Interestingly, while in some sports, being over 25 years of age is considered over the hill. However, in sports such as bodybuilding and powerlifting some pros don’t reach their peak until their mid 30’s or even 40’s.
Josh Lowndes and his colleagues from the University of Central Florida, Orlando, have revealed that age had little impact on the capacity to build muscle in adults aged 18-40 years of age.
Possibly some aspects start to change a little as you enter the 5th and 6th decade of life. That is, the magnitude for out right growth does appear to diminish a little. However, the mechanisms for muscle growth are still in place right up until our 90s. So to me, the limitations for age-related muscle gains appear to be due to the gaps in research (lack of studies) more than clear fact. Just keep pumping iron!
Source: Journal of Strength & Conditioning Research, 2009.
