Affiliations: [a] Applied Neuromuscular Physiology Laboratory, Kinesiology, Applied Health and Recreation, Oklahoma State University, Stillwater, OK, USA | [b] Applied Physiology and Sports Medicine Laboratory, Department of Food, Nutrition, Dietetics and Health, Kansas State University, Manhattan, KS, USA | [c] Department of Wellness, Oklahoma State University, Stillwater, OK, USA
Correspondence:
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Corresponding author: Eric C. Conchola, Department of Wellness , Fitness Specialist, Oklahoma State University, Stillwater, OK 74078, USA. Tel.: +1 405 744 8743; Fax: +1 405 744 7670; E-mail: eric.conchola@okstate.edu.
Abstract: OBJECTIVE: The purpose of this investigation was to examine the effects of two back squat exercise protocols on recovery responses of maximal unloaded velocity (Vmax) and angular acceleration (ACC240, ACC500) of the knee extensors. METHODS: Fourteen resistance-trained men (mean ± SD: age = 22.07 ± 2.6 years) and sixteen women (age = 21.75 ± 1.0 years) performed maximum voluntary contractions at 240∘⋅ s-1 and 500∘⋅ s-1 before (Pre) and after (Post0-Post30) a squat exercise using either a power-endurance (PE) (5 × 16 at 40% one-repetition maximum), or controlled hypertrophic (CH) (5 × 8 at 80% one-repetition maximum) protocol. RESULTS:There was a significant main effect for time (p⩽ 0.001) in which ACC240 was greater at Pre compared to Post0, Post15 and Post30 (p= 0.001–0.023), no differences were observed at Post7 (p= 0.186). For ACC500, all post-recovery time phases (Post0-Post30) were lower than Pre (p⩽ 0.001). A sex × intensity × time (p= 0.040) interaction was observed for Vmax where only the CH protocol was significantly decreased (p= 0.019) for the males at Post0. All other post-recovery time phases for Vmax were lower compared to Pre for both protocols (p= 0.002–0.025). CONCLUSIONS: Similar fatigue and recovery-related responses were observed between genders in regards to ACC and Vmax following volume-matched PE and CH squat protocols. Knowing that a variety of populations implement compound movements into their resistance training routines, the present findings suggest that ACC and Vmax may be negatively affected following moderate to heavy exercise for up to 30 minutes. Thus, assessing ACC and Vmax post-exercise may be a valuable measure in identifying the residual consequences of fatigue over a short-term recovery period.
Keywords: Acceleration, back squat, fatigue, males and females, resistance trained, voluntary activation
