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Made available in DSpace on 2022-04-28T19:41:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Objective: The purpose of the present study was to examine the effect of capsiate supplementation on energy intake, self-reported appetite-related sensations, energy expenditure, fat oxidation, and autonomic parameters with and without an exercise intervention. Methods: Thirteen healthy men completed four randomized trials: two trials for the control condition (without exercise), one with capsiate supplementation (CTRLcap) and one with a placebo (CTRLpla), and two trials for the exercise condition, one with capsiate supplementation (EXcap) and one with placebo (EXpla). Exercise sessions were performed 150 min after the consumption of a standardized breakfast, and supplementation 115 min after consumption of breakfast. An ad libitum buffet was offered 200 min following the completion of the standardized breakfast, and energy intake (EI) and relative energy intake (REI) (relative energy intake = energy intake - energy expenditure related to exercise) were evaluated. Results: There were no significant effects on EI, self-reported appetite sensations, fat oxidation, and energy expenditure. REI was reduced in conditions involving EX when compared to CTRL. A low-frequency to high-frequency ratio for heart rate variability was higher in CTRLcap (1.6 ± 1.1) vs. CTRLpla (1.2 ± 0.9) (p = 0.025; d = 0.39). Conclusion: Acute capsiate supplementation combined with aerobic exercise has limited effects on the examined variables (EI, REI, fat oxidation, energy expenditure, and autonomic parameters), while changes in the autonomic nervous system function in the absence of exercise may have occurred without influencing other variables. Clinical trial registration: ensaiosclinicos.gov.br number, RBR-5pckyr https://ensaiosclinicos.gov.br/rg/RBR-5pckyr. Exercise and Immunometabolism Research Group Department of Physical Education São Paulo State University Institute of Exercise Physiology and Rehabilitation Science School of Kinesiology and Physical Therapy University of Central Florida Department of Sport School of Physical Education and Sport University of São Paulo Exercise and Immunometabolism Research Group Department of Physical Education São Paulo State University

Background: The present study aimed to determine whether energy drink (ED) formulas containing 140 and 100 mg of caffeine have the potential to alter excess postexercise oxygen consumption (EPOC) r...

Boffey, D, Clark, NW, and Fukuda, DH. Efficacy of rest redistribution during squats: Considerations for strength and sex. J Strength Cond Res 35(3): 586-595, 2021-This study examined the kinematic, perceptual, and heart rate responses to rest redistribution (RR) and traditional sets (TS) during the barbell back squat for men and women possessing a wide range of strength levels. Forty-five resistance-trained subjects (30 men and 15 women) performed 40 repetitions of the barbell squat with 65% 1RM load with TS (4 × 10 repetitions, 3-minute rest) or RR (10 × 4 repetitions, 1-minute rest), in a randomized order on days separated by ≥72 hours. The significance was set at p ≤ 0.05 for all statistical analyses. The mean velocity (MV) maintenance was significantly higher for RR compared with TS (87.70 ± 4.50% vs. 84.07 ± 4.48%, respectively; p 0.05) were found for any dependent variables. Rest redistribution produced significantly higher mean HR (143.25 ± 21.11 vs. 135.05 ± 20.74, p < 0.01) and minimum HR (102.77 ± 19.58 vs. 95.97 ± 22.17, p < 0.01). Subjects were better able to maintain velocity with RR compared with TS, while experiencing less perceived effort. Rest redistribution can be recommended for both men and women, but very strong individuals may not improve their velocity maintenance with RR to the same extent as less strong individuals.

