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As you’ve probably heard, maximal training — whether via high-intensity interval training (HIIT), heavy weights, or sprints — does come with some impressive rewards, but there’s a lot of value at lower intensities, too.
“Submaximal intensity doesn’t mean submaximal results,” says Christopher Vo, the director of group fitness programming at Equinox. “In fact, you can achieve many of the same endurance, strength, and metabolic benefits as a HIIT class without the joint impact and with faster recovery times. It’s an approach that supports longevity, allowing members to train more consistently without burnout or overuse injuries.”
Maximal efforts inherently present more risk, Dalcourt adds. There’s the acute injury risk, for one, that comes with super difficult, taxing workouts. But if you’re doing too much high-intensity work without enough rest, you could also veer into overtraining territory (marked by increased fatigue and decreased performance and motivation, among other symptoms). Submaximal training not only comes with fewer of those risks but can also aid in recovery and muscle repair.
When it comes to strength training, sticking with submaximal loads also gives you a lot more flexibility. “If your load goes down, your degrees of freedom go up — you have more movement choice,” he says. Consider the way you can train with just your body weight (where you can twist, bend, and lean) versus when you’re lifting heavy weights (more rigid and no-nonsense). Taking your body through a greater variety of movement patterns provides more inputs for your nervous system, helping it become more intelligent, Dalcourt says. It also strengthens muscles in a more functional way (since we move in all directions in daily life) and trains your fascia from all angles. “When your fascia is strong omnidirectionally — meaning it’s strong in all dimensions — that’s when you get shape stability,” he explains. “And when you’re more stable, your muscles can actually produce more force.”
And in terms of cardio, submaximal training is a boon for your health from a longevity POV. Submaximal-intensity steady-state (SISS) cardio — where you’re working at a low- to moderate-intensity, hanging out in heart rate zones one, two, or three, and maintaining a relatively stable effort over time — helps to increase blood flow, build an aerobic base, train your cardiovascular system to be more efficient, and burn fat, Dalcourt says. This translates to a reduced risk of cardiovascular diseases and stronger heart and lungs, just to name a few of the benefits. Really, positive adaptations will even happen at the cellular level, where aerobic exercise even increases the number of mitochondria in the cell, he says, and protects and lengthens telomeres (which are an indicator of biological aging).
Not to mention, working at a submaximal intensity means you can exercise for longer and likely aren’t too destroyed to hit the gym the next day. This puts you in a better position to meet the Office of Disease Prevention and Health Promotion’s physical activity guidelines for Americans, which recommend adults get at least two and a half hours of moderate-intensity (or one hour and 15 minutes of vigorous-intensity) aerobic exercise every week. Research on more than 116,000 people published in the journal Circulation shows that meeting these activity guidelines reduces all-cause mortality by 19 percent and that getting between two and a half and five hours per week of moderate or vigorous physical activity seems to confer maximal benefits in terms of overall well-being.
Interestingly, the benefits follow a J-shaped curve; being sedentary poses the highest health risks, but on the other side, high doses of strenuous exercise can even reduce some of the benefits offered by staying active.
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If you enjoy high-intensity training, it can be hard to resist the urge to chase PRs or heart-pounding intervals. “The fitness industry — and even our own team — often leans toward creating the most challenging, sweat-inducing, fast-paced experiences,” Vo says. So if you want to reap the benefits of submaximal training, how do you ensure you’re not doing too much?
For one, you can look for classes like those found in Equinox’s Barre, Pilates, and Sculpt categories. “One of the newest additions, Rhythmic Sculpt, which launched earlier this year, is designed specifically around submaximal intensity steady-state principles, making it a prime example,” Vo says. These all fit the SISS training bill, eliminating the peaks and valleys of HIIT, and instead asking you to maintain a consistent, elevated effort while staying below the metabolic threshold — in other words, you’re never getting breathless, he explains.
That’s really the key to keeping cardio workouts at a submaximal intensity: staying under your anaerobic threshold, Dalcourt says. There’s no easy or perfect way to ID when you cross this line, but you can estimate it: the anaerobic threshold is considered to be at about 85 to 90 percent of your maximum heart rate (which you can roughly calculate by subtracting your age from 220). This loosely means that submaximal efforts will stay in heart rate zones one through three, while maximal intensities will have you in zones four and five. You can also use the talk test, Dalcourt says. When you’re working at a submaximal intensity, you should be able to talk; when you cross the threshold, you will not be able to say more than a few words without pausing to take a breath.
During strength training, it’s a bit simpler to keep your intensity in check — just don’t go super heavy. Submaximal strength training typically entails working under 80 percent of your 1RM, Dalcourt says. And if you get most of your strength training in during interval- or circuit-style workouts, make sure you’re getting enough rest between pushes so that your heart rate isn’t edging into zone four or five territory.
Caveat: This isn’t all to say that high-intensity training is evil and submax is king. The magic is in getting a mix so your body adapts to handle it all. “Submaximal training is great for a lot of reasons and should be part of your mix, but there's also room for maximal training within reason,” Dalcourt. “It’s about being very intentional about the inputs to the body so that we can build a system that’s highly adaptable and very healthy.”