Dissociated Time Course of Indirect Markers of Muscle Damage Recovery Between Single-Joint and Multi-joint Exercises in Resistance-Trained Men

de Camargo, JBB, Braz, TV, Batista, DR, Germano, MD, Brigatto, FA, and Lopes, CR. Dissociated time course of indirect markers of muscle damage recovery between single-joint and multi-joint exercises in resistance-trained men. J Strength Cond Res XX(X): 000-000, 2020-This study compared the time course of indirect markers of muscle damage after multi-joint and single-joint exercises. Ten resistance-trained men (years: 26.9 ± 3.0; total body mass: 83.2 ± 13.8 kg; height: 176 ± 7.0 cm; resistance training [RT] experience: 5.5 ± 2.4 years; RT frequency: 5.3 ± 0.7 sessions; relative squat 1 repetition maximum: 1.4 ± 0.3) performed, in a random order, 5 sets of 8 repetition maximum of the back squat (BS) and knee extension (KE) exercises. Rectus femoris muscle thickness (MTRF), leg circumference (LC), and muscle soreness (MS) were recorded at baseline (pre), 0, 12, 24, and 36 hours after each exercise protocol. There was a significant increase (p < 0.05) in dependent variables at every time point after both the multi-joint and single-joint exercise sessions. However, MTRF and LC were greater at 0 and 36 hours, and MS was greater at 24 and 36 hours after BS when compared with KE (all p < 0.05). This study shows that resistance-trained individuals can experience significant higher levels of indirect markers of muscle damage when performing a multi-joint lower-limb exercise compared with a single one.