Positional Analysis of Body Composition Using Dual-Energy X-Ray Absorptiometry in National Collegiate Athletic Association Division I Football and Men's Lacrosse

Influence of cardiorespiratory fitness and body composition on resting and post-exercise indices of vascular health in young adults

Poor cardiorespiratory fitness may mediate vascular impairments at rest and following an acute bout of exercise in young healthy individuals. This study aimed to compare flow mediated dilation (FMD) and vascular augmentation index (AIx75) between young adults with low, moderate, and high levels of cardiorespiratory fitness before and after an acute bout of aerobic exercise. Forty-three participants (22 men; 21 women) between 18 and 29 years of age completed the study. Participants were classified into low, moderate, and high health-related cardiorespiratory fitness groups according to age- and sex-based relative maximal oxygen consumption (V ˙ O2 max) percentile rankings. FMD was performed using Doppler ultrasound and AIx75 was performed using pulse wave analysis at baseline and 60-min after a 30-min bout of treadmill running at 70% V ˙ O2 max. A significant interaction (p ​= ​0.047; ηp2 ​= ​0.142) was observed, with the moderate fitness group exhibiting a higher FMD post-exercise compared with baseline ([6.7% ​± ​3.1%] vs. [8.5% ​± ​2.8%], p ​= ​0.028; d ​= ​0.598). We found a significant main effect of group for AIx75 (p ​= ​0.023; ηp2 ​= ​0.168), with the high fitness group exhibiting lower AIx75 compared to low fitness group ([-10% ​± ​10%] vs. [2% ​± ​10%], respectively, p ​= ​0.019; g ​= ​1.07). This was eliminated after covarying for body fat percentage (p ​= ​0.489). Our findings suggest that resting FMD and AIx75 responses are not significantly influenced by cardiorespiratory fitness, but FMD recovery responses to exercise may be enhanced in individuals with moderate cardiorespiratory fitness levels.

High-intensity functional exercise does not cause persistent elevations in augmentation index in young men and women

Elevations in central augmentation index (AIx) are predictive of cardiovascular disease. Our objective was to examine AIx immediately and 24-hrs following an acute bout of high-intensity functional training (HIFT) in apparently healthy young adults. A second aim compared the exercise induced AIx recovery response between men and women. Thirty-two recreationally active younger adults (n=16 men) were tested. Baseline central hemodynamic measures were assessed, followed by a single bout of bodyweight HIFT. The HIFT included four rounds of burpees, jump squats, split squats, and walking lunges. Assessments were repeated 5-, 10-, 15- and 24-hrs post exercise. AIx was normalized to a heart rate of 75 bpm (AIx75). There was a significant main effect of time on AIx75 across all groups (p<0.001) with AIx75 increasing at all acute timepoints compared with baseline and returning to resting values 24-hrs post-exercise. When examining sex differences after covarying for height and body fat percentage, we found no time*sex interaction (p=0.62), or main effect for sex (p=0.41), but the significant main effect of time remained (p<0.001). The AIx75 response to HIFT follows a similar recovery pattern as previously studied modes of exercise with no residual effects 24 hrs later and no differences between men and women indicating no persistent cardiovascular strain in younger adults participating in this mode of exercise.