This study examined the long-term effects of Taekwondo training on bone mineral density (BMD), body composition, and physical fitness in middle-aged men. Thirty men (43 ± 2 yr) were divided into three groups based on Taekwondo experience and current training volume. The currently practicing Taekwondo group (TKDC: n = 10, training career: 34.1 yr) practiced Taekwondo ≥ 2 times per week. The former Taekwondo group (TKDS: n = 10, training career: 19.2 yr) trained during childhood and adolescence, but ceased training before age 30. The control group (CON: n = 10) received no regular physical training during youth. The results showed that both Taekwondo groups had a significantly higher BMD, (p < 0.004) and Z-scores (p < 0.008) for femoral neck and L4 BMD (p < 0.023). For physical fitness, both groups showed significantly better results for 50m shuttle run (p < 0.001) and sit-ups (p < 0.0004) than the control group. No significant difference was found in body composition among the groups. In conclusion, TKDC and TKDS may have had site-specific benefits for BMD. As there was no significant difference in these variables between the two Taekwondo groups, the benefits were most likely gained during childhood and adolescence, and further training did not appear to increase these gains. More research is needed with a larger sample size to confirm these findings.