The purpose of the present study is two-fold. First, we evaluated whether 8-weeks of combined training (high-intensity intermittent plus strength training) may change brain derived neurotropic factor (BDNF) and lipid parameters (triacylglycerol, HDL-c and non-HDL) in a fasted state. Second, we investigated the effect of an acute session of high-intensity intermittent exercise followed by strength training on systemic BDNF and lipid parameters pre- and post 8-weeks of training. Twenty-one healthy and physically active men were divided into two groups: high-intensity intermittent exercise combined with strength training (HSG; n = 11) and control (CG; n = 10). The HSG exercised for one minute at 100% of speedVO2max (sVO2max) interspersed with one minute of passive recovery followed by strength training (8 exercises with 8-12 repetition maximum loads) for 8-weeks. Heart rate variability, blood pressure, lipid profile, and BDNF concentrations were measured in the fasted state pre- and post-exercise and before and after the 8-week training period. After 8-weeks of exercise training, there was an increase in spectral high frequency component (ms2) and RR interval (p < 0.05), a decreased spectral low frequency component (nu) and heart rate values (p < 0.05), an increase in HDL-c (p < 0.001), and lower BDNF concentrations (p < 0.001). These results suggest that 8-weeks of high-intensity intermittent exercise combined with strength exercise is an effective protective cardio-metabolic strategy capable of increasing HDL-c and BDNF concentrations after an acute exercise session. In the long-term, the modulation on BDNF and HDL-c concentrations may be a determining factor for protection against neurological and cardiovascular diseases.

Boffey, D, Clark, NW, and Fukuda, DH. Efficacy of rest redistribution during squats: Considerations for strength and sex. J Strength Cond Res 35(3): 586-595, 2021-This study examined the kinematic, perceptual, and heart rate responses to rest redistribution (RR) and traditional sets (TS) during the barbell back squat for men and women possessing a wide range of strength levels. Forty-five resistance-trained subjects (30 men and 15 women) performed 40 repetitions of the barbell squat with 65% 1RM load with TS (4 × 10 repetitions, 3-minute rest) or RR (10 × 4 repetitions, 1-minute rest), in a randomized order on days separated by ≥72 hours. The significance was set at p ≤ 0.05 for all statistical analyses. The mean velocity (MV) maintenance was significantly higher for RR compared with TS (87.70 ± 4.50% vs. 84.07 ± 4.48%, respectively; p0.01, d = 0.35). Rating of perceived exertion (active muscles) was significantly lower for RR compared with TS (5.38 ± 1.42 vs. 6.08 ± 1.43, respectively; p = 0.02, d = -0.35). Rating of perceived exertion (overall) was also significantly lower for RR compared with TS (5.60 ± 1.40 vs. 6.48 ± 1.49, respectively; p = 0.02, d = -0.37). The relative strength ratio (relative strength ratio; squat 1RM: body mass) was significantly correlated with the difference in MV maintenance between RR and TS (r = -0.34, p = 0.02). No sex-based differences (p0.05) were found for any dependent variables. Rest redistribution produced significantly higher mean HR (143.25 ± 21.11 vs. 135.05 ± 20.74, p0.01) and minimum HR (102.77 ± 19.58 vs. 95.97 ± 22.17, p0.01). Subjects were better able to maintain velocity with RR compared with TS, while experiencing less perceived effort. Rest redistribution can be recommended for both men and women, but very strong individuals may not improve their velocity maintenance with RR to the same extent as less strong individuals.

This study examined the cardiac autonomic responses, as measured by heart rate variability (HRV), during cycling exercise and short-term rest after energy drink consumption. Seventeen participants (seven males and 10 females, age: 22.8 &plusmn, 3.5 years, BMI: 24.3 &plusmn, 3.3 kg/m2) completed this double-blind, placebo-controlled, counterbalanced crossover design study. Participants received an energy drink formula containing 140 mg of caffeine and a placebo in a randomized order before completing a 10-min steady-state warm up (WUP) and a graded exercise test to exhaustion (GXT) followed by a 15-min short-term rest (STR) period. Heartbeat intervals were recorded using a heart rate monitor. Data were divided into WUP, GXT, and STR phases, and HRV parameters were averaged within each phase. Additionally, root mean square of the standard deviation of R&ndash, R intervals (RMSSD) during GXT was analyzed to determine the HRV threshold. Separate two-way (sex (male vs. female) x drink (energy drink vs. placebo)) repeated measures ANOVA were utilized. Significant increases in high frequency (HF) and RMSSD were shown during WUP after energy drink consumption, while interactions between drink and sex were observed for HRV threshold parameters (initial RMSSD and rate of RMSSD decline). No significant differences were noted during STR. Energy drink consumption may influence cardiac autonomic responses during low-intensity exercise, and sex-based differences in response to graded exercise to exhaustion may exist.

