TEST-RESTEST RELIABILITY OF BIOIMPEDANCE SPECTROSCOPY FOR THE ANALYSIS OF BODY COMPOSITION IN PHYSICALLY ACTIVE MALES

Tyler W.D. Muddle1,2, Patrick M. Tomko1,2, Ryan J. Colquhoun1,2, Mitchel A. Magrini1, Nile F. Banks1,2, Nathaniel D.M. Jenkins1,2 1Applied Neuromuscular Physiology Laboratory 2Laboratory for Applied Nutrition and Exercise Science Oklahoma State University, Stillwater OK No previous studies, to our knowledge, have examined the reliability of bioimpedance spectroscopy (BIS) for the evaluation of body composition. PURPOSE: To evaluate the test-retest reliability of BIS for the assessment of total body water (TBW), extracellular water (ECW), and intracellular water (ICW) content, as well as fat mass (FM), fat-free mass (FFM), and body fat percentage (BF%) in physically active males. METHODS: Sixteen males (Mean ± SD, 25 ± 3 y, 90 ± 11 kg, 176 ± 6 cm) were assessed at two visits, separated by 2 – 7 days. During each visit, participants rested quietly for 3 – 5 min in a supine position with their arms abducted ≥ 30° away from their torso and legs separated prior to their assessment. Two single-tab electrodes were placed on the right side of the body 5 cm apart on both the dorsal surface of the wrist and dorsal surface of the ankle, respectively. The BIS device was used to estimate TBW, ECW, and ICW (liters; L) based on Cole modelling with Hanai mixture theory, which were then used to calculate FM (kg), FFM (kg), and BF%. Reliability was examined by calculating the intraclass correlation coefficient (ICC; model 2,1) and standard error of measurement (SEM). The coefficient of variation (CV) was calculated by expressing the SEM relative to the grand mean (%). The 95% confidence interval (CI) for each ICCwas calculated and used to test the null hypothesis that each ICC was equal to zero. Systematic variability was assessed for each variable via a paired t-test. RESULTS: Reliability statistics are displayed in Table 1. None of the dependent variables displayed systematic variability (p \u3e 0.05). ‘Excellent’ relative and absolute reliability was observed among all body water (ICC = 0.91 – 0.99; CVs = 1.08 – 3.50%) and body mass (ICC = 0.95 – 0.99; CVs = 1.10 – 6.99%) measurements. CONCLUSION: These results indicate that the BIS device used in this study allows for the reliable assessment of TBW, ECW, ICW, FM, FFM, and BF% in physically active men

SIMILAR ADAPTATIONS FOLLOWING TWO HIGH INTENSITY INTERVAL TRAINING CONFIGURATIONS: 10s:5s VERSUS 20s:10s WORK-TO REST RATIO

