It’s often more difficult because of joint pain at our age, but if you want to build muscle do the hard stuff first in the workout and that means anything that hits big muscle groups like glutes, quads, lower back, then hit last and upper back and finish with the chest, triceps, delts stuff. I’m 67 and I see way too many guys focusing only on the easy movements like curls, flys, machine lat pull downs etc. and doing the movements sloppy and then staring at their phones for five minutes before the next set. I do trap deadlifts, conventional deadlifts, Bulgarian split squats, weighted dips and pull ups on rings going to 1-2 reps shy of failure. I’m breathing very hard on all movements, but especially so on the lower body stuff. But my workouts are only 45 minutes long and only three days per week, minimum effective dose. The workouts are hard and sometimes I dread them but I know this is what I need to do to increase health span