Neuromuscular and Blood Lactate Response After a Motocross Training Session in Amateur Riders

BACKGROUND Motocross is one of the most popular motorized off-road sports, characterized by riding on irregular natural terrain of hard earth and/or sand with various obstacles throughout the course. OBJECTIVES This study evaluated the influence of a motocross training session on neuromuscular response and blood lactate in amateur riders. PATIENTS AND METHODS Nine motocross riders (22.7 ± 2.8 years) participating in amateur competitions at the state level conducted a training session of 20 minutes duration at a motocross track (1.6 km) with a 250-cc four-stroke motorcycle. Metabolic demand was measured with blood lactate concentrations before and immediately, 3, 5, 8, and 10 minutes after the training session. To measure neuromuscular response, riders completed handgrip strength and horizontal jump tests before and 10 minutes after the training session. Student's t-test and analysis of variance one-way repeated measures were used to compare the changes before and after the motocross training session. RESULTS Significant decreases in handgrip strength were observed for both hands (left: P = 0.010 and right: P = 0.004). However, no significant difference (P = 0.241) in horizontal jump ability was observed. Significant blood lactate values were observed immediately (P = 0.001), 3 (P = 0.001), 5 (P = 0.001), and 8 (P = 0.01) minutes after training when compared to the value before training. The peak blood lactate value was 6.5 ± 2.7 mM at 8 minutes after the training session. CONCLUSIONS Amateur motocross riders had significant anaerobic metabolism demands and had reduced handgrip strength following a training session. These data suggest an importance of physical training aimed at improving anaerobic and neuromuscular performance of the upper limbs in amateur motocross riders.