re: Question regarding muscle loss

i would suggest moving to a 531 template with a 80% training max. my suggestion would be kryptea. Since you are below 10% i would suggest slowly doing a reverse diet...honestly using something like the carbon diet app would do you good.

then move to maintenance for a while too. then if you are comfortable slowly bump calories up.

keep protein high. in general though...you are not going to stay below 10% BF and add muscle. you are going to have to add BF to add muscle. is what it is.

on the lifitng....i would focus on movement and getting stronger/more explosive....track everything and adjust as needed.

5 days is a lot for someone getting older so be careful on there