“How Many Reps Should I do?”

People want me to give them a magic number – if they always do X reps, they will look like a fitness model in just a few short weeks. It’s true that 4-6 reps is usually for bulking up while 12-15 reps is better for toning, but what’s missing here is any mention of the INTENSITY of the reps. That’s what causes the body to change and improve.

I tell people that they should not just shoot for a certain number, they should go for momentary muscular failure. Let me give an example – say you are interested in toning, so you want to do a 15-rep set. So you pick up a weight and do 15 reps then stop. Now ask yourself a question…. “Could I have done 16? 17? 18?” If the answer is yes, then you have just wasted your time. You didn’t get to momentary muscular failure. You should have kept going until you couldn’t lift the weight anymore.

I see a lot of people (women especially) who sit in an exercise machine, put the pin in for the first plate, lift the weight 30-40 times, then stop for no apparent reason. Then they yawn, take a drink of water, adjust their shoelaces, and twiddle their thumbs. Next, they do 20-30 more reps, set the bar down gently, meditate a bit, then walk over to another machine and repeat the same process. They never had to strain for a rep. They didn’t really work hard. Believe me, they have done nothing to help themselves. Nothing is going to change based on such weak sets.

If you find yourself able to do more than 15 reps, then next time grab a heavier weight! Light weight and high reps means muscle failure by 15 reps. Otherwise you’re doing TOO light and TOO many reps. You can work out like that every day and in a year – you’ll still look the same as you do now. By the last rep, you should be sweating, your face should be red, you should be gasping for air, and you should be just about ready to kill your Personal Trainer. If not, you might as well stay home, because you are just wasting time.

What works even better is to do “forced reps.” This means you go all the way to failure, then someone assists you just enough to crank out another 2-3 forced reps. All of my personal training clients will tell you from experience that this method gets them better and faster results than they could ever get working out in their own.

Clint Phillips is one of Chicago’s leading personal trainers.