the CT/CC genotype may still consider supplementing with caffeine for acute improvements in performance.Item Caffeine Timing Improves Lower-Body Muscular Performance: A Randomized Trial(2020) Harty, Patrick S. (TTU); Zabriskie, Hannah A.; Stecker, Richard A.; Currier, Brad S.; Tinsley, Grant M. (TTU); Surowiec, Kazimierz (TTU); Jagim, Andrew R.; Richmond, Scott R.; Kerksick, Chad M.Little is known about the optimal time to consume caffeine prior to exercise to maximize the ergogenic benefits of the substance. Purpose: To determine the optimal pre-exercise time interval to consume caffeine to improve lower-body muscular performance. A secondary aim was to identify the presence of any sex differences in responses to timed caffeine administration. Methods: Healthy, resistance-trained males (n = 18; Mean±SD; Age: 25.1 ± 5.7 years; Height: 178.4 ± 7.1 cm; Body mass: 91.3 ± 13.5 kg; Percent body fat: 20.7 ± 5.2; Average caffeine consumption: 146.6 ± 100.3 mg/day) and females (n = 11; Mean ± SD; Age: 20.1 ± 1.6 years; Height: 165.0 ± 8.8 cm; Body mass: 65.8 ± 10.0 kg; Percent bodyfat: 25.8 ± 4.2; Average caffeine consumption: 111.8 ± 91.7 mg/day) participated in this investigation. In a randomized, double-blind, placebo-controlled, crossover fashion, participants consumed 6 mg·kg−1 caffeine or placebo solution at three time points: 2 h prior (2H), 1 h prior (1H), or 30 min prior (30M) to exercise testing. During three visits, caffeine was randomly administered at one time point, and placebo was administered at the other two time points. During one visit, placebo was administered at all three time points. Next, participants performed isometric mid-thigh pulls (IMTP), countermovement vertical jumps (CMVJ), and isometric/isokinetic knee extensor testing (ISO/ISOK). Results: Caffeine administered at 1H significantly improved absolute CMVJ and ISO performance relative to placebo. Mean CMVJ jump height was significantly higher during 1H compared to 30M. However, only caffeine administered at 30M significantly improved absolute measures of isokinetic performance. Analysis of the pooled caffeine conditions revealed that muscular performance was more consistently augmented by caffeine in males compared to females. Conclusions: Pre-exercise caffeine timing significantly modulated participant responses to the substance, with 1H exerting the most consistent ergogenic benefits relative to other time points, particularly compared to 2H. Male participants were found to respond more consistently to caffeine compared to female participants. These results suggest that active individuals can maximize the ergogenic effects of caffeine by consuming the substance ~1 h prior to the point when peak muscular performance is desired.Item Can Bodybuilding Peak Week Manipulations Favorably Affect Muscle Size, Subcutaneous Thickness, and Related Body Composition Variables? A Case Study(2022) Barakat, Christopher; Escalante, Guillermo; Stevenson, Scott W.; Bradshaw, Joshua T.; Barsuhn, Andrew; Tinsley, Grant M. (TTU); Walters, JosephBackground: The purpose of this case study was to implement an evidence‐based dietary approach to peaking for a bodybuilding competition and monitor its impact on body composition, muscle thickness (MT), intra‐to‐extra‐cellular fluid shifts, subcutaneous thickness (ST), and hydration status. Secondarily, to document any adverse events of this peak week approach in a small, controlled setting. Methods Dietary practices were recorded, and laboratory testing was conducted throughout peak week, including competition morning. Assessments included: dual‐energy X‐ray absorptiometry (DEXA) for body composition, B‐mode ultrasound for MT and ST, bioimpedance spectroscopy (BIS) for total body water (TBW)/intracellular water (ICW)/extracellular water (ECW), and raw BIS data (i.e., resistance, reactance, and phase angle), urine specific gravity (USG) for hydration status, and subjective fullness. Sequential dietary manipulations were made (i.e., CHO depletion/fat loading, CHO/water loading, and a refinement phase) with specific physiological goals. This was reflected in changes observed across all assessments throughout the peak week. Results: From the carbohydrate‐depleted state (three days out) to competition day, we observed increases in lean body mass, MT, TBW (primarily ICW), and subjective fullness. Kendall’s Tau B revealed a strong relationship between carbohydrate intake and ∑MT (τ = 0.733, p = 0.056). Additionally, novel ST data demonstrated a 10% reduction for the summation of all seven sites, with some drastic changes in specific regions (e.g., −43% for triceps ST) from three days out to competition day. Conclusions: These data suggest that the prototypical goals of bodybuilders’ peak week (i.e., increasing muscle fullness, decreasing subcutaneous thickness) to enhance their aesthetics/muscularity presented can be achieved with a drug‐free protocol involving dietary manipulations.Item Changes in total and segmental bioelectrical resistance are correlated with whole-body and segmental changes in lean soft tissue following a resistance training intervention(2019) Tinsley, Grant M. (TTU); Harty, Patrick S. (TTU); Moore, M. Lane (TTU); Grgic, Jozo; Silva, Analiza M.; Sardinha, Luis B.Background: Raw bioelectrical values can be used to assess physiological outcomes, though limited information is available concerning the relationships between changes in these