The Strength Training Rules Just Changed. What a Movement Specialist Makes of It.
On March 17th, the American College of Sports Medicine published its first major update to resistance training guidelines since 2009. Seventeen years. That’s a long time in exercise science — roughly the same span that separated the first smartphone from the one in your pocket right now.
Most people will never read the Position Stand itself. It will filter down through doctors’ recommendations, magazine articles, social media posts, and word of mouth — often losing nuance or even accuracy at each step. So it’s worth taking a moment with the actual findings, because several of them challenge assumptions that have been repeated so confidently for so long that most people think they’re settled science and many will continue teaching from for years to come.
A few of these changes I’ve already been teaching around for decades. A couple are worth taking a moment to think about.
The prescription finally caught up with the person
The central shift in the 2026 update isn’t about sets, reps, or load. It’s about the goal of prescription itself. The ACSM is officially moving away from rigid, one-size-fits-all programs toward individualization — the idea that the most important variable isn’t your program design, it’s whether you’ll actually do it. The Behavioral Change Specialist in me loves this.
Stuart Phillips, a kinesiology professor at McMaster University and one of the lead researchers, framed it simply: “The best resistance training program is the one you’ll actually stick with.”
That sentence is doing a lot of work, and it deserves to be taken seriously. It means the research — 137 systematic reviews, more than 30,000 participants — is pointing toward something fitness culture has been slow to accept: enjoyment is a training variable. If you dread an exercise, the science now says swap it for one that produces a similar result and that you’ll actually show up for. There is almost always an equivalent option.
I’ve been telling students this for years. They ask me “which is better for me; yoga or Pilates?” and I always say “The one you like the most. That’s the one you’ll actually do.” Two exercises can produce the same training outcome (to be fair, these two are different, but complementary). One of them you like, one of them you don’t. That distinction determines whether you’re still doing it six months from now. The guidelines just made it official.
Training to failure was never necessary
This one matters, because “no pain, no gain” has been hammered into fitness culture for so long that many people genuinely believe discomfort is the point. The 2026 guidelines explicitly confirm otherwise: training to momentary muscular failure produces no better outcomes for strength, muscle size, or power than stopping 2 to 3 reps short of it. Stopping when you could still do a couple more reps is sufficient stimulus for adaptation.
That does not mean training is easy. It IS work — they don’t call it a workout for nothing. There’s a meaningful difference between the comfortable effort that produces real adaptation and pushing until form collapses and joints are under stress. The first is the goal. The second is how injuries happen.
In my classes, I cue what I think of as “comfortable effort” — you’re working hard enough to mean it, breathing with purpose, muscles fully engaged, but you’re not grinding. You finish a set with your form still intact and 2 to 3 reps left in reserve. For many students, especially those coming back after a break or managing old injuries, this reframe is a genuine relief. It turns out it’s also what the research supports.
This is particularly relevant for anyone over 50. Form breakdown under maximum fatigue is where injuries happen — and an injury takes you out for weeks or months. Consistent, well-executed training with effort left in reserve beats occasional all-out sessions followed by forced rest, every time.
Power training is now officially in the guidelines — and it’s probably what you need most
For the first time, the updated guidelines give explicit support to power training, and it produced the most consistent improvements in functional performance across the studies: walking speed, fall prevention, the ability to move through daily life with ease.
Power is not the same as strength. Strength is how much force you can produce. Power is how quickly. And for older adults, power turns out to be one of the strongest predictors of independence and quality of life. A 2025 Mayo Clinic study found that muscle power was a better predictor of long-term survival than muscle strength alone.
The good news is that power training doesn’t require a weight room or specialized equipment. The guidelines specifically mention fast chair stands and intentional step-ups as examples. In Pilates, we do a version of this in dynamic balance work — weight-shifting lunges where the goal is controlled landing and an intentional push back out. That combination of absorbing force and responding with purpose is exactly what power training looks like in practice.
Practicing power strength moves in studio is also a safe way to regain confidence lost. What the studies didn’t capture is what actually happens in the brain but I watch in class all the time. When someone who hasn't trusted their own legs in two years lands a lunge and returns to standing on one leg cleanly and looks up surprised — that's not in the data. The physical gains come first, and the confidence follows them. A safe, supervised environment gives people permission to practice failing small: a wobble, a weight shift that doesn't quite land, a balance recovery that turns out with a wobble but ultimately successful. That repetition of catching yourself — and being fine — is its own kind of training. The body safety mechanisms learns it's more reliable than it thought.
From nothing to something is the biggest gain
Across all 137 reviews, the most significant improvements came from one shift: going from no resistance training to any resistance training at all. Not from optimizing an existing program. Not from adding sets or increasing load. From starting.
The guidelines also confirm that meaningful results don’t require a gym. Elastic bands, bodyweight exercises, and home-based training produced clear improvements in strength, muscle size, and physical function. Twice a week, all major muscle groups. That’s the baseline.
For anyone who has been waiting for the perfect program before beginning, or who stopped during a busy stretch and hasn’t found a way back in, this is worth sitting with. The barrier isn’t finding the ideal plan. The barrier is starting.
If you’re interested in adding Pilates with resistance training to your life, try the New Student Special with me at the Yoga Center of Columbia.
