Physical activity with high intensity causes an increase in the concentration of lactic acid in muscle and blood which becomes an indirect marker of fatigue. This study aims to prove the effect of far infrared (FIR) radiation using the sauna method on fatigue and muscle damage in athletes after submaximal physical activity. This research method uses the quantitative with a randomized pretest-posttest group design. The research subjects were 21 male pencak silat athletes aged 18–23 years. Subjects were randomly divided into three groups with differences in FIR radiation time of 45ºC, group 1 radiation recovery for 10 min, group 2 for 20 min, and group 3 for 30 min. The three groups were treated with submaximal physical activity of 85% maximum heart rate by running on a treadmill, then recovery with FIR radiation. Data collection on blood glucose levels (BGL), blood lactate levels (BLL), and malondialdehyde levels (MDAL) immediately after physical activity (pretest) and after recovery (posttest). There was a significant decrease in BLL from all groups after recovery (p < 0.05). The greatest decrease was found in group 3 (Δ =  − 2.300 ± 1.661), group 2 (Δ =  − 1.7571 ± 0.91807), then group 1 (Δ =  − 1.129 ± 1.036). But no significant difference was found in BGL and MDAL. Based on the results, FIR was effective for recovery from fatigue indicated by a significant decrease in BLAL and a decrease in BGL. FIR was not effective in preventing muscle cell damage, as seen by no significant decrease in MDAL.