What happens to your body when you always lift the same amount of weight

The good, the bad, and the ugly.

Much like our breakfast of choice or how we wear our hair, most of us tend to gravitate to routine when it comes to our lifting workouts: We often use the same amount of weight, over and over.

No shame—it’s particularly comforting to select a weight size you know you can handle when you’re at the gym or in class (a.k.a. in front of people), and when you’re sweating at home, you may not have a variety of weights to work with. But experts say not changing your weight size means you’ll be missing out some pretty hefty bennies.

“When you train with the same weight week to week, over time, your body will adapt to the resistance, and you won’t see gains in muscular strength or hypertrophy [size],” says Jacque Crockford, a certified strength and conditioning specialist and exercise physiologist with the American Council on Exercise.

Compare it to running the same distance every time you hop on the treadmill—at some point, you’re not going to see your body improve, since you’re no longer challenging it.

That said, there is one important perk for those who don’t change up their resistance: muscular endurance. The term describes your muscles’ ability to produce force over a long period of time, and it’s crucial to intense and long-duration exercise, like a marathon. “Muscular endurance also helps us get through our busy days with more energy, better posture, and decreased risk of injury,” says Crockford.You’ll know if your muscular endurance has improved by how burnt out your muscles are during one set at your go-to weight. In other words, if you can handle 16 reps of, say, a shoulder press when formerly you could eke out only 12, then congrats—your muscular endurance is on its way up. Sticking with the same amount of resistance and increasing your number of reps is the best way to track that progress. If your goal is to look more toned, though, you have to go up in resistance, says Crockford. Crockford recommends the “2x2 Rule,” which basically means that if you’re able to lift two more reps than you intended during two consecutive training sessions, then it’s time to add weight. “Increasing by 5 percent is generally an appropriate rate of progression,” she says. If those middle-weight increments aren’t available, try the next-closest amount (so 12.5 pounds if 10.5 isn’t available).

Crockford adds that it’s important to keep your personal goal in mind when you’re strength training so that you format your workout routines accordingly. The American Council on Exercise recommends these rep/set counts. (It should go without saying that higher rep counts require lighter weights.)

General Fitness: 1-2 sets, 8-15 reps, 30-90 sec rest Muscular Endurance: 2-3 sets, 12 or more reps, 30 sec or less restHypertrophy: 3-6 sets, 6-12 reps, 30-90 sec restStrength: 2-6 sets, 6 or fewer reps, 2-5 min rest

And there you go! A reason to put a little more thought into your sweat sesh than you do your morning oatmeal.