How often you should be lifting isn’t a matter of finding an exact number. It’s about understanding your current priorities and choosing a frequency you know you can sustain. A decent program followed consistently will always outperform the perfect program rarely followed.

Focus On Recovery

You are not a spring chicken anymore. It may take you longer to recover from certain exercises than it used to. In our 20’s we can go to the gym 6-7 times a week even if we’re sore because we are just so resilient. As we get older, our potential to grow muscle declines, but that doesn’t mean our success has to.  

This goes for any age you are at. You shouldn’t be retraining a muscle if it is still sore. Focus on another muscle group, take a day off, or focus on mobility in weaker areas that day if that is the case.

Not Needing 6 Days A Week

Also realize, even if your goal is to look great, we don’t need 6 days a week to get there. In your 40’s you have way more obligations, and scheduling conflicts than when you were younger. So stop comparing yourself to then! We can all achieve the dream body we want with just 2-3 days of full body sessions a week. That really is all it takes. 

I didn't believe this till I tried it. I was so used to bodybuilding routines with body part splits and super high volumes and realized that is what I needed to grow. I did an article on The Best Muscle Growth Plan for Beginners that covers this. The research shows our muscles maximize the anabolic signal when hit properly with anywhere from 3-10 sets on a given muscle. After 48-72 hours, that signal goes back to baseline (in which case ideally, you’d want to hit it again to maximize it). If we know this to be true, then it doesn’t matter if you are 25 or 52, the guidelines still stand. You are better off taking your weekly volume per muscle, and splitting it into 2-3 full body days to maximize that anabolic signal for muscle growth. Keeping it all at just one day a week is inefficient.

What You Should Be Focusing On

While you are doing these full body routines, there are a couple things lifters over the age of 40 should focus on.

Form

I’d like to think one of the advantages to being over 40 now, is you are a little wiser than your younger self. Focus on proper form, and feeling the muscle working over ego lifting. There is no need to be moving the weight up if it isn't serving you. Focus on quality reps that work you through a full range of motion. This will minimize injury, and keep your mobility in check. 

Priming

Everyone should be priming. Whether you struggle to hit full range of motion, or are just stiff. Priming means choosing 3-4 mobility drills that cue up certain areas you have trouble firing. For example, if you can’t fire your glutes, you may do 2-3 sets of glute bridges before you start your squats. This will help wake up the nervous system to fire those muscles, so when you perform the squats, you will be able to do so more effectively and thus increase your potential to grow. Again, regardless of age I would recommend ALL lifters do this, we just know the 25 year olds won’t listen. You will. 

Listen to Your Body

Speaking of listening, find a pace that works for you. Choose a frequency, and intensity in the gym you can handle. You don’t need to be doing your 1 rep max in the gym anymore. In fact, research shows you can stimulate as much muscle growth by staying 2-3 reps shy of failure. If you haven’t been taking that approach already, do it now. This will still allow you to push the reps or weight each session, but also keeps you safely enough away from destroying your joints and causing an injury.

Health Over Performance

At the end of the day, going to the gym should be more about increasing your quality of life than anything else. You may have kids to keep up with, or just want to keep that vitality of youth. Choose a workout routine that increases that aspect more than anything else. Why risk deadlifting 600lbs when all you really want is to run around and play some sports with your kids? Really hone in on choosing routines that serve your overarching goal.