Yeah, it gets worse the older you get but it actually starts well before your 70's. If one doesn't start getting proactive by at least increasing their activity levels att a minimum (walks, bike rides, swimming, tennis, etc) then when you hit your 70's it can get very disabling. It's not a magic fix to take a testosterone supplement though, it has to be part of well planned exercise routine preferably weight training if one is seeking to increase or maintain muscle mass. The other activities I mentioned above are more for just reducing loss and maintaining muscle tone. I checked googl yesterday after I posted that and according to google the best supplement for a testosterone boost is Ashwaganda which allso helps with other things such as reducing stress and anxiety and helping to imporove sleep. It also has antioxicent and anti inflammitory benefits as well.I was told by the doctor that muscle mass really declines in your 70's. Getting a knee replacement means you lose leg muscles during recovery. Good to know.