It's different for everyone, depending on your genes and the current level of fitness that you're trying to maintain.
Generally, once a week is sufficient for me to maintain.
Once a week does it, huh? Are you old or young? Age might play a factor I guess. I don't know.
I'm 51, 5'10", 150lbs, and maintain what muscles I have going to the gym every 3rd day and lifting for 20 minutes or so. But I'm wondering if I can stretch that to every 4th day without losing any muscle (or gaining any fat).
Because maintaining much less than normal fat percentage, around 15 for men, is high maintenance. Meaning the amount of exercise and nutrition has to be precisely right. Fat is like a buffer for endurance energy usage and when that is low muscles are converted for energy and building blocks.
If you want to take it easy on lifting you might have to give up on your leanness a bit which is not necessarily a bad thing as long as you don't exceed the recommended level.
Once a week does it, huh? Are you old or young? Age might play a factor I guess. I don't know.
I'm 51, 5'10", 150lbs, and maintain what muscles I have going to the gym every 3rd day and lifting for 20 minutes or so. But I'm wondering if I can stretch that to every 4th day without losing any muscle (or gaining any fat).
I guess those numbers suggest your muscle mass is not on the high side. You can reduce your lifting frequency but should increase intensity. I think improving flexibility can help maintaining as you increase intensity. And keep the muscles lean for tennis.
The answer depends very much on your age. Loss of muscle mass accelerates for most men in their forties so "to maintain" becomes considerably more difficult.
Once a week is enough for me. I am 40. for some reason, I bulk up really fast, not sure if this is a good thing or not. When I bulk up too much , I lose way too much flexiblility and in tennis, flexibility is even more important than having the right muscles. Just ask Guga Kuerten. Skinny dude but VERY flexible and can hit huge.
and I used to think twice a week was good, but then I started getting more sore and injured from lifting than from playing tennis. that was annoying.
(Assuming you mean slim people and not lean as-in have deliberate body-building/beach body type leanness)Why do you think lean people need more effort to maintain muscle they already have?
I used to lift 2 to 3 times a week, but like some others have said, was constantly sore. When my shoulders starting continuously bothering me I decided to take the summer off and just play tennis period.
My game didn't suffer and the nagging soreness went away in time. That was 2 years ago. I haven't lifted with any regularity since, and prefer to hit the wall during the off season. I'm 64.
Back to the OP's question. For most people lifting once a week will easily maintain your strength.
It does depend somewhat on what sort of lifting you do though. You say you've never had muscle soreness after lifting - to me that's an indication you probably never push yourself past your comfort zone so noticeable strength gains are unlikely even if you're staying fit and helping keep the reaper at bay.
I didn't mean feeling sore/tenderness was needed, just that if you're training hard it's unavoidable to some extent/level. People who don't get it are usually not pushing themselves past their comfort point as much as they think they are.I lift to near failure every set, and have made muscle gains this way. I can't recall reading anywhere that feeling sore after lifting is either necessary or desirable for achieving gains. (I do realize that there is some delayed soreness when trying a new exercise, but that's different.)
I didn't mean feeling sore/tenderness was needed, just that if you're training hard it's unavoidable to some extent/level. People who don't get it are usually not pushing themselves past their comfort point as much as they think they are.
Everyone has a different ability to push past their zone and different idea of what that even means. IMO, if you're not pushing past and feeling the effects afterwards (the next day) to some level you're probably not going to see much gain either.
You said "I lift to near failure every set, and have made muscle gains this way" but your original post was about maintaining, not gaining.Wrong. Do some research, and you'll see that any sort of pain/soreness is not required to see meaningful muscle gains.
You said "I lift to near failure every set, and have made muscle gains this way" but your original post was about maintaining, not gaining.
Soreness isn't necessarily an indicator of a good workout - just to be clear - but if you're not getting it ever your routine has become far too predictable for your body so the gains will be immeasurably small if improving strength or endurance is the goal.
If you actually do lift to failure as you say, you're possibly failing too early or in such a metronomic routine you're not going to see gains even if you are maintaining what you've got (ref to op again). Most people think they're lifting to failure but aren't - they just have low expectations of their failure point (or can't be arsed).
The evidence of a varied and challenging workout is generally some mild soreness - same with playing too much tennis or going on a long bush-walk etc - you'll feel it in some way if you pushed it past a point of easiness.
Rarely do you achieve anything with workouts in terms of noticeable improvements without pushing past the point of comfort - and with that must come some level of exhaustion which requires recovery. Ask anyone who's ever anything in an athletic sense.
Your original post said the goal was to maintain what you've got. The answer to that is you don't have to work out that often really.