Longitudinal Correlation of Sleep Time, Strength Gains, and Performance in Collegiate Baseball Players

Abstract

Sleep time influences lean body mass in dieting adults; sleep has not been demonstrated to influence anabolic processes in collegiate athletes. Longer sleep time is correlated with improved performance in sports. PURPOSE: We followed 14 baseball players to describe sleep patterns and investigate their relationship to strength gains from weight training and performance parameters over a semester. METHODS: The study was approved by Roanoke College IRB. 14 baseball players were chosen at random and agreed to participate. Body composition was determined pre and post study by bioimpedence. Sleep/wake time were recorded using Actigraph monitor. Participants followed standard preseason conditioning & weight lifting regimen; 3 lift maximum pre and post study were recorded for biceps curl, dip, chest press, shoulder press, pull up and squat. Pitchers accuracy of fastball and skill pitches (curve, etc) were recorded during games. RESULTS: 13 of 14 athletes completed the study. 1 withdrew due to injury. The players sleep profile showed a significant difference between the shortest (311+/- 48 min/night) and longest sleepers (430+/- 54 min/night) (p<0.05). For statistical evaluation, “short sleepers” (<6.0 hours, n=8) and “long sleepers” (>6 hours, n=5) categories were used. Body composition: long sleepers tended to gain less body fat (0.22 +/- 0.64%) compared to short sleepers (0.63 +/- 1.65%) but was not significant (p=0.61) Long sleepers had strength gains in all 6 weight categories compared to short sleepers but changes were not significant (p=0.6). Pitching accuracy (strikes/total pitches) for fast ball correlate with night-before-performance sleep time, but were not significant. CONCLUSION: This study demonstrates remarkable variation of sleep time in baseball athletes over a semester; the shortest sleepers had about 180 fewer hours of sleep than longest sleepers. Pilot data on weight training and performance demonstrates interesting trends relative to sleep time, but the study is not powerful enough to generate statistically significance. Our body composition results agree with previously published data and suggest further study is warranted.