I've been hitting the gym 4 days a week for strength training, but I'm worried I'm not doing enough cardio. My goal is to get leaner while keeping muscle mass. Should I add cardio on my rest days or is that overtraining?
I've seen this play out with people around me who are serious about fitness, and the answer really depends on what kind of cardio you're talking about. Light stuff like walking or easy cycling on your rest days won't hurt recovery - in fact, it can help with blood flow. But doing intense cardio sessions on top of heavy lifting 4 days a week means you need to be careful about total volume and calories. If you're eating enough to support both, you'll be fine. If you're in a deficit trying to lean out, adding hard cardio might cannibalize muscle because your body can't recover from everything.
The sweet spot for most people is 2-3 cardio sessions per week alongside strength training, and you can spread those however works. Some folks do 15-20 minutes after lifting, others do full sessions on separate days. Since you're already lifting 4 days a week, adding one dedicated cardio day plus some light activity on a rest day would probably get you results without overtraining. The key is tracking how you feel - if you're constantly wrecked or your lifts are stalling, dial it back. But one extra day of moderate cardio is nowhere near overtraining for most people.
You're not necessarily underdoing it - four days of strength work is solid, and you don't need to go crazy with cardio to get leaner. Light to moderate cardio on rest days is fine if you want it, but honestly the real lever for losing fat while keeping muscle is your diet and not overdoing the volume. If you're eating right and recovering well, you could do 2-3 cardio sessions a week on top of your lifting without issues - doesn't have to be on rest days, could be right after lifting or whenever fits. The key is listening to your body and not tanking your recovery, which kills both strength and muscle retention.
The stuff that's worked for me is keeping cardio short and lower-intensity on rest days - like 20-30 minutes of walking, swimming, or easy cycling - which actually helps recovery without eating into muscle gains the way longer intense sessions can. A practical thing most people skip is doing like 5-10 minutes of moderate cardio *after* lifting instead, since you're already there and it doesn't interfere with recovery the way rest day cardio sometimes does, plus it fits naturally into your routine without adding another gym trip.
Adding 2-3 sessions of light cardio on your rest days won't hurt - it actually improves recovery and keeps your deficit modest rather than aggressive, which helps preserve muscle while you lean out. Just keep it genuinely easy; if you're huffing and puffing, you're eating into recovery from the lifting.
Log into answer.
