This is a common question, so I thought I would answer this for you. Let me start by defining some terms for you. A repetition (rep) is the amount of times you perform an exercise. A set is collection of reps that ends in reaching muscle failure (or close to it). Muscle failure is when it becomes impossible for you to perform another repetition using good form due to the build up of lactic acid. A rest interval is the amount of time you rest between sets. An active rest interval is when you perform some other activity like jumping jacks, jump rope, etc. during the rest interval between sets. (I’m particularly fond of this, because I want to avoid standing or sitting around while I’m working out).
So how many reps and sets should you do? It all depends on what you are trying to accomplish. If you are trying to build strength, then you want to do 5 to 8 repetitions (reps) and 1 to 3 sets per exercise. If you are trying to build endurance, then you should do 1 to 3 sets of 15 to 20 reps. If you want to build power, then only do 3 to 5 reps with very heavy weight. Basically, if your goal is to create muscle or enlarge the muscle (the term for this is called muscle hypertrophy), then your rep range should be 12 or under. If you want to avoid building and only work toward toning, then you should do higher reps in order to challenge the endurance. If you are working toward building endurance, then keep the rest intervals low – between 30 seconds to 1 minute. When lifting heavier with fewer reps, the rest interval should be anywhere from 1 to 4 minutes depending how heavy you’re lifting.
How do you choose your weight? When just starting out, I don’t recommend going to all out “muscle failure”. I suggest you choose a weight that will allow you to do the designated amount of reps with good form, but not go to muscle failure. After about a month, try to push yourself to muscle failure. You should seek to increase your weight in small increments from workout to workout. Most lifters go by “feel” to determine how much weight to lift. It could change from day to day depending on your energy level. Although it is never advised to do a 1 rep max test, a general “ball park” number is that you should lift anywhere from 55% to 85% of your 1 rep max (which is the amount of weight you could lift with good form only 1 time).
Okay, I have a special note for women. Please read this carefully: DON’T BE AFRAID TO LIFT TOO HEAVY!! I can assure you that you won’t bulk up unless you have a very unusual body type and way too many male hormones. The only reason men bulk up is because of the abundance of testosterone, which we fortunately do not have. Make sure you lift heavy enough to cause you to reach or get close to muscle failure by the end of the set.
Now, for you men, don’t lift so heavy that you compromise your form. I’ve seen it way too many times at the gym… you try to lift really heavy in order to impress your friends or the women. By the way, I’m on to you, so I’ve never been impressed by that. If you are compromising your form in order to squeeze out a repetition, then you are setting yourself up for injury. Make sure you learn proper weight lifting techniques for each exercise.
I hope this helps you and gives you some guidance with your weight training. For more information and articles, please visit my website at www.fitnessforwomeningeorgia.com.