Despite the known importance of body composition in relation to performance and health of athletes, this study appears to be the first, or one of very few, to evaluate body composition measures from the beginning to end of season for NCAA DI collegiate baseball players and assess their dietary intake. Baseball players from the 2015-2019 seasons were included in the study (n=78; age=19.8±1.28). DXA scans performed at the start and end of season were analyzed and 3-day food records analyzed via ESHA software were utilized to assess dietary intake. Groups were stratified to examine differences in players’ positions (Pitchers vs. Position Players) and first-year status effects (Freshman/Transfer vs. Sophomore/Junior/Seniors). Based on the study’s findings, body mass and lean body mass significantly decreased from the beginning to end of season for the overall team (p= 0.002; 0.026). Position Players exhibited a significant decline in body mass, region percent fat, and fat mass (p=0.00, 0.014, and 0.021, respectively) while Pitchers did not demonstrate any significant changes. First-year players experienced an increase in visceral adipose tissue volume and visceral adipose tissue mass (p= 0.004, 0.004) and Sophomore/Junior/Seniors group experienced a significant decrease in body mass, region % fat, and fat mass from the beginning to end of season (p=0.00, 0.017, and 0.023, respectively). The team on average consumed 6% less than the recommended value for protein, 36% less than recommendation for carbohydrate and 10% above the recommended intake amount was determined for fat. Overall, the team consumed 18% less than their estimated total calorie recommended goal. We believe the study presents interesting findings that may be helpful for collegiate baseball programs, and potentially athletes in similar sports, to improve the performance, development and health of young student athletes.

Physical fatigue impairs performance during high power, short duration activities. As technological developments permit new methods of measuring this effect, it is important to validate existing paradigms. The purpose was to determine if kinetic measurements from vertical jump (VJ) tests are influenced by fatigue based on explosive power outputs. A sample of athletes (9 men, 26 women) from a Division I NCAA sports program completed testing. To establish baseline VJ kinetics, athletes performed a controlled warm-up and then completed six jumps using Sparta Science technology, each separated by 15s rest. Sparta software computed three force outputs: Load, Explode and Drive. After baseline VJ calculation, performed an anaerobic fatigue protocol on a cycle ergometer: three 15s sprints separated by 10s rest. Max and average power were recorded from the cycle trials. Subjects then repeated the VJ protocol. This pattern was repeated until six sets of VJ were recorded. Repeated measures ANOVA tested differences between successive VJ performances. Male athletes were 20.8 ± 1.5years old, weighed 175.8 ± 14.0lbs, had a baseline VJ of 46.9 ± 3.6cm, Load of 53.6 ± 13.3, Explode of 49.4 ± 6.6, and Drive of 49.4 ± 11.9. Female athletes were 20.2 ± 1.2years old, weighed 142.3 ± 13.2lbs, had a baseline VJ of 32.7 ± 4.3cm, Load of 49.8 ± 46.1, Explode of 40.7 ± 8.0, and Drive of 63.1 ± 49.7. Differences between sex were weight (p <0.001), VJ (p <0.001), and Explode (p=0.006). ANOVA found VJ height to decrease between baseline and trial 2 (p <0.001), no difference between sex (p=0.210); and between trials 2 and 6 VJ height was consistent (p>0.400). Load was not affected by the fatigue protocol across the total sample (p=0.418) or by sex (p=0.239). Explode was not affected by fatigue across the sample (p=0.233) or by sex (p=0.406). Drive was affected by fatigue (p=0.040), decreasing in successive trials; no interaction with sex (p=0.742). VJ is more sensitive to fatigue than Sparta’s force plate calculations. An initial fatiguing insult was sufficient to compromise performance, whereas accumulated fatigue didn’t have an additive effect. Drive was the only force variable that was affected by fatigue.