Research Summary: The Influence of Fatiguing Exercise on Power Output

Perry, Lena & VanNess, J. Mark & Lydon, William & Rossi, Joey & Jensen, Courtney. (2019). The Influence of Fatiguing Exercise on Power Output. Medicine & Science in Sports & Exercise. 51(6S): 638. DOI: 10.1249/01.mss.0000562407.76129.71.

Presented at the American College of Sports Medicine Annual Meeting (ACSM) 2019.

Key Takeaways

• LOAD was not affected by the fatigue protocol

• EXPLODE was not affected by the fatigue protocol

• DRIVE was affected by the fatigue protocol

• VJ HEIGHT was acutely affected by the fatigue protocol but not chronically

Population: Thirty-five NCAA Division I athletes (9 men, 26 women)

Summary

The questions covered:

• Are the kinetic measurements from vertical jump tests influenced by fatigue based on explosive power outputs?

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 force-time 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.

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