values and changes in other variables of interest. Methods: This investigation quantified the relationships between total and segmental changes in raw bioelectrical variables (i.e., resistance, reactance, and phase angle) and corresponding whole-body and segmental changes in independently assessed body composition. Resistance-trained females (n = 31, body mass index: 22.8 ± 2.6 kg/m2, body fat: 28 ± 6%) completed eight weeks of supervised resistance training. Before and after the intervention, body composition was assessed via dual-energy X-ray absorptiometry (GE® Lunar Prodigy), and raw bioelectrical variables were assessed via 8-point multi-frequency bioelectrical impedance analysis (Seca® mBCA 515/514) at 19 frequencies ranging from 1 to 1000 kHz. Results: Lean soft tissue of the whole body (+ 3.2% [2.1, 4.4]; mean [95% confidence interval]) and each body segment (+ 2.8 to 6.3%) increased as a result of the intervention. Group-level changes in total (-2.4% [-5.2, 0.3]) and segmental fat mass were not statistically significant. Significant decreases in total resistance (-2.1% [-3.7,-0.6] at 50 kHz) and increases in phase angle (+ 4.2% [2.5, 5.9] at 50 kHz) were observed, with minimal changes in reactance and varying changes in segmental values. Moderate to strong negative correlations (0.63 ≤ |r| ≤ 0.83, p ≤ 0.001) were found between changes in lean soft tissue and changes in resistance for the whole body, trunk, and arms. No significant correlations were identified between changes in fat mass or bone mineral content and changes in any bioelectrical variable. Conclusions: Total and segmental changes in resistance were associated with corresponding total and segmental changes in lean soft tissue following a resistance training intervention, while fewer associations were identified between changes in other bioelectrical parameters (i.e., reactance and phase angle) and body composition variables (e.g., fat mass and bone mineral content). Measurement frequency and body segment appeared to influence the presence and strength relationships between bioelectrical and body composition variables. These findings suggest that researchers and practitioners utilizing bioimpedance technology may benefit from examining raw resistance values to enhance detection of physiological adaptations to exercise interventions.Item Chronic Thermogenic Dietary Supplement Consumption: Effects on Body Composition, Anthropometrics, and Metabolism(2023) Siedler, Madelin R. (TTU); Rodriguez, Christian (TTU); White, Sarah J. (TTU); Tinoco, Ethan (TTU); DeHaven, Brielle (TTU); Brojanac, Alexandra (TTU); LaValle, Christian (TTU); Rasco, Jaylynn (TTU); Taylor, Lem W.; Tinsley, Grant M. (TTU)Multi-ingredient thermogenic supplements can acutely increase resting energy expenditure (REE) and subjective energy. However, less is understood about the effects of chronic consumption on body composition, metabolism, and subjective variables such as mood, sleep quality, and eating behaviors. Fifty-two healthy, exercise-trained participants (50% female; mean ± SD age: 23.5 ± 3.0 years; body fat percentage: 27.3 ± 8.0%) were randomized 2:2:1 to take a whey protein supplement alone (PRO; n = 20), in combination with a thermogenic supplement (PRO + FB; n = 19), or no supplement at all (CON; n = 13) for four weeks. Body composition, anthropometric, metabolic, hemodynamic, and subjective outcomes were collected before and after the intervention. Greater changes in REE occurred in PRO + FB as compared to CON (111.2 kcal/d, 95% CI 2.4 to 219.9 kcal/d, p = 0.04), without significant differences between PRO and CON (42.7 kcal/d, 95% CI −65.0 to 150.3 kcal/d, p = 0.61) or between PRO + FB and PRO (68.5 kcal/d, 95% CI −28.3, 165.3, p = 0.21). No changes in hemodynamic outcomes (blood pressure and heart rate) were observed. In exercising adults, four weeks of supplementation with protein and a multi-ingredient thermogenic product maintained fasted REE as compared to no supplementation, for which a decrease in REE was observed, without differential effects on body composition, anthropometrics, or subjective variables.Item Collegiate women’s wrestling body fat percentage and minimum wrestling weight values: time for revisiting minimal body fat percent?(2024) Jagim, Andrew R.; Tinsley, Grant M. (TTU); Oppliger, Robert A.; Horswill, Craig A.; Dobbs, Ward C.; Fields, Jennifer B.; Cushard, Cliff; Rademacher, Paul D.; Jones, Margaret T.Background: The estimation of body fat percentage (BF%) in wrestling is used to determine the minimum wrestling weight (MWW) and lowest allowable weight class (MWC) in which wrestlers are eligible to compete. A 12% minimum threshold is currently used for women wrestlers, yet a potential increase for safety has been discussed. Because of the novelty of collegiate women’s wrestling, there is a paucity of literature available on the body composition norms of this population. The purpose of this study was to provide a descriptive summary of BF% and MWW values of female wrestlers and how MWW values would change with the use of different BF% thresholds. Methods: Data from the 2022–2023 collegiate season were retrospectively analyzed resulting in a sample of 1,683 collegiate women wrestlers from the National Association of Intercollegiate Athletics (NAIA, n = 868) and the National Collegiate Athletics Association (NCAA, n = 815). All wrestlers completed skinfold assessments for weight