Masoud Moghaddam1, Carlos A. Estrada1, Tyler W.D. Muddle1, Mitchel A. Magrini1, Nathaniel D.M. Jenkins1, Bert H. Jacobson1, FACSM 1Oklahoma State University, Stillwater, OK High intensity interval training (HIIT) refers to a group of short bouts separated by rest periods. Intensity and duration of exercise and rest periods are the most significant factors in optimizing HIIT adaptations. Since a 2:1 work-to-rest ratio causes a higher oxygen deficit, a 10s:5s work-to-rest ratio was incorporated to establish a shorter yet potentially effective interval duration. PURPOSE: This study compared the effects of ultrashort (UH) versus short (SH) functional HIIT on body composition, vastus lateralis cross sectional area (VL CSA), anaerobic, and aerobic performance. METHODS: Thirty-four recreationally active participants were randomly assigned to SH (8 males and 9 females) and UH (8 males and 9 females) groups and completed 6 cycles of 6 exercises at ~90% of maximal heart rate (i.e. kettlebell snatches; step-up jumps; jumping jacks; front squat; burpees; high knees) 3 d/wk for 4 weeks. SH was performed with 20s:10s work-to-rest ratio, and a 2-minute recovery between cycles, while UH was completed with 10s:5s work-to-rest ratio, and 1-minute recovery. Fat mass (FM), fat free mass (FFM), VL CSA, Wingate anaerobic capacity (i.e. peak power [PP] and anaerobic power [AP]), and aerobic fitness (i.e. VO2max) were measured before and after the intervention and analyzed with 2-way mixed factorial ANOVAs. RESULTS: FM did not significantly (p\u3e0.05) change, however, both groups significantly (p\u3c0.05) improved FFM (UH: 60.8 ± 15.0 to 61.5 ± 15.2 kg, SH: 54.3 ± 11.5 to 55.5 ± 11.0 kg), as well as VL CSA (UH = 24.8 ± 6.2 to 27.1 ± 6.3 cm, SH = 25.6 ± 5.1 to 27.9 ± 5.5 cm). Additionally, anaerobic (UH: PP = 913 ± 305 to 1033 ± 300 W; AP = 11.5 ± 1.1 to 12.6 ± 1.1 W/kg, SH: PP = 839 ± 162 to 887 ± 181 W; AP = 11.8 ± 1.1 to 12.5 ± 1.2 W/kg) and aerobic capacity (UH: VO2max = 35.8 ± 6.9 to 38.9 ± 6.1 ml/kg/min, SH: VO2max = 39.7 ± 9.3 to 42.6 ± 9.1 ml/kg/min) significantly (p\u3c0.05) increased in both groups. There were no significant (p\u3e0.05) differences between groups. CONCLUSION: These results suggest that HIIT at a 10s:5s work-to-rest ratio can improve physical fitness with a shorter time commitment. Future studies are needed to examine a differential effect of these protocols for men versus women. Since the participants would be best categorized as low-fitness, caution is warranted when extrapolating these results to others with higher-fitness levels

IMPACT OF AGE AND PHYSICAL ACTIVITY ON POSTPRANDIAL VASCULAR RESPONSES

Nicholas A. Koemel1, Christina M. Sciarrillo1, Katherine B. Bode1, Madison D. Dixon1, Edralin A. Lucas1, Nathaniel D.M. Jenkins1, Sam R. Emerson1 1Oklahoma State University, Stillwater, OK, USA The consumption of a high-fat meal (HFM) can induce postprandial lipemia (PPL) resulting in endothelial dysfunction. However, there is limited research describing the influence of age and physical activity level on postprandial vascular function. PURPOSE: The purpose of this project was to determine the impact of age and physical activity on vascular function before and acutely following HFM consumption in healthy men and women. METHODS: We recruited 4 groups of adults: younger active (YA; age 22.1 ± 1.4 y; n = 9), younger inactive (YI; age 22.6 ± 3.7 y; n = 8), older active (OA; age 68.4 ± 7.7 y; n = 8), and older inactive (OI; age 67.7 ± 7.2 y; n = 7). Following a 10hr overnight fast and 2 days of exercise avoidance, vascular function was assessed using flow-mediated dilation (FMD) in the brachial artery at baseline (BL), 2 hr, and 4 hr after consumption of a HFM (12 kcal/kg; 63% fat, 34% carbohydrate). To determine FMD, a wrist cuff was inflated to50 mmHg greater than the participant\u27s systolic blood pressure for 4 minutes and then released inducing a hyperemic dilatory response. RESULTS: A one-way ANOVA revealed BL group differences (p= 0.002) in FMD (YA = 6.36 ± 1.70%; YI = 3.98 ± 1.67%, OA = 4.82 ± 1.27%, OI = 3.27 ± 1.33%), with YA exhibiting significantly greater FMD than YI (p = 0.02) and OI (p = 0.002). There was not a significant group effect (p = 0.06) or interaction (p = 0.08) in a two-way ANOVA, but there was a significant time effect (p = 0.008). Across groups, FMD decreased significantly from BL to 4 hr after the meal (Mean diff: 1.19%; 95% CI: 0.27 to 2.11). However, FMD was not significantly different comparing BL vs 2 hr (p = 0.06) or 2 hr vs 4 hr (p = 0.73). CONCLUSION: In this study, younger active individuals demonstrated the highest FMD in the fasted state. However, all groups exhibited impaired vascular function 4 hr after the HFM consumption relative to fasting. Future studies are needed to better understand the mechanism and time course of HFM-induced vascular impairment, as well as potential lifestyle factors that modify this response. ACKNOWLEDGMENTS: This study was funded by the College of Human Sciences at Oklahoma State University

International society of sports nutrition position stand: caffeine and exercise performance

Following critical evaluation of the available literature to date, The International Society of Sports Nutrition (ISSN) position regarding caffeine intake is as follows:1.Supplementation with caffeine has been shown to acutely enhance various aspects of exercise performance in many but not all studies. Small to moderate benefits of caffeine use include, but are not limited to: muscular endurance, movement velocity and muscular strength, sprinting, jumping, and throwing performance, as well as a wide range of aerobic and anaerobic sport-specific actions.2.Aerobic endurance appears to be the form of exercise with the most consistent moderate-to-large benefits from caffeine use, although the magnitude of its effects differs between individuals.3.Caffeine has consistently been shown to improve exercise performance when consumed in doses of 3–6 mg/kg body mass. Minimal effective doses of caffeine currently remain unclear but they may be as low as 2 mg/kg body mass. Very high doses of caffeine (e.g. 9 mg/kg) are associated with a high incidence of side-effects and do not seem to be required to elicit an ergogenic effect.4.The most commonly used timing of caffeine supplementation is 60 min pre-exercise. Optimal timing of caffeine ingestion likely depends on the source of caffeine. For example, as compared to caffeine capsules, caffeine chewing gums may require a shorter waiting time from consumption to the start of the exercise session.5.Caffeine appears to improve physical performance in both trained and untrained individuals.6.Inter-individual differences in sport and exercise performance as well as adverse effects on sleep or feelings of anxiety following caffeine ingestion may be attributed to genetic variation associated with caffeine metabolism, and physical and psychological response. Other factors such as habitual caffeine intake also may play a role in between-individual response variation.7.Caffeine has been shown to be ergogenic for cognitive function, including attention and vigilance, in most individuals.8.Caffeine may improve cognitive and physical performance in some individuals under conditions of sleep deprivation.9.The use of caffeine in conjunction with endurance exercise in the heat and at altitude is well supported when dosages range from 3 to 6 mg/kg and 4–6 mg/kg, respectively.10.Alternative sources of caffeine such as caffeinated chewing gum, mouth rinses, energy gels and chews have been shown to improve performance, primarily in aerobic exercise.11.Energy drinks and pre-workout supplements containing caffeine have been demonstrated to enhance both anaerobic and aerobic performance

Nutritional and Supplementation Strategies to Prevent and Attenuate Exercise-Induced Muscle Damage: a Brief Review

Exercise-induced muscle damage (EIMD) is typically caused by unaccustomed exercise and results in pain, soreness, inflammation, and reduced muscle function. These negative outcomes may cause discomfort and impair subsequent athletic performance or training quality, particularly in individuals who have limited time to recover between training sessions or competitions. In recent years, a multitude of techniques including massage, cryotherapy, and stretching have been employed to combat the signs and symptoms of EIMD, with mixed results. Likewise, many varied nutritional and supplementation interventions intended to treat EIMD-related outcomes have gained prominence in the literature. To date, several review articles have been published that explore the many recovery strategies purported to minimize indirect markers of muscle damage. However, these articles are very limited from a nutritional standpoint. Thus, the purpose of this review is to briefly and comprehensively summarize many of these strategies that have been shown to positively influence the recovery process after damaging exercise. These strategies have been organized into the following sections based on nutrient source: fruits and fruit-derived supplements, vegetables and plant-derived supplements, herbs and herbal supplements, amino acid and protein supplements, vitamin supplements, and other supplements