So, I started going to the gym about a month ago. Doing dumbell curls I started at 10lbs. I tried 50lbs at first.
Mistake!
Sized down until I got to 10lbs. I was looking for the first one I could do 20 reps. Then, as days went on, I kept moving up sizes. I'm currently at 25lbs. I keep wanting to move up to 30lbs, but my body gives way around the 12-15 rep range. So, not quite there yet. But the first 10 reps of 25lbs aren't even hard anymore. It only gets increasingly more difficult after the 10 mark, but more often than not the 15 mark. 15-20 are the hard ones.
But with 30lbs it's hard right from the start.
So, should I be doing the 30lbs reps, even if its less than 20 reps? Or do the 25lbs reps which I can easily do 3/4ths of before it becomes a struggle for the last few reps?
As low as 8 reps is effective. 20 is at the higher end but there’s some limited reasons to do that.
Multiple sets. 3 sets of 10 reps gets you 30 reps.
Give Renaissance Periodization and Jeff Nippard a look on the other platforms. Dr Mike talks a bunch about rep ranges.
....is it bad that I've been doing 5 sets of 20 reps? You're saying 30 reps total. If I REALLY pushed myself, I might be able to do that in 1 set. You're saying split it between 3 sets. Is there a such thing as too many reps? I've been just saying "nope!" if my arm gets this heavy/tired feeling. When I feel that, it becomes a struggle to lift, and I've been taking that as a sign that I need to rest before I get hurt.
No. It’s not bad. You’ll grow muscle. There is an upper limit for productivity. It won’t be as good for developing pure strength. It takes longer. It can be good for rehabilitating an injury, targeting a specific muscle, or managing fatigue.
You should target 2-3 reps in reserve. That means 2-3 reps before you literally cannot lift the weight.
If you’re doing sets of 20, it will be very difficult to injure yourself.