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 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

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

Dietary macronutrient distribution influences post-exercise substrate utilization in women: A cross-sectional evaluation of metabolic flexibility

Metabolic flexibility is the ability to alter substrate utilization in response to substrate availability, which may influence health and performance. The current study evaluated the effects of habitual macronutrient distribution on energy expenditure (EE) and metabolic flexibility in physically active women

Effects of Coffee and Caffeine Anhydrous Intake During Creatine Loading

The purpose of this study was to determine the effect of 5 d of creatine (CRE) loading alone or in combination with caffeine anhydrous (CAF) or coffee (COF) on upper and lower body strength and sprint performance. Physically active males (n=54; Mean ± SD; Age = 20.1 ± 2.1 yrs; Weight = 78.8 ± 8.8 kg) completed baseline testing, consisting of one-repetition maximum (1RM) and repetitions to fatigue (RTF) with 80% 1RM for bench press (BP) and leg press (LP), followed by a repeated sprint test of five, 10 s sprints separated by 60 s rest on a cycle ergometer to determine peak power (PP) and total power (TP). At least 72 hr later, subjects were randomly assigned to supplement with CRE (5 g creatine monohydrate, 4 times*d−1; n=14), CRE+CAF (CRE + 300 mg*d−1 of CAF; n=13), CRE+COF (CRE + 8.9 g COF, yielding 303 mg caffeine; n=13), or placebo (PLA; n=14) for 5 d. Serum creatinine (CRN) was measured prior to and following supplementation and on day six, participants repeated pre-testing procedures. Strength measures were improved in all groups (p<0.05), with no significant time × treatment interactions. No significant interaction or main effects were observed for PP. For TP, a time × sprint interaction was observed (p<0.05), with no significant interactions between treatment groups. A time × treatment interaction was observed for serum CRN values (p<0.05) that showed increases in all groups except PLA. Four subjects reported mild gastrointestinal discomfort with CRE+CAF, with no side effects reported in other groups. These findings suggest that neither CRE alone, nor in combination with CAF or COF, significantly affected performance compared to PLA

Repetitive negative thinking in the perinatal period and its relationship with anxiety and depression

Background: Rumination and worry represent two types of repetitive negative thinking (RNT), and their predictive and maintaining roles are well-established in depression and anxiety, respectively. Furthermore, there is an emerging literature on the link between RNT and psychological wellbeing in the perinatal period. Methods: We conducted a scoping review of studies that have investigated the relationship between RNT and perinatal depression and anxiety. We identified 87 papers eligible for inclusion in the review; they included cross-sectional and longitudinal studies, as well as treatment evaluations (pilot trials and randomised controlled trials). Results: Cross-sectional studies provided evidence of an association between RNT (i.e., rumination and worry) and depression and anxiety, in both pregnancy and postpartum. Longitudinal findings were mixed. Whilst antenatal worry consistently predicted subsequent depression and anxiety (both later in pregnancy and postpartum), rumination did not consistently predict depression. However, there was some evidence that RNT interacted with other processes to predict later psychopathology. Three randomised controlled trials evaluated whether psychological treatments reduce RNT in the perinatal period, only one of which included a clinical sample. Limitations: No experimental investigations were eligible for inclusion in the review. Conclusions: Further studies are needed to further our understanding of the nature and role of RNT in pregnancy and postpartum, and its consequences for maternal mental health. These include (but are not limited to) experimental investigations, studies with large clinical samples, and RCTs evaluating the effectiveness of psychological interventions targeting RNT to prevent and treat perinatal depression and anxiety

Metabolic characterization of overweight and obese adults

Traditional evaluations of metabolic health may overlook underlying dysfunction in individuals who show no signs of insulin resistance or dyslipidemia. The purpose of this study was to characterize metabolic health in overweight and obese adults using traditional and non-traditional metabolic variables. A secondary purpose was to evaluate differences between overweight/obese and male/female cohorts, respectively

The Effects of Creatine Monohydrate Loading on Exercise Recovery in Active Women throughout the Menstrual Cycle

Creatine supplementation improves anaerobic performance and recovery; however, to date, these outcomes have not been well explored in females. This study evaluated the effect of creatine monohydrate loading on exercise recovery, measured by heart rate variability (HRV) and repeated sprint performance, in women across the menstrual cycle. In this randomized, double-blind, cross-over study, 39 women (mean ± standard deviation: age: 24.6 ± 5.9 years, height: 172.5 ± 42.3 cm, weight: 65.1 ± 8.1 kg, BF: 27.4 ± 5.8%) were randomized to a creatine monohydrate (n = 19; 20 g per day in 4 × 5 g doses) or non-caloric PL group (n = 20). HRV was measured at rest and after participants completed a repeated sprint cycling test (10 × 6 s maximal sprints). Measurements were conducted before and after supplementation in the follicular/low hormone and luteal/high hormone phases. Creatine monohydrate supplementation did not influence HRV values, as no significant differences were seen in HRV values at rest or postexercise. For repeated sprint outcomes, there was a significant phase × supplement interaction (p = 0.048) for fatigue index, with the greatest improvement seen in high hormone in the creatine monohydrate group (−5.8 ± 19.0%) compared to changes in the PL group (0.1 ± 8.1%). Sprint performance and recovery were reduced by the high hormone for both groups. Though not statistically significant, the data suggests that creatine monohydrate could help counteract performance decrements caused by the high hormone. This data can help inform creatine monohydrate loading strategies for females, demonstrating potential benefits in the high hormone phase