I used to be able to jog for 2 hours at a fast pace.
Now i jogged 20 minutes at a medium pace and was dead at the end of it lol.
I didn't feel healthy afterwards, it makes you realise how unhealthy people who only lift weights are.
Im going to build back up to 35 minutes and do it 3 times a week while also maintaining my weightlifting. Unless you are 300lbs juicer, running isn't really going to make you lose muscle lol.