certification at the start of the competition season. The skinfold values were used to estimate BF% using the Slaughter skinfold prediction equation. Frequency statistics and descriptive analysis were performed to compute normative MWW and BF% profiles. BF% thresholds of 12% (12MWW) and the BF% value defined as the lowest 5th percentile, which would be considered unusually lean, were used to determine the resulting MWW and MWC for each method. The lowest recorded weight and weight class division throughout the season was also recorded for each wrestler. Results: There was a positively skewed (0.94) and platykurtic (1.86) distribution of MWW values. The median ± interquartile range BF% for all wrestlers was 27.4 ± 10.22%, with 17% BF representing the 5th percentile. Only 354 out of 1,579 (22.4%) wrestlers competed in their lowest allowable weight class, based on the 12MWW. Of these 354 wrestlers, the mean BF% was 21.3 ± 5.2% at weight certification with only n = 17 being at or below 12% body fat and an average weight loss of 11.1 ± 8.8 lbs. from the time of weight certification. Throughout the season, wrestlers competed at weights that were, on average (mean ± SD), 19.4 ± 16.9 lbs. higher than their 12MWW (95% CI: 18.6, 20.2 lbs. p < 0.001; effect size [ES] = 1.1), 13.4 ± 19.0 lbs. higher than the 17MWW (p < 0.001; ES = 0.70), and 8.7 ± 8.3 lbs. lower than their weight at the certification (95% CI: 8.3, 9.1 lbs. p < 0.001; ES = 1.1). Conclusions: Nearly all BF% values were well above the 12% threshold used to determine MWW. Increasing the minimum BF% threshold from 12% to 17% would affect a small percentage of wrestlers, likely reduce the need for excessive weight cutting, and minimize the deleterious health effects of an athlete at such a low BF%.Item Comparison of High-Protein, Intermittent Fasting Low-Calorie Diet and Heart Healthy Diet for Vascular Health of the Obese(2016) Zuo, Li; He, Feng; Tinsley, Grant M. (TTU); Pannell, Benjamin K.; Ward, Emery; Arciero, Paul J.Aim: It has been debated whether different diets are more or less effective in long-term weight loss success and cardiovascular disease prevention among men and women. To further explore these questions, the present study evaluated the combined effects of a high-protein, intermittent fasting, low-calorie diet plan compared with a heart healthy diet plan during weight loss, and weight loss maintenance on blood lipids and vascular compliance of obese individuals. Methods: The experiment involved 40 obese adults (men, n = 21; women, n = 19) and was divided into two phases: (a) 12-week high-protein, intermittent fasting, low-calorie weight loss diet comparing men and women (Phase 1) and (b) a 1-year weight maintenance phase comparing high-protein, intermittent fasting with a heart healthy diet (Phase 2). Body weight, body mass index (BMI), blood lipids, and arterial compliance outcomes were assessed at weeks 1 (baseline control), 12 (weight loss), and 64 (12 + 52 week; weight loss maintenance). Results: At the end of weight loss intervention, concomitant reductions in body weight, BMI and blood lipids were observed, as well as enhanced arterial compliance. No sex-specific differences in responses were observed. During phase 2, the high-protein, intermittent fasting group demonstrated a trend for less regain in BMI, low-density lipoprotein (LDL), and aortic pulse wave velocity than the heart healthy group. Conclusion: Our results suggest that a high-protein, intermittent fasting and low-calorie diet is associated with similar reductions in BMI and blood lipids in obese men and women. This diet also demonstrated an advantage in minimizing weight regain as well as enhancing arterial compliance as compared to a heart healthy diet after 1 year.Item Effects of two pre-workout supplements on concentric and eccentric force production during lower body resistance exercise in males and females: A counterbalanced, double-blind, placebo-controlled trial(2017) Tinsley, Grant M. (TTU); Hamm, Matthew A. (TTU); Hurtado, Amy K. (TTU); Cross, Austin G. (TTU); Pineda, Jose G. (TTU); Martin, Austin Y. (TTU); Uribe, Victor A. (TTU); Palmer, Ty B. (TTU)Background: Pre-workout supplements purportedly enhance feelings of energy, reduce fatigue and improve exercise performance. The purpose of this study was to examine the performance effects of caffeinated and non-caffeinated multi-ingredient pre-workout supplements. Methods: In a counterbalanced, double-blind, placebo-controlled design, eccentric and concentric force production during lower body resistance exercise on a mechanized squat device were assessed after supplement ingestion. Repetitions-in-reserve/RPE and subjective feelings of energy, focus and fatigue were also examined. Twenty-one resistance-trained adults (12 F, 9 M) completed three conditions in random order: caffeinated supplement, non-caffeinated supplement and placebo. Subjects were not informed of the presence of a placebo condition. Thirty minutes after supplement ingestion, a 3-repetition maximum test and 5 sets of 6 repetitions were completed using the squat device. Each repetition involved 4-s eccentric and concentric phases, and the force signal throughout each repetition was sampled from a load cell contained within the squat device. The scaled and filtered force signals were analyzed using customized software. Repeated measures analysis of variance and appropriate follow-up analyses were utilized to compare dependent variables, and relevant effect sizes (d) were calculated. Results: Supplement or placebo ingestion led to similar subjective responses (p > 0.05). Energy (+8 to 44%; d = 0.3 to 0.8) and focus (+8 to 25%; d = 0.3 to 0.5) were acutely increased by supplement or placebo ingestion and decreased as the exercise session progressed. Fatigue was acutely decreased by supplement or placebo ingestion (-7 to 38%; d = -0.1 to -0.6) and increased as the exercise session progressed. Eccentric and concentric forces were unimproved by supplementation during the exercise sets for both sexes. In the non-caffeinated supplement condition only, maximal eccentric force production was lower during sets 3 to 5, as compared to set 1 (p < 0.05). Effect size data indicated that both the caffeinated and non-caffeinated supplements may contribute to small increases in concentric force production in males (+5 to 20%, d = 0.2 to 0.4 relative to placebo), but not females. Conclusions: As compared to placebo, caffeinated and non-caffeinated multi-ingredient pre-workout supplements failed to improve concentric and eccentric force production. In males, effect size data indicate a possible small benefit of supplementation on concentric force production, although this was not statistically significant. When resistance-trained subjects were unaware of the presence of a placebo, resistance exercise performance was similar regardless of whether a placebo or multi-ingredient supplement was ingested.Item Evaluation of novel beverage formulations for hydration enhancement in humans(2023) Tinsley, Grant M. (TTU); Siedler, Madelin R. (TTU); Rodriguez, Christian (TTU); Harty, Patrick S. (TTU); Stratton, Matthew T. (TTU); White, Sarah J. (TTU); Keith, Dale S. (TTU); Green, Jacob J. (TTU); Boykin, Jake R. (TTU); Williams, Abegale D. (TTU); DeHaven, Brielle (TTU); Brojanac, Alexandra (TTU); Tinoco, Ethan (TTU)This study evaluated the influence of novel beverage formulations on bioimpedance- and urine-based hydration markers. Thirty young healthy adults (n=16 females, n=14 males; age: 23.2±3.7 years; BMI: 24.3±3.3 kg/m2) participated in a randomized, double-blind, placebo-controlled, crossover study. Participants completed three conditions with baseline bioimpedance, urine, and body mass assessments, followed by ingestion of one liter of a test beverage over a 30-minute period. The three beverages were: active hydration formulation in still (AFstill) or sparkling (AFspark) water and a still water control. The active formulations were identical in concentrations of alpha-cyclodextrin and complexing agents. Following beverage ingestion, bioimpedance assessments were performed every 15 minutes for two hours, followed by final urinary and body mass assessments. The primary bioimpedance outcomes were phase angle at 50 kHz, resistance of the extracellular compartment (R0), and resistance of the intracellular compartment (Ri). Data were analyzed using linear mixed effects models, Friedman tests, and Wilcoxon tests. Statistically significant changes in phase angle values were observed at 30 (p=0.004) and 45 minutes (p=0.024) following the initiation of beverage ingestion in the AFstill condition as compared to the reference model (i.e., control condition at baseline). Although differences between conditions were not statistically significant at later time points, the data were consistent with AFstill having greater elevations in phase angle throughout the monitoring period. At the 30-minute time point only, statistically significant differences in R0 for AFspark (p<0.001) and in Ri for AFstill (p=0.008) were observed. When averaged across post-ingestion time points, there was a trend (p=0.08) for Ri differences between conditions. The net fluid balance was greater than zero, indicating retention of ingested fluid, for AFstill (p=0.02) and control (p=0.03), with a trend for AFspark (p=0.06). In conclusion, an active formulation containing alpha-cyclodextrin in still water demonstrated potential benefits for enhancing hydration markers in humans.Item Four weeks of time-restricted feeding combined with resistance training does not differentially influence measures of body composition, muscle performance, resting energy expenditure, and blood biomarkers(2020) Stratton, Matthew T. (TTU); Tinsley, Grant M. (TTU); Alesi, Michaela G.; Hester, Garrett M.; Olmos, Alex A.; Serafini, Paul R.; Modjeski, Andrew S.; Mangine, Gerald T.; King, Kelsey; Savage, Shelby N.; Webb, Austin T.; Vandusseldorp, Trisha A.Recently, interest in time-restricted feeding (TRF) has increased from reports highlighting improvements in body composition and muscular performance measures. Twenty-six recreationally active males were randomly assigned to either TRF (n = 13; ~22.9 years; 82.0 kg; 178.1 cm; 8 h eating window, 25% caloric deficit, 1.8 g/kg/day protein) or normal diet (ND; n = 13; ~22.5 years; 83.3 kg; 177.5 cm; normal meal pattern; 25% caloric deficit, 1.8 g/kg/day protein) groups. Participants underwent 4-weeks of supervised full body resistance training. Changes in body composition (fat mass (FM), fat free mass (FFM), and body fat percentage (BF%)), skeletal muscle cross sectional area (CSA) and muscle thickness (MT) of the vastus lateralis (VL), rectus femoris, (RF), and biceps brachii (BB) muscles, resting energy expenditure (REE), muscular performance, blood biomarkers, and