(41) THE INFLUENCE OF FATIGUE ON SPECIFIC SERVICE VELOCITY AND ACCURACY IN NCAA DIVISION 1 TENNIS PLAYERS: A PILOT STUDY

Purpose: Examine the effects of fatigue on, & determine the relationship of peak power & anaerobic capacity to, serve velocity & accuracy in NCAA D1 male & female tennis players. Methods: A convenience sample of 9 male (x̄ age =19.8±1.2yrs, x̄ height=182.3±6.9cm, x̄ bwt=78.2±5.2kg, x̄ BMI=23.6±2.1) & 6 female (x̄ age =19.7±1.4yrs, x̄ height=172.5±10.7cm, x̄ bwt=61.8±12.9kg, x̄ BMI=20.6±2.4) tennis players volunteered for the study. Subjects gave informed consent & completed the PAR-Q+ questionnaire. Subjects were measured with a stadiometer & scale. Subjects completed Wingate Tests (WT) on Day 1, followed by on-court performance testing & fatiguing protocol one week later on Day 2. Fatigue was induced by having subjects perform high-intensity side-to-side ground strokes to 85% of age-predicted heart rate max using the Tanaka formula. Subjects performed 10 consecutive serves to deuce & ad courts before & after the fatiguing protocol. A radar gun was used to measure serve velocity. An independent t-test was used to compare performance between genders, while a dependent t-test was used to determine performance differences within groups. The Pearson-product correlation was used to examine relationships among all variables. Significance level set at p≤0.05. Results: Males differed significantly from females in height (182.3±6.9 vs 172.5±10.7cm, p=0.05), weight (78.2±5.2 vs 61.8±12.9kg, p=0.004), BMI (23.6±2.1 vs 20.6±2.4, p=0.02), peak power (PP) (964.2±88.8 vs 542.8±149.0W, p< 0.001), relative PP (12.4±1.2 vs 8.7±0.7W/kg, p< 0.001), anaerobic capacity (AC) (668.8±55.9 vs 384.5±82.5W, p< 0.001), relative AC (8.7±0.6 vs 6.2±0.7W/kg, p< 0.001), & serve velocity to deuce (106.3±10.0 vs 78.8±3.2mph, p< 0.001; 97.1±9.3 vs 71.5±11.3mph, p=0.001) & ad (111.3±14.1 vs 82.0±12.8mph, p=0.001; 97.9±13.5 vs 72.0±13.8mph, p=0.003) courts before & after induced fatigue (IF). Mass & height were significantly related to serve velocity regardless of gender & court side before & after IF (r=0.64 to 0.76, p=0.10 to 0.001). Serve accuracy measures did not differ between genders to deuce or ad courts before or after IF. Serve velocity was slower within male & female genders to deuce (p=0.001, p=0.002) & ad (p=0.004, p=0.003) courts, respectively, after IF. Serve velocity to both serve sides was significantly correlated to all WT measures before (r=0.70 to 0.86, p=0.003 to < 0.001) & after (r=0.75 to 0.87, p< 0.001) IF, respectively. Neither BMI nor serve velocity outcome was related to any serve accuracy measure. Conclusions: Biometric, WT, & serve velocity, after IF, differed between genders, while serve accuracy did not. Greater biometric measures (e.g. mass, BMI) were related to higher serve velocity regardless of gender or IF. Women appeared to tolerate IF as well as men for serve accuracy. Future research should include lactate testing to definitively determine anaerobic metabolism status, or at least the “talk test” if lactate testing is unavailable. The effects of other IF protocols (e.g. YOYO Intermittent Recovery Test) should also be examined in this population. Practical Applications: Tennis-specific anaerobic testing should include protocols that conclusively induce anaerobic metabolism. S&C programs should focus on improving anaerobic endurance & aerobic recovery with results demonstrating a rightward anaerobic threshold shift. S&C practitioners should consider sport-specific training regimens (e.g. sprint interval training, combined training, plyometrics) to improve the metabolic profile of D1 tennis players. Acknowledgements: None