How to Handle HIIT When You’re Over 45

Can we truly prevent aging — not simply its signs (aka crow’s feet)? Researchers at the Mayo Clinic believe it’s not youth in a bottle that will help you get back to your prime, but rather youth regained through bursts of aerobic exercise — especially when you’re older.

Their study, published in Cell Metabolism in 2017, found that high-intensity interval training (HIIT), which integrates short bursts of intense aerobic activity into a longer duration of moderate-to-vigorous physical activity, actually reverses some aspects of aging on a cellular level.

“There are a multitude of benefits to HIIT, including improved lean body mass, improved insulin sensitivity, and, as the Mayo Clinic recently pointed out, improved mitochondrial function. You might remember from eighth-grade biology that the mitochondria are the part of our cells that produce energy; they’re the ‘powerhouses,’ if you will,” says Rob Sulaver, founder and CEO of Bandana Training and founding trainer at Rumble Boxing in New York City.

Sounds tempting, right? But before you enter the HIIT zone to access that younger you, you’ll want to understand HIIT’s fundamentals as well as gauge your current fitness level to avoid injury. Here, we breakdown how women over 45 should approach HIIT to reap the maximum benefits — and get their mitochