Maintenance of Skeletal Muscle Mass Does Not Guarantee Bench Press Performance: A Body-Composition Case Study

. In contrast, skeletal muscle mass changed only from 37.3 kg to 37.0 kg, lean body mass from 65.0 kg to 64.8 kg, and dry lean mass remained unchanged at 17.3 kg. Segmental upper-body lean mass also remained largely stable, with right arm lean mass changing from 4.13 kg to 4.07 kg, left arm lean mass from 3.99 kg to 4.01 kg, and trunk lean mass from 30.1 kg to 29.8 kg. This case demonstrates that maintenance of skeletal muscle mass does not necessarily preserve bench press performance. In this patient, marked loss of fat mass and total body size occurred alongside a substantial decline in maximal bench press strength, despite only minimal change in measured skeletal muscle mass. This was during a time period in which strength training occurred. These findings suggest that non-muscle mass and body geometry may contribute meaningfully to bench press performance and may help explain reductions in bench press strength during weight loss, even when lean mass appears largely maintained.