psychometric parameters were assessed. Significant (p < 0.05) decreases were noted in BM, FM, BF%, testosterone, adiponectin, and REE, along with significant increases in BP1RM, LP1RM, VJHT, VJPP, VLCSA, BBCSA, and BBMT in both groups. Plasma cortisol levels were significantly elevated at post (p = 0.018) only in ND. Additionally, FFM was maintained equally between groups. Thus, a TRF style of eating does not enhance reductions in FM over caloric restriction alone during a 4-week hypocaloric diet.Item Glycoprotein Matrix Zinc Exhibits Improved Absorption: A Randomized Crossover Trial(2024) Jäger, Ralf; Purpura, Martin; Davis, Jaci; Keratsopoulos, Nikolas; Parra, Mandy E.; Secrest, Ariane H.; Tinsley, Grant M. (TTU); Taylor, LemBiotransformation of minerals via glycosylation by microorganisms such as yeast and/or probiotics yields nutrients bound to a food matrix, resulting in increased bioavailability. The purpose of this study was to compare the effects of glycoprotein matrix-bound zinc (GPM) on absorption compared to inorganic zinc oxide. Sixteen participants ingested 11 mg of zinc as either GPM™ Soy-Free Zinc (GPM, Ashland, Kearny, NJ, USA) or zinc oxide (USP). Blood samples were taken at 0 (i.e., baseline), 30, 60, 90, 120, 180, 240, 300, 360, 420, and 480 min post-ingestion. GPM zinc concentrations were significantly higher at 120 min (p = 0.02; 12.4 ± 5.1 mcg/dL), 180 min (p = 0.002; 16.8 ± 5.1 mcg/dL), and 240 min (p = 0.007; 14.6 ± 5.1 mcg/dL) in comparison to USP zinc oxide. In addition, GPM zinc significantly increased iAUC by 40% (5840 ± 2684 vs. 4183 ± 1132 mcg/dL * 480 min, p = 0.02), and Cmax values were 10% higher in GPM compared to USP (148 ± 21 mcg/dL vs. 135 ± 17.5 mcg/dL, p = 0.08). Tmax was 12% slower in GPM compared to USP (112.5 ± 38.7 min vs. 127.5 ± 43.1 min); however, differences in Tmax failed to reach statistical significance (p = 0.28). Zinc bound to a glycoprotein matrix significantly increased absorption compared to zinc oxide.Item Improved precision of 3-dimensional optical imaging for anthropometric measurement using non-rigid avatar reconstruction and parameterized body model fitting(2023) Tinsley, Grant M. (TTU); Harty, Patrick S. (TTU); Siedler, Madelin R. (TTU); Stratton, Matthew T. (TTU); Rodriguez, Christian (TTU)Background: Three-dimensional optical imaging for digital anthropometry and body composition estimation is increasingly available to health professionals and individual consumers. The purpose of the present analysis was to examine the precision of a scanner that employs non-rigid avatar reconstruction and parameterized body model fitting. Methods: Sixty-nine healthy adults (37 F, 32 M; [mean ±SD] age: 24.1±5.5 y; height: 169.2±13.9 cm; BMI: 26.0±5.2 kg/m2) were evaluated through duplicate scans using a second-generation prototype three-dimensional optical scanner. Test-retest precision was established using the intraclass correlation coefficient (ICC), root-mean-square coefficient of variation (RMS-%CV), precision error (PE), and least significant change. Results: Across 21 non-ankle body circumferences, PE ranged from 0.4 to 0.8 cm, RMS-%CV ranged from 0.4 to 1.4%, and ICC values were 0.975–0.999. Compared to the first-generation scanner (PE: 0.8–1.0 cm; RMS-%CV: 0.8–1.2%), the errors of waist and hip circumferences were reduced by half (PE: 0.4–0.5 cm, RMS-%CV: 0.4–0.6%). Estimated body fat percentage also demonstrated very high reliability (PE: 0.2%, RMS-%CV: 0.7%, ICC: 0.999). Conclusions: These findings support the improved precision of a second-generation scanner reconstructing a non-rigid avatar subject and parameterized body model fitting and demonstrate the low measurement error that is achievable with this technology.Item The Influence of Energy Balance and Availability on Resting Metabolic Rate: Implications for Assessment and Future Research Directions(2023) Siedler, Madelin R. (TTU); De Souza, Mary Jane; Albracht-Schulte, Kembra (TTU); Sekiguchi, Yasuki (TTU); Tinsley, Grant M. (TTU)Resting metabolic rate (RMR) is a significant contributor to an individual’s total energy expenditure. As such, RMR plays an important role in body weight regulation across populations ranging from inactive individuals to athletes. In addition, RMR may also be used to screen for low energy availability and energy deficiency in athletes, and thus may be useful in identifying individuals at risk for the deleterious consequences of chronic energy deficiency. Given its importance in both clinical and research settings within the fields of exercise physiology, dietetics, and sports medicine, the valid assessment of RMR is critical. However, factors including varying states of energy balance (both short- and long-term energy deficit or surplus), energy availability, and prior food intake or exercise may influence resulting RMR measures, potentially introducing error into observed values. The purpose of this review is to summarize the relationships between short- and long-term changes in energetic status and resulting RMR measures, consider these findings in the context of relevant recommendations for RMR assessment, and provide suggestions for future research.Item International society of sports nutrition position stand: energy drinks and energy shots(2023) Jagim, Andrew R.; Harty, Patrick S.; Tinsley, Grant M. (TTU); Kerksick, Chad M.; Gonzalez, Adam M.; Kreider, Richard B.; Arent, Shawn M.; Jager, Ralf; Smith-Ryan, Abbie