The purpose of this study was to compare the fitness levels of healthy young Japanese adults based on the “old” and “new” sarcopenia versions of the European Working Group on Sarcopenia in the Older People (EWGSOP1 and EWGSOP2) and the Asian Working Group for Sarcopenia (AWGS 2014 and AWGS 2019) criteria. Sixty-nine Japanese young adults were evaluated using the diagnostic criteria and classification of sarcopenia (muscle strength, physical ability, and muscle mass). For both sexes, the percentage classified as “robust” on the sarcopenia diagnostic criteria was lower in “old” than in “new” classification. The “sarcopenia” category comprised 2% of females only, but none of them had “severe sarcopenia”. The proportion of participants with “presarcopenia” (old classification) was 19-38%, and that with “possible sarcopenia” (new classification) was 2% for females only. A higher proportion of healthy young adults were classified as “robust” in “new” compared to “old” because "presarcopenia" was eliminated in “new”. Moreover, since the proportion of low muscle mass exists in one-fifth of males and one-third of females, it would be difficult to use the new criteria to promote muscle mass gains and prevent from a young age to care for the future.

Tomohiro Yasuda