I was out with a friend recently and the conversation turned to working out. She asked me how to know when it was time to increase the amount of weight she was using in her workouts and by how much. I thought other people might be wondering the same thing, so here goes. (These are general guidelines, but everyone's body is different. Listen to yours and don't do anything that causes you pain, dizziness or nausea. Consult a physician if you experience any of those things during exercise and before beginning an exercise program.)
There are formulas that they teach you when you study to become a trainer that are supposed to help you answer this question. But if you're anything like me, math is not your strong suit and you want a simple, practical method for figuring out when it's time to bump it up. Also, increasing weight by a percentage doesn't always correlate to the weights in which dumbbells or kettle-bells are available. So if you're lifting 5 pounds and want to increase by 10%, good luck finding a 5.5 pound dumbbell.
When I'm watching a client lift a weight, I can usually tell when it's too light or too heavy. There are universal facial expressions for too heavy :-) and I can tell a lot by how easily someone is swinging a dumbbell up during biceps curls, for example. There are also form cues. If a weight is too heavy, the body will often compensate by breaking form.
But if you want a general bit of advice here it is: when you can complete 12-16 repetitions of an exercise and you know you could knock out several more, it's probably time to increase. Another way of thinking about it is that when you're about 3/4 of the way through a set and you aren't feeling fatigued (like, "I can only do a few more" kind of tired), then it's probably time. I know my muscle is fatigued when I get to the point that I could not do one more rep in good form.
Other ways to know it might be time to lift something heavier is if you've been working out for a long time and never have done so, or if you have stopped seeing gains in strength. Muscles adapt to the demands you place upon them. If you want them to get stronger, you have to ask them to do more. Even if that means that instead of doing 12 repetitions of something, you can only do 8 in good form at the higher weight. Do 8 for a while and then add one or two more reps until you can do 12-16 again.
The experience of increasing the weight you lift can be a really empowering one! If you're working with a good personal trainer they know how to help you do that safely. But if you're on your own: research good form for the exercise you're going to try with the heavier weight. The American Council on Exercise has an exercise library with photos and cues for lots of exercises. You can access it here. And the first few times you do the exercise with the heavier weight, stand in front of a mirror and watch your form. Sometimes it's difficult to "feel" whether you're doing something right, so being able to see yourself can help.
See you here next week!