E.; Stout, Jeffrey R.; Campbell, Bill I.; VanDusseldorp, Trisha; Antonio, JosePosition Statement: The International Society of Sports Nutrition (ISSN) bases the following position stand on a critical analysis of the literature regarding the effects of energy drink (ED) or energy shot (ES) consumption on acute exercise performance, metabolism, and cognition, along with synergistic exercise-related performance outcomes and training adaptations. The following 13 points constitute the consensus of the Society and have been approved by the Research Committee of the Society: Energy drinks (ED) commonly contain caffeine, taurine, ginseng, guarana, carnitine, choline, B vitamins (vitamins B1, B2, B3, B5, B6, B9, and B12), vitamin C, vitamin A (beta carotene), vitamin D, electrolytes (sodium, potassium, magnesium, and calcium), sugars (nutritive and non-nutritive sweeteners), tyrosine, and L-theanine, with prevalence for each ingredient ranging from 1.3 to 100%. Energy drinks can enhance acute aerobic exercise performance, largely influenced by the amount of caffeine (> 200 mg or >3 mg∙kg bodyweight [BW−1]) in the beverage. Although ED and ES contain several nutrients that are purported to affect mental and/or physical performance, the primary ergogenic nutrients in most ED and ES based on scientific evidence appear to be caffeine and/or the carbohydrate provision. The ergogenic value of caffeine on mental and physical performance has been well-established, but the potential additive benefits of other nutrients contained in ED and ES remains to be determined. Consuming ED and ES 10-60 minutes before exercise can improve mental focus, alertness, anaerobic performance, and/or endurance performance with doses >3 mg∙kg BW−1. Consuming ED and ES containing at least 3 mg∙kg BW−1 caffeine is most likely to benefit maximal lower-body power production. Consuming ED and ES can improve endurance, repeat sprint performance, and sport-specific tasks in the context of team sports. Many ED and ES contain numerous ingredients that either have not been studied or evaluated in combination with other nutrients contained in the ED or ES. For this reason, these products need to be studied to demonstrate efficacy of single- and multi-nutrient formulations for physical and cognitive performance as well as for safety. Limited evidence is available to suggest that consumption of low-calorie ED and ES during training and/or weight loss trials may provide ergogenic benefit and/or promote additional weight control, potentially through enhanced training capacity. However, ingestion of higher calorie ED may promote weight gain if the energy intake from consumption of ED is not carefully considered as part of the total daily energy intake. Individuals should consider the impact of regular coingestion of high glycemic index carbohydrates from ED and ES on metabolic health, blood glucose, and insulin levels. Adolescents (aged 12 through 18) should exercise caution and seek parental guidance when considering the consumption of ED and ES, particularly in excessive amounts (e.g. > 400 mg), as limited evidence is available regarding the safety of these products among this population. Additionally, ED and ES are not recommended for children (aged 2-12), those who are pregnant, trying to become pregnant, or breastfeeding and those who are sensitive to caffeine. Diabetics and individuals with preexisting cardiovascular, metabolic, hepatorenal, and/or neurologic disease who are taking medications that may be affected by high glycemic load foods, caffeine, and/or other stimulants should exercise caution and consult with their physician prior to consuming ED. The decision to consume ED or ES should be based upon the beverage’s content of carbohydrate, caffeine, and other nutrients and a thorough understanding of the potential side effects. Indiscriminate use of ED or ES, especially if multiple servings per day are consumed or when consumed with other caffeinated beverages and/or foods, may lead to adverse effects. The purpose of this review is to provide an update to the position stand of the International Society of Sports Nutrition (ISSN) integrating current literature on ED and ES in exercise, sport, and medicine. The effects of consuming these beverages on acute exercise performance, metabolism, markers of clinical health, and cognition are addressed, as well as more chronic effects when evaluating ED/ES use with exercise-related training adaptions.Item New Equations for Hydrostatic Weighing without Head Submersion(2022) Tesch, Jeff C.; Papadopoulos, Panayiotis; Dolgener, Forrest; Tinsley, Grant M. (TTU)New equations were derived to predict the density of the body (DB) by hydrostatic weighing with the head above water (HWHAW). Hydrostatic weighing with the head below water (HWHBW) was the criterion for DB measurement in 90 subjects (44 M, 46 F). Head volume by immersion (HVIMM) was determined by subtracting the mass in water with the head below water (MWHBW) from the mass in water with the head above water (MWHAW), with subjects at residual lung volume. Equations were derived for head volume prediction (HVPRED) from head measurements and used to correct DB by HWHAW. Equations were also derived for HWHAW using direct regression of DB from uncorrected density (with MWHAW in place of MWHBW). Prediction equations were validated in 45 additional subjects (21 M, 24 F). Results were evaluated