Date of Award


Document Type

Open Access Thesis

Degree Name

Master of Science (MS)



First Advisor

Peter M. McGinnis, Ph.D.

Second Advisor

Philip Buckenmeyer, Ph.D.

Third Advisor

Larissa True, Ph.D.


Objective: The purpose of this study was to determine if caffeine ingestion decreased time to contact (TTC), and increased peak hand speed (HS), peak bat barrel speed (BS), and power (P) during a softball bat swing by fatigued and non-fatigued female athletes from an NCAA Division III varsity softball team. Methods: A randomized, single blind counterbalanced design was used to determine if 200 mg of caffeinated gum produced an ergogenic effect on nine female softball players (mean ± SD; age: 19.4 ± 0.7 yrs; height: 169 ± 6 cm; weight: 76.85 ± 10.82 kg) during a softball swing after chewing caffeinated gum for 10 minutes. In the non-fatigued condition the participants received two pieces of caffeinated gum (100 mg each) or a placebo after their warm-up. In the fatigued condition, participants’ received the gum after the completion of a 20 minute high-intensity exercise circuit. The gum was chewed for 10 minutes before being discarded. Once the gum was discarded each participant hit ten softballs off of a tee into fair territory. A Blast Motion Sensor attached to the knob of the bat measured the BS, HS, TTC, and P for each hit. Pre- and post-hitting questionnaires were used to determine fatigue before and after the hitting test using an 11- point fatigue scale. Results: A paired samples t-test was used to determine the change in perceived fatigue within groups. No statistically significant differences were found in prehitting test fatigue and post-hitting test fatigue during the non-fatigued placebo condition, t(8) = -.707, p = .500 and non-fatigued caffeinated condition, t(8) = 1.155, p = .282. There were statistically significant differences in the pre-hitting test fatigue and post-hitting test fatigue during the fatigued placebo condition, t(8) = 5.000, p = .001 as well as the fatigued caffeinated condition, t(8) = 4.603, p = .002. A two-way repeated measures analysis of variance (ANOVA) was used to test the differences in BS, HS, TTC and P between the iv caffeine and placebo trails within the fatigued and non-fatigued conditions. There were no statistically significant interactions between fatigue status and supplementation on BS, HS, TTC, and P, so main effects were analyzed. Main effects indicated statistically significant differences in mean BS and P between the placebo (BS = 53.9 mph; P = 1.75 kW) and caffeinated conditions (BS = 55.0 mph; P = 1.83 kW), F(1,8) = 8.651, p = .019; F(1,8) = 6.375, p = .036. Conclusion: Based on these results, it is suggested that caffeinated gum can be beneficial to bat swing performance and perceived fatigue in female softball players.