Physical activity appears to be a strong determinant of the building of peak bone mass and the degree of bone mineralization in young adult males. This study aimed to describe the impact of volleyball (V), throwing athletes (TA), climbing (CL), snowboarding participation (SN), fracture history, hand grip strength (HGS), and body composition on forearm bone mineral density (BMD) in males. BMD, bone mass content (BMC), and T-score of the distal (dis) and proximal (prox) parts of the forearm were measured by the DXA technique. The CL and TA groups showed the highest BMD, BMC, and T-score dis and prox. In the TA group, a higher prevalence of normal BMD was found in the distal part of the forearm compared to V (by 6.7%), CL (by 15.4%), and SN (by 35.7%). In the CL group a higher prevalence of normal BMD was found in the proximal part of the forearm compared to V (by 12.4%), TA (by 6.8%), and SN (by 34.6%). The highest prevalence of low bone density was observed in the SN group. Covariance analysis revealed that body height and the type of sports competition significantly affected BMD in the distal region (adj. R = 0.77). For BMD in the proximal region, the significant factor was sports competition (adj. R = 0.73). In both the distal and proximal regions of the BMC, the significant factors were handgrip strength (HGS) in newtons (N) and the type of sports competition (distal adj. R = 0.60; proximal adj. R = 0.85). Similar results were obtained for the T-score dis. The T-score prox was significantly affected only by HGS (N) (adj. R = 0.59). Training based on throwing and weight-bearing exercises influences higher forearm BMD. The results of the study also highlight the important role of information about past fractures, which may serve as an initial indicator of risk groups for low bone density.