using equivalence testing, linear regression, Bland–Altman plots, and paired t-tests. Head girth, face girth, and body mass produced the smallest errors for HVPRED. In both M and F validation groups, equivalence (±2% fat by weight) was demonstrated between body fat percent (BF%) by HWHBW and BF% by HWHAW with HVPRED. Variance in computer-averaged samples of MWHAW was significantly less (p < 0.05) than MWHBW. Prediction error was smaller for BF% by HWHAW with HVPRED than for alternative methods. Conclusions: Equivalence between BF% by HWHBW and BF% by HWHAW with HVPRED was demonstrated and differences were not statistically significant. Weight fluctuations were smaller for HWHAW than HWHBW.Item Offseason Body Composition Changes Detected by Dual-Energy X-ray Absorptiometry versus Multifrequency Bioelectrical Impedance Analysis in Collegiate American Football Athletes(2021) Boykin, Jake R. (TTU); Tinsley, Grant M. (TTU); Harrison, Christine M.; Prather, Jessica; Zaragoza, Javier; Tinnin, Matthias; Smith, Shay; Wilson, Camden; Taylor, Lem W.Tracking changes in body composition may provide key information about the effectiveness of training programs for athletes. This study reports on the agreement between bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) for tracking body composition changes during a seven-week offseason training program in 29 NCAA collegiate American football players. Body composition in subjects (mean ± SD; age: 19.7 ± 1.5 y; height: 179.8 ± 6.6 cm; body mass (BM: 96.1 ± 12.6 kg; DXA body fat: 20.9 ± 4.4%) was estimated using BIA (InBody 770) and DXA (Hologic Horizon) before and after the training intervention. Repeated measures ANOVA and post hoc comparisons were performed. Longitudinal agreement between methods was also examined by concordance correlation coefficient (CCC) and Bland–Altman analysis alongside linear regression to identify bias. Significant method by time interactions were observed for BM (DXA: 1.1 ± 2.4 kg; BIA: 1.4 ± 2.5 kg; p < 0.03), arms fat-free mass (FFM) (DXA: 0.4 ± 0.5 kg; BIA: 0.2 ± 0.4 kg; p < 0.03), and legs FFM (DXA: 0.6 ± 1.1 kg; BIA: 0.1 ± 0.6 kg; p < 0.01). Post hoc comparisons indicated that DXA—but not BIA—detected increases in FFM of the arms and legs. Time main effects, but no method by time interactions, were observed for total FFM (DXA: 1.6 ± 1.9 kg; BIA: 1.2 ± 2.1 kg; p = 0.004) and trunk FFM (DXA: 0.7 ± 1.3 kg; BIA: 0.5 ± 1.0 kg; p = 0.02). Changes in total BM (CCC = 0.96), FFM (CCC = 0.49), and fat mass (CCC = 0.50) were significantly correlated between BIA and DXA. DXA and BIA may similarly track increases in whole-body FFM in American collegiate football players; however, BIA may possess less sensitivity in detecting segmental FFM increases, particularly in the appendages.Item Predicting adaptations to resistance training plus overfeeding using bayesian regression: A preliminary investigation(2021) Smith, Robert W. (TTU); Harty, Patrick S. (TTU); Stratton, Matthew T. (TTU); Rafi, Zad; Rodriguez, Christian (TTU); Dellinger, Jacob R. (TTU); Benavides, Marqui L. (TTU); Johnson, Baylor A. (TTU); White, Sarah J. (TTU); Williams, Abegale D. (TTU); Tinsley, Grant M. (TTU)Relatively few investigations have reported purposeful overfeeding in resistance-trained adults. This preliminary study examined potential predictors of resistance training (RT) adaptations during a period of purposeful overfeeding and RT. Resistance-trained males (n = 28; n = 21 completers) were assigned to 6 weeks of supervised RT and daily consumption of a high-calorie protein/carbohydrate supplement with a target body mass (BM) gain of ≥0.45 kg·wk−1 . At baseline and post-intervention, body composition was evaluated via 4-component (4C) model and ultrasonography. Additional assessments of resting metabolism and muscular performance were performed. Accelerometry and automated dietary interviews estimated physical activity levels and nutrient intake before and during the intervention. Bayesian regression methods were employed to examine potential predictors of changes in body composition, muscular performance, and metabolism. A simplified regression model with only rate of BM gain as a predictor was also developed. Increases in 4C whole-body fat-free mass (FFM; (mean ± SD) 4.8 ± 2.6%), muscle thickness (4.5 ± 5.9% for elbow flexors; 7.4 ± 8.4% for knee extensors), and muscular performance were observed in nearly all individuals. However, changes in outcome variables could generally not be predicted with precision. Bayes R2 values for the models ranged from 0.18 to 0.40, and other metrics also indicated relatively poor predictive performance. On average, a BM gain of ~0.55%/week corresponded with a body composition score ((∆FFM/∆BM)*100) of 100, indicative of all BM gained as FFM. However, meaningful variability around this estimate was observed. This study offers insight regarding the complex interactions between the RT stimulus, overfeeding, and putative predictors of RT adaptations.Item Prevalence of adulteration in dietary supplements and recommendations for safe supplement practices in sport(2023) Jagim, Andrew R.; Harty, Patrick S.; Erickson, Jacob L.; Tinsley, Grant M. (TTU); Garner, Dan; Galpin, Andrew J.The prevalence of dietary supplement use among athletes continues to rise with 60–80% of athletes often reporting current or previous use of dietary supplements. While select dietary ingredients have been