What Counts as Strength Training?

The verdict is in: Strength training is essential for long-term health. Mobility, balance, muscle mass, metabolic health, body composition, bone density, even straight-up longevity — these health markers (and more) get a special boost from resistance training.

But what, exactly, counts as strength training? The answer might seem simple — obvious, even. Conventional fitness wisdom tells us that lifting heavy weights counts, while everything else is just cardio or stretching.

But this belief only scratches the surface of how muscles are challenged and strengthened.

“The first thing to consider is What is strength?” says Life Time trainer and strength coach Daniel Espinosa, BS, ALPHA. “That’s the muscle’s ability to produce and resist forces.”

Consider the example of putting a 30-pound child into a stroller. First your muscles produce force to hoist the child off the ground; then they resist it as you set the child into the seat.

Without some measure of strength, you wouldn’t be able to move at all. But only certain movements push the limits of your muscles in a way that allows you to maintain — or even increase — that strength.

Strength training, then, “is a form of exercise that systematically challenges your body’s ability to produce and resist force,” Espinosa says.

Lifting weights is an effective way to train this ability. But ­multiple forms of body-weight training, like calisthenics, yoga, and martial arts, also work. Variable-resistance ­modalities, like reformer Pilates, cable machines, and resistance bands, are other good options.

More important than the tool, say experts, is the challenge.

“Barbells, kettlebells, calisthenics — these are just methods,” says Mark Schneider, NASM-CPT, a Twin ­Cities–based personal trainer and owner of the Retreat Strength Gym. “If you’re doing more than before, with a method that builds your ability to generate force, you are doing strength training.”

The question to ask yourself, then, is not What counts as strength training? but, rather, Am I challenging my ability to produce and resist force?

Hard and Heavy, Slow and Steady

When you’re building strength, it helps to understand a training concept known as progressive overload. Its guiding tenet is that slowly increasing the stress of training triggers the body to adapt and grow stronger. “Stress” and “slow” are key here.

Stress: This is the “overload” piece of progressive overload, which teaches that training stress is a requirement for change. This holds true for any ­activity: Whether you’re training to run a marathon or compete in powerlifting, improvement requires finding and nudging the edge of your ability.

Slow: Measured and intentional increases in training stress, combined with sufficient recovery, can yield the safest and most sustainable results. Again, explore the edge of your ability each time you train. This, rather than blowing past your edge and risking injury, is what makes progressive overload, well, progressive.

“Effort is the catalyst in strength adaptations,” says Ashley Thomas, a group fitness instructor for Life Time who teaches the reformer-based class CTR (Core. Tone. Reform.). Still, an ­effort that qualifies as overload is highly individual. It depends on your current level of strength and fitness.

If you haven’t exercised in many years, or you’re recovering from an illness, just standing up out of a chair a few times might work your muscles enough to make them stronger. If you’re already fit, however, performing three sets of 10 body-weight squats might not be enough overload to stimulate growth and improvement.

What’s easy for one person might overload another, and what overloads you today might not do so after two months of consistent practice.

“Over time, you will be able to gradually increase the demands you’re placing on your muscles,” says Life Time personal trainer and barre instructor Danica Osborn. This, in turn, should render you stronger than before.

Lifting Weights and Beyond

Lifting is commonly associated with strength training, and for good reason.

Using an external load in the form of free weights or machines allows you to overload your system incrementally and for a long period of time. You can safely challenge your strength and nudge your edge using a variety of techniques.

“You can lift the weight faster; you can increase the sets you perform, take less rest time between sets, or adjust many other variables,” says Osborn. Other tweaks to consider include adding weight (even as little as 0.25 pounds), doing more reps per set, adding a tempo, or playing with movement variations.

“As long as you keep challenging your muscles in some way, you’ll continue to make progress,” she says.

Lifting weights makes it easy to objectively track improvements in your strength and ability. “You can enjoy a lifetime of progress,” says Espinosa. That progress will almost certainly slow down over time — the more advanced the lifter, the slower the gains — and you may reach a point in your training where maintaining, rather than gaining, strength is the goal.

Weight training may be the most efficient route to strength, but it’s not the only way. Most yoga classes consist of postures, or asanas, that activate muscles. Hiking, running, and biking — especially over challenging terrain or up and down hills — can stimulate some lower-body strength gains. Pilates, especially when performed on spring-loaded resistance equipment, such as a reformer, can potentially trigger progressive overload.

For beginners, almost any exercise or movement builds some strength, because everything requires a novel level of effort.

Keep in mind that you may eventually become too strong for these activities to keep making a difference.

The best tool, ultimately, is the one you use. Over a long career of working out, you may want to experiment with more than one — or possibly all — of them. Just remember: The key to getting stronger in the long term is not the tool you use but the way you use it.