The fatigue of a full body resistance exercise session in trained men

Abstract

Objectives: We examined the fatigue and recovery for 48h following a full-body resistance exercise session in trained men.

Design: Experimental cross-sectional study.

Methods: Eight resistance trained men volunteered to participate (mean±SD; age 27.0±6.0 years, height 1.79±0.05m, weight 81.8±6.8kg, training experience 7.8±5.0 years). Fatigue and pain was measured before, after, 1h post, 24h and 48h post the full-body resistance exercise session, which was based on in-season models used in contact team sports (e.g. AFL, NRL). Other measures included maximal torque and rate of torque development, central motor output (quadriceps muscle activation, voluntary activation, H-reflexes), and muscle contractility (evoked twitch responses). Linear mixed-model ANOVA procedures were used for data analysis.

Results: Fatigue, soreness, and muscle pain did not return to pre-exercise levels until after 48h rest. Quadriceps maximal torque and muscle contractility were reduced from pre-exercise (p<0.01), and did not return to pre-exercise levels until 24h. Early rates of torque development and muscle activation were unchanged. The amplitude and slope of the normalized quadriceps H-reflex was higher immediately after exercise (p<0.05).

Conclusions: Full-body resistance exercise including multiple lower limb movements immediately reduced maximal torque, muscle contractility, and increased pain. While recovery of voluntary and evoked torque was complete within a day, 48h rest was required for fatigue and pain to return to baseline. Maximal voluntary effort may be compromised for lower-limb training (i.e. sprinting, jumping) prescribed in the 48h after the session.

Keywords: Fatigue; H-reflex; Pain; Voluntary activation.