shown to improve acute performance and enhance training adaptations over time, it is important to still consider the risk vs. reward for athletes before opting to consume a dietary supplement. Previous work has indicated that certain dietary supplements may pose risks for inadvertent doping, may be susceptible to mislabelling, could be banned by certain governing bodies of sport, or pose health risks for certain populations. The purpose of the current narrative review is to summarize the prevalence of adulteration in dietary sport supplement products, outline the risks of inadvertent doping for athletes, and highlight best practices regarding safe supplementation strategies. Analytical studies have found anywhere from 14 to 50% of samples analyzed from dietary supplement products have tested positive for anabolic agents or other prohibited substances. It is important for the consumer to adhere to safe supplementation strategies, which include following serving size recommendations, cross-referencing ingredient profiles with the list of prohibited substances, choosing quality products that have been verified by a third-party certification program, and being cognizant of consuming multiple dietary supplement products with overlapping ingredient profiles. Once these practices have been considered, it is reasonable for an athlete to utilize dietary supplements as a strategy to optimize performance and health, with a low risk of failing a drug test (adverse analytical finding) and experiencing adverse events.Item Probiotic Administration Increases Amino Acid Absorption from Plant Protein: a Placebo-Controlled, Randomized, Double-Blind, Multicenter, Crossover Study(2020) Jäger, Ralf; Zaragoza, Javier; Purpura, Martin; Iametti, Stefania; Marengo, Mauro; Tinsley, Grant M. (TTU); Anzalone, Anthony J.; Oliver, Jonathan M.; Fiore, Walter; Biffi, Andrea; Urbina, Stacie; Taylor, LemThe fate of dietary protein in the gut is determined by microbial and host digestion and utilization. Fermentation of proteins generates bioactive molecules that have wide-ranging health effects on the host. The type of protein can affect amino acid absorption, with animal proteins generally being more efficiently absorbed compared with plant proteins. In contrast to animal proteins, most plant proteins, such as pea protein, are incomplete proteins. Pea protein is low in methionine and contains lower amounts of branched-chain amino acids (BCAAs), which play a crucial role in muscle health. We hypothesized that probiotic supplementation results in favorable changes in the gut microbiota, aiding the absorption of amino acids from plant proteins by the host. Fifteen physically active men (24.2 ± 5.0 years; 85.3 ± 12.9 kg; 178.0 ± 7.6 cm; 16.7 ± 5.8% body fat) co-ingested 20 g of pea protein with either AminoAlta™, a multi-strain probiotic (5 billion CFU L. paracasei LP-DG® (CNCM I-1572) plus 5 billion CFU L. paracasei LPC-S01 (DSM 26760), SOFAR S.p.A., Italy) or a placebo for 2 weeks in a randomized, double-blind, crossover design, separated by a 4-week washout period. Blood samples were taken at baseline and at 30-, 60-, 120-, and 180-min post-ingestion and analyzed for amino acid content. Probiotic administration significantly increased methionine, histidine, valine, leucine, isoleucine, tyrosine, total BCAA, and total EAA maximum concentrations (Cmax) and AUC without significantly changing the time to reach maximum concentrations. Probiotic supplementation can be an important nutritional strategy to improve post-prandial changes in blood amino acids and to overcome compositional shortcomings of plant proteins. ClinicalTrials.gov Identifier: ISRCTN38903788.Item Publisher Correction: Total and regional appendicular skeletal muscle mass prediction from dual-energy X-ray absorptiometry body composition models (Scientific Reports, (2023), 13, 1, (2590), 10.1038/s41598-023-29827-y)(2023) McCarthy, Cassidy; Tinsley, Grant M. (TTU); Bosy-Westphal, Anja; Müller, Manfred J.; Shepherd, John; Gallagher, Dympna; Heymsfield, Steven B.Correction to: Scientific Reports, published online 14 February 2023 The original version of this Article contained errors. In Figures 2 and 3, the labels and text did not display correctly. The original Figures 2 and 3 and accompanying legends appear below. (Figure presented.) (Figure presented.) Predicted total, arm, and leg skeletal muscle (SM) mass versus corresponding value measured with MRI in the validation sample (n = 47 women; 48 men) on the left (A,C,E) and associated Bland–Altman plots on the right (B,D,F). The regression equations, lines, R2s, and 95% limits of agreement (LOA) are shown in the figures. The statistical significance of each panel is summarized in the text. Total skeletal muscle (SM) mass predicted by Kim’s equation8 versus SM measured with MRI at Kiel (A) and corresponding Bland–Altman plot (B) (n = 475). Total body skeletal muscle (SM) mass predicted by the newly developed Kiel equation versus SM measured with MRI by Kim et al.8 (C) and corresponding Bland–Altman plot (D) (n = 270). The lines of identity (thin solid line), regression equations and lines (solid lines with gray shading indicating 95% CI), and R2s are shown in (A,C). The regression lines with 95% CI and 95% limits of agreement (LOA) (dashed lines) are shown in (B,D). Statistical significance of each panel is summarized in the text. The original Article has been corrected.