As a personal trainer, I get asked this question all the time: “Is it better to perform fewer repetitions with more weight or more repetitions with less weight?” My answer is always the same: For general conditioning, you should use a weight heavy enough to fatigue your muscles after 10 – 12 reps. Keep in mind that as you get stronger, you will be able to do more reps with a given weight and will have to adjust accordingly.
Women in particular are often worried about “bulking up” if they use heavy weights, but this is just a myth. Unless you are lifting a REALLY heavy weight in the 2 – 4 rep range and drastically changing your diet (consuming large quantities of protein), this will not happen. Besides, as women our testosterone levels will not allow this. Sure, it’s possible for guys to bulk up and you see them all the time in the gym pumping heavy iron. But rest assured ladies, you will not turn out looking like the Hulk! If you prefer to stick to light weights, you can still get a good workout, but you will need to apply the same principle and do as many reps as it takes to fatigue your muscles. So if you are using light weights, this could mean you will be standing around doing 30+ reps of bicep curls for one set! Who has time for that? I would much rather see you grab a set of 10 or 12 lb dumbbells and do 12 reps and be done with it. Lifting heavier weights will give you the lean definition you are looking for because it will alter the shape of your muscles more quickly than using lighter weights. Plus, the more muscle mass you have, the more calories your body burns while at rest, and who doesn’t want that?
What about using your body weight for certain exercises vs. free weights or machines?
This is basically using heavier weights in disguise! It’s much harder to do triceps bench dips using your own weight than it is using 3 – 5 lb dumbbells to do triceps kickbacks. Also, it’s harder to do a regular pushup than it is to perform the equivalent exercise on a chest press machine. I like to alternate some body weight exercises with machine exercises or free weights during every workout to really challenge my muscles.
What size weights should I use in a Group class?
This depends on the class and what the instructor has planned. Usually, the instructor will tell the class to either grab light, medium or heavy weights; and sometimes a combination of all three. But in a typical group class you will be doing more repetitions than if you were working out on your own, so you may want to go one size down from what you use on the gym floor. Also, don’t be afraid to go over to the weight stack mid-class and grab another set of weights if the ones you have are turning out to be too light or too heavy.
To sum up… don’t be afraid to increase the amount of weight you’ve been lifting at the gym! You will get stronger faster, tone your body quicker and enjoy newfound self-confidence as you leave those teeny weights behind!