Enjoyment of high-intensity interval training in an overweight/obese cohort: a short report

Exercise enjoyment has been shown to be important for adherence. Minimal data exist on enjoyment of intense exercise, especially in clinical populations. The purpose of this study was to evaluate enjoyment levels of overweight and obese subjects undergoing 3 weeks of high-intensity interval training. Forty-two generally healthy overweight and obese men and women (body mass index = 30·8 ± 4·8 kg × m−2) volunteered for this study. Exercise enjoyment was quantified using the Exercise Enjoyment Scale before and after each of nine total interval training sessions, over a three-week period. Heart rate and ratings of perceived exertion (RPE) were measured at the end of each interval and training session. There were no significant differences in enjoyment between training groups (P > 0·05). Exercise enjoyment improved significantly over the three-week training phase (P < 0·05). Enjoyment levels were relatively high to begin training: mean ± SD: 4·2 ± 1·0 out of a 7 point scale. Heart rate and RPE were significantly reduced (P < 0·05) from pre- (day 1) to post-training (day 9). High-intensity interval training may be an enjoyable form of exercise for overweight and obese men and women. Enjoyment levels may continue to increase following initial introduction to this type of training. Due to the small time demand and high enjoyment, interval training may be an effective exercise approach in a sedentary population

Body Composition and Muscle Characteristics of Division I Track and Field Athletes

The purpose of this study was to evaluate event-specific body composition and muscle characteristics of track and field athletes, and to assess body composition changes after one year. Sixty collegiate track and field athletes (Mean ± SD; Age = 19.2 ± 1.4 yrs, Height = 174.6 ± 9.0 cm, Weight = 71.5 ± 12.5 kg) were stratified into six event groups. Total and regional body composition measurements were assessed using dual-energy x-ray absorptiometry. A panoramic scan of the vastus lateralis was taken with B-mode ultrasound to determine muscle cross sectional area (mCSA) and echo intensity (EI). Body composition measurements were repeated a year later in a subset of returning athletes (n=33). Throwers had significantly more absolute fat mass (FM; 21.6 ± 11.0 kg), total body mass (89.7 ± 17.4 kg), percent fat (23.6 ± 7.8) and trunk fat (9.4 ± 5.8 kg) than all other event groups (p0.05), but relative to body mass had relatively less LM (0.72 ± 0.08 kg; p<0.05). Despite high FM, throwers had lower EI (63.4 ± 5.2 a.u). After one year, relative armLM increased slightly in all event groups (p<0.05). Evaluation of muscle characteristics in addition to total and regional body composition may be valuable for improving performance, injury prevention, and assessing health risks. With appropriate training, track and field athletes may be able to minimize losses in LM and gains in FM between seasons

Seasonal Effects on Body Composition, Muscle Characteristics, and Performance of Collegiate Swimmers and Divers

Previous researchers have indicated the importance of body composition and muscle quality in athletic performance. However, body composition and muscle-quality measures in swimmers and divers over a training season have yet to be evaluated

Effects of high-intensity interval training on cardiometabolic risk factors in overweight/obese women

The purpose of this study was to evaluate two practical interval training protocols on cardiorespiratory fitness, lipids, and body composition in overweight/obese women. Thirty women (mean ± SD; Weight: 88.1 ± 15.9 kg; BMI: 32.0 ± 6.0 kg·m2) were randomly assigned to ten 1-minute high-intensity intervals (90%VO2peak, 1min recovery), or five 2-minute high-intensity intervals (80-100% VO2peak, 1 min recovery), or control. Peak oxygen uptake (VO2peak), peak power output, body composition, and fasting blood lipids were evaluated before and after 3 weeks of training, completed 3 days per week. Results from ANCOVA analyses demonstrated no significant training group differences for any primary variables (p>0.05). When training groups were collapsed, 1MIN and 2MIN resulted in a significant increase in peak power output (∆18.9 ± 8.5 watts; p=0.014) and time to exhaustion (∆55.1 ± 16.4 sec; p=0.001); non-significant increase in VO2peak (∆2.36 ± 1.34 ml·kg−1·min−1; p=0.185); and a significant decrease in fat mass (∆−1.96 ± 0.99kg; p=0.011). Short-term interval exercise training may be effective for decreasing fat mass and improving exercise tolerance in overweight and obese women

Metabolic adaptation to weight loss: implications for the athlete

Abstract Optimized body composition provides a competitive advantage in a variety of sports. Weight reduction is common among athletes aiming to improve their strength-to-mass ratio, locomotive efficiency, or aesthetic appearance. Energy restriction is accompanied by changes in circulating hormones, mitochondrial efficiency, and energy expenditure that serve to minimize the energy deficit, attenuate weight loss, and promote weight regain. The current article reviews the metabolic adaptations observed with weight reduction and provides recommendations for successful weight reduction and long term reduced-weight maintenance in athletes

