Effect of downhill walking on next-day muscle damage and glucose metabolism in healthy young subjects.

This study aimed to investigate the effect of downhill walking on muscle damage and glucose metabolism in healthy subjects. All ten healthy young men and women (age, 24.0 ± 1.4 years) performed rest, uphill walking, and downhill walking trials. In the exercise trials, uphill (+ 5%) or downhill (- 5%) treadmill walking was performed at 6 km/h for 30 min. On the next day, muscle soreness was significantly higher in the downhill trial than in the uphill trial (P < 0.01). Respiratory metabolic performance did not differ between trials. However, carbohydrate oxidation was negatively correlated with plasma creatine kinase (r = - 0.41) and muscle soreness (r = - 0.47). Fasting blood glucose was significantly lower in the uphill trial than in the rest trial (P < 0.01) but not in the downhill trial. These observations suggest that downhill but not uphill walking causes mild delayed-onset muscle damage, which did not cause marked impairment in glucose metabolism. However, higher muscle damage responders might exhibit lower glucose metabolism.