Muscle damage and soreness following a 50-km cross-country ski race

Abstract

In this study, we examined indirect markers of muscle damage and muscle soreness following a 50-km cross-country ski race completed in 2 h and 57 min to 5 h and 9 min by 11 moderately trained male university students. Maximal strength of the knee extensors, several blood markers of muscle damage and inflammation, and muscle soreness (visual analog scale: 0 = “no pain”, 50 mm = “unbearably painful”) were measured one day before, immediately after, and 24, 48, 72, and 144 h after the race. Changes in the measures over time were analysed using one-way repeated-measures analysis of variance and a Fisher's post-hoc test. Maximal strength of the knee extensors decreased significantly (P<0.05) immediately after the race (mean −27%, s=6), but returned to pre-exercise values within 24 h of the race. All blood markers increased significantly (P<0.05) following the race, peaking either immediately (lactate dehydrogenase: 253.7 IU · l⁻¹, s=13.3; myoglobin: 476.4 ng · ml⁻¹, s=85.5) or 24 h after the race (creatine kinase: 848.0 IU · l⁻¹, s=151.9; glumatic oxaloacetic transaminase: 44.3 IU · l⁻¹, s=4.2; aldolase: 10.0 IU · l⁻¹, s=1.3; C-reactive protein: 0.36 IU · l⁻¹, s=0.08). Muscle soreness developed in the leg, arm, shoulder, back, and abdomen muscles immediately after the race (10–30 mm), but decreased after 24 h (<15 mm), and disappeared 48 h after the race. These results suggest that muscle damage induced by a 50-km cross-country ski race is mild and recovery from the race does not take long.

Keywords:

• Isometric strength
• creatine kinase
• myoglobin
• aldolase
• C-reactive protein