Grab a pair of dumbbells and churn out some bench presses. Chances are, your left arm (or if you’re a lefty, your right arm) will tucker out long before your dominant one.
“It is extremely common for people to have strength differences between their sides,” says Chris Powell, CSCS, celebrity trainer and DietBet.com game host. “In fact, it is more uncommon for our bodies to be perfectly symmetrical in size and strength than it is for them to be different.”
That’s no fault of your exercise routine. “While our gym workouts tend to hit both sides pretty evenly, when we go about our daily routines, we unconsciously use our dominant side far more than our weak side. This can be pushing or pulling doors open, rolling over to push yourself out of bed, or the side you always chose to take the first step onto the stairs,” says Powell. “While we wouldn’t necessarily consider this every activity ‘exercise,’ the more we repeatedly use one side, the more efficiently our brain learns to fire to those particular muscles. This results in stronger muscles on that side, and quite often larger muscles as well.” Also, if you’ve ever injured an arm or leg and had to baby it for a while, that might have something to do with any imbalances between your left and right sides.
“Most people go through life with these strength differences without even knowing or feeling a difference,” says Powell. “Usually it’s the exercise-centric folks—like you and me—that figure it out pretty fast.”
To shore up any weaknesses on one side or the other, Powell recommends opting for exercises that load each side of your body separately, such as dumbbell exercises—shoulder presses, chest presses, lunges, dumbbell rows, biceps curls, dumbbell squats, triceps extensions…. Unlike exercise machines and barbells, dumbbells don’t let your stronger arm or leg pick up the slack from your weaker one, he says. You can also try unilateral exercises, like single-leg lunges, single-arm shoulder presses, single-arm chest presses, and single-arm rows.
There’s no need to “even things out” by doing more reps on your weaker side, says Powell. Your weaker side will catch up naturally, since it will be forced to work harder.