A lot has to do with your nutrition and how much rest you are taking overall.
When you are trying to gain weight, you need to progressively overload which allows you to build more muscle mass.
Ideally, I recommend lifting weights 3 times a week. Here’s why.
In order for progressive load to happen, you need to fully recover before you go for your next training session.
Now, I feel working out 3 times a week (which equates to roughly 3 hours) is not enough and one needs to stay active overall.
You have two options in this case:
I personally walk a lot and clock more than 50,000 steps a week. I feel this is the best form of aerobic training for 2 reasons:
1-You can easily think clearly and use this time to plan your day, set your goals etc, and at the same time get aerobic benefit. You can power walk if you wish to. Steve reeves (my role model) was a firm believer in power walking.
Steve Reeves—Power walking with a pair of light dumbbells.
2-Walking won’t interfere with your recovery, especially your nervous system. You see when you lift weights, you are not only training your muscular system but also your nervous system which takes a longer time to recover.
But if you love (this is the key word), doing cardio—like going for a jog, or do it on your favourite recumbent bike, by all means go ahead.
But limit it to 2–3 sessions for a total of no more than 90 minutes. This however depends on how good is your nutrition, how much sleep you taking everyday, genetics, and most importantly whether you are progressing in the gym or not.
Hope this helps.