Dietary protein intake is associated with maximal and explosive strength of the leg flexors in young and older blue collar workers

The aim of this study was to investigate the association between dietary PRO intake and maximal and rapid strength of the leg flexors in blue collar (BC) working men. Twenty-four young (age=23.2±2.1 yrs), and nineteen older aged (age=52.8±5.2 yrs) men employed in BC occupations completed a three day dietary record and isometric strength testing of the leg flexors. Food logs were analyzed for total protein (TPRO) and essential amino acid (EAA) intake. Rapid and maximal strength capacities were examined from the rate of torque development at 50ms (RTD50) and peak torque (PT) of the torque-time curves, respectively. Pearson correlations and partial correlations were used to examine the relationships between TPRO and EAA intake on strength variables. PT was positively correlated to TPRO and EAA intake in the young (r=0.439 and 0.431;P0.05) between TPRO and strength variables when controlling for EAA intake. TPRO intake explained 20–44% of the variance in rapid and maximal strength for both age groups. EAA intake was largely responsible for the positive relationship between PRO intake and strength. Across young and older aged blue collar working male populations, protein consumption was associated with both maximal and explosive strength capacities of the leg flexors muscle group

Effects of coffee and caffeine anhydrous on strength and sprint performance

Caffeine and coffee are widely used among active individuals to enhance performance. The purpose of the current study was to compare the effects of acute coffee (COF) and caffeine anhydrous (CAF) intake on strength and sprint performance. Fifty-four resistance-trained males completed strength testing, consisting of one-rep max (1RM) and repetitions to fatigue (RTF) at 80% of 1RM for leg press (LP) and bench press (BP). Participants then completed five, ten-second cycle ergometer sprints separated by one minute of rest. Peak power (PP) and total work (TW) were recorded for each sprint. At least 48 hours later, participants returned and ingested a beverage containing CAF (300 mg flat dose; yielding 3–5 mg/kg bodyweight), COF (8.9 g; 303 mg caffeine), or placebo (PLA; 3.8 g noncaloric flavoring) 30 minutes before testing. LP 1RM was improved more by COF than CAF (p=0.04), but not PLA (p=0.99). Significant interactions were not observed for BP 1RM, BP RTF, or LP RTF (p>0.05). There were no sprint × treatment interactions for PP or TW (p>0.05). 95% confidence intervals revealed a significant improvement in sprint 1 TW for CAF, but not COF or PLA. For PLA, significant reductions were observed in sprint 4 PP, sprint 2 TW, sprint 4 TW, and average TW; significant reductions were not observed with CAF or COF. Neither COF nor CAF improved strength outcomes more than PLA, while both groups attenuated sprint power reductions to a similar degree. Coffee and caffeine anhydrous may be considered suitable pre-exercise caffeine sources for high-intensity exercise

High-intensity interval training: Modulating interval duration in overweight/obese men

High-intensity interval training (HIIT) is a time-efficient strategy shown to induce various cardiovascular and metabolic adaptations. Little is known about the optimal tolerable combination of intensity and volume necessary for adaptations, especially in clinical populations

Longitudinal Body Composition Changes in NCAA Division I College Football Players

Many athletes seek to optimize body composition to fit the physical demands of their sport. American football requires a unique combination of size, speed, and power. The purpose of the current study was to evaluate longitudinal changes in body composition in Division I collegiate football players. For 57 players (Mean ± SD; Age=19.5 ± 0.9 yrs; Height=186.9 ± 5.7 cm; Weight=107.7 ± 19.1 kg), body composition was assessed via dual-energy x-ray absorptiometry in the off-season (March-Pre), end of off-season (May), mid-July (Pre-Season), and the following March (March-Post). Outcome variables included weight, body fat percentage (BF%), fat mass (FM), lean mass (LM), android (AND) and gynoid (GYN) fat, bone mineral content (BMC), and bone density (BMD). For a subset of athletes (n=13 out of 57), changes over a 4-year playing career were evaluated with measurements taken every March. Throughout a single year, favorable changes were observed for BF% (Δ=−1.3 ± 2.5%), LM (Δ=2.8 ± 2.8 kg), GYN (Δ=−1.5 ± 3.0%), BMC (Δ=0.06 ± 0.14 kg), and BMD (Δ=0.015 ± 0.027g·cm−2; all p<0.05). Across four years, weight increased significantly (Δ=6.6 ± 4.1kg), and favorable changes were observed for LM (Δ=4.3 ± 3.0 kg), BMC (Δ=0.18 ± 0.17 kg), and BMD (Δ=0.033 ± 0.039 g·cm−2; all p<0.05). Similar patterns in body composition changes were observed for linemen and non-linemen. Results indicate that well-trained collegiate football players at high levels of competition can achieve favorable changes in body composition, even late in the career, which may confer benefits for performance and injury prevention