Post-activation potentiation likely acutely improves power-based performance; however, few studies have demonstrated improved endurance performance. Forty collegiate female rowers performed isometric potentiating (ISO), dynamic potentiating (DYN) and control (CON) warm-up protocols on a rowing ergometer, followed by a three-minute all-out test to evaluate their total distance, peak power, mean power, critical power, anaerobic working capacity (W') and stroke rate. Fifteen-second splits were also analysed. ISO consisted of 5 × 5-second static muscle actions with the ergometer handle rendered immovable with a nylon strap, while DYN consisted of 2 × 10-second all-out rowing bouts, separated by a 2-minute rest interval. The participants were divided into high and low experience groups by median experience level (3.75 years) for statistical analysis. Significant differences (DYNCON; p 0.05) were found for distance (+5.6 m), mean power (+5.9 W) and W' (+1561.6 J) for more experienced rowers (n = 19) and no differences for less experienced rowers (n = 18). Mean power in DYN was significantly greater than CON and ISO in the 15-30, 30-45, 45-60 and 60-75 second intervals independent of experience level. These results suggest that DYN may benefit experienced female rowers and that these strategies might benefit a greater power output over shorter distances regardless of experience.

Background Thermogenic fitness drink formulas (TFD) have been shown to increase energy expenditure and markers of lipid metabolism. The purpose of the current study was to compare TFD formulas containing different caffeine concentrations versus a placebo drink on energy expenditure and lipid metabolism at rest and during exercise. Methods Thirty-two recreationally active participants (22.9 ± 0.7 y, 167.1 ± 1.4 cm, 68.8 ± 2.0 kg, 24.0 ± 1.2% fat) who were regular caffeine consumers, participated in this randomized, double-blind, crossover design study. Participants reported to the laboratory on three occasions, each of which required consumption of either a TFD containing 140 mg or 100 mg of caffeine or a placebo. Baseline measurements of resting energy expenditure (REE) and resting fat oxidation (RFO) were assessed using indirect calorimetry as well as measurements of serum glycerol concentration. Measurements were repeated at 30, 60, 90 min post-ingestion. Following resting measures, participants completed a graded exercise test to determine maximal oxygen uptake (V̇O2max), maximal fat oxidation (MFO) and the exercise intensity that elicits MFO (Fatmax), and total energy expenditure (EE). Results A significant interaction was shown for REE (p

The primary purpose of this study was to examine the influence of different work-to-rest ratios on relative energy system utilization during short-term upper-body sprint interval training (SIT) protocols. Forty-two recreationally trained men were randomized into one of three training groups [10 s work bouts with 2 min of rest (10:2, n = 11) or 4 min of rest (10:4, n = 11), or 30 s work bouts with 4 min of rest (30:4, n = 10)] or a control group (CON, n = 10). Participants underwent six training sessions over 2 weeks with 4–6 ‘all-out’ sprints. Participants completed an upper body Wingate test (30 s ‘all-out’ using 0.05 kg kg−1 of the participant’s body mass) pre- and post-intervention from which oxygen consumption and blood lactate were used to estimate oxidative, glycolytic, and adenosine triphosphate-phosphocreatine (ATP-PCr) energy system provisions. An analysis of covariance was performed on all testing measurements collected at post with the associated pre-values used as covariates. Relative energy contribution (p = 0.026) and energy expenditure (p = 0.019) of the ATP-PCr energy system were greater in 10:4 (49.9%; 62.1 kJ) compared to CON (43.1%; 47.2 kJ) post training. No significant differences were found between groups in glycolytic or oxidative energy contribution over a 30 s upper body Wingate test. SIT protocols with smaller work-to-rest ratios may enhance ATP-PCr utilization in a 30 s upper body Wingate over a 2-week intervention.

Background/Objective: Wintertime thermal inversions in narrow mountain valleys create a ceiling effect, increasing concentration of small particulate matter (PM2.5). Despite potential health risks, many people continue to exercise outdoors in thermal inversions. This study measured the effects of ambient PM2.5 exposure associated with a typical thermal inversion on exercise performance, pulmonary function, and biological markers of inflammation. Methods: Healthy, active adults (5 males, 11 females) performed two cycle ergometer time trials outdoors in a counterbalanced design: 1) low ambient PM2.5 concentrations ( .05) for PM2.5 concentration and the measured variables. Conclusion: An acute bout of vigorous exercise during an AQI of “yellow” did not diminish exercise performance in healthy adults, nor did it have a negative effect on pulmonary function or biological health markers. These variables might not be sensitive to small changes from acute, mild PM2.5 exposure. Keywords: Air pollution, Cycle ergometry, Pulmonary function, Time trial, Vigorous exercise

This study compared an 85-tooth versus the standard 62-tooth chainring for power outputs during a Wingate test using a Velotron electromagnetically-braked cycle ergometer.All participants completed trials using both chainring sizes in a repeated-measures cross-over design.Resistance-trained male participants (n=20, 24.6±4.5years) performed two Wingate tests separated by at least 48h. Peak power (PP), mean power (MP), fatigue index (FI), peak cadence, mean cadence, and total work (TW) were recorded.Peak power was not significantly different (p=0.10) between trials (62-tooth=1111±187W vs. 85-tooth=1188±103W). However, MP, mean cadence, and TW were significantly greater (p0.01) for the 85-tooth trial (869±114W, 131±16rpm, and 26,063±3418J) compared to the 62-tooth test (673±136W, 102±24rpm, and 20,199±4066J). Fatigue index was reduced during the 85-tooth trial (49.9±9.1% vs. 61.6±8.8%; p0.01). Agreement was poor with most ICCs≈0.19 and large SEMs.The two options for chainrings on Velotron cycle ergometers should not be interchangeably used with the Wingate test software; the 62-tooth ring is recommended for most applications. Individuals who can attain peak cadence180rpm have less variability and tend to achieve higher power outputs on the 62-tooth ring. We suspect that the manufacturer's software limits peak cadence to 182rpm when using the 85-tooth chainring.

This study evaluated the validity and reliability of the BodyMetrix™ BX2000 A-mode ultrasound for estimating percent body fat (%BF) in athletes by comparing it to skinfolds and the BOD POD. Forty-five (22 males, 23 females) National Collegiate Athletic Association (NCAA) Division-I athletes volunteered for this study. Subjects were measured once in the BOD POD then twice by two technicians for skinfolds and ultrasound. A one-way repeated-measures ANOVA revealed significant differences between body composition methods (F = 13.24, p < 0.01, η² = 0.24). This difference was further explained by a sex-specific effect such that the mean difference between ultrasound and BOD POD was large for females (~ 5% BF) but small for males (~ 1.5% BF). Linear regression using the %BF estimate from ultrasound to predict %BF from BOD POD resulted in an R2 = 0.849, SEE = 2.6% BF and a TE = 4.4% BF. The inter-rater intraclass correlation (ICC) for skinfold was 0.966 with a large 95% confidence interval (CI) of 0.328 to 0.991. The inter-rater ICC for ultrasound was 0.987 with a much smaller 95% CI of 0.976 to 0.993. Both skinfolds and ultrasound had test-retest ICCs ≥ 0.996. The BX2000 ultrasound device had excellent test-retest reliability, and its inter-rater reliability was superior to the skinfold method. The validity of this method is questionable, particularly for female athletes. However, due to its excellent reliability, coaches and trainers should consider this portable and easy to use A-mode ultrasound to assess body composition changes in athletes.