start now. Get a 2” piece of steel pipe that’s like 40” long. Put sling studs in it and walk around the block once in the morning and once at night. Then do the same thing with your backpack on. Then find a hill and do it. Then get a heavier pipe. Every step you take puts you in a better spot you were yesterday.I'm 32 and not in great shape, not bad shape. Average shape haha. I will always have this 300 bee. It's 1 of 2 guns I won't sell or trade.
At 32 you can be a destroyer of worlds with a little effort. Sets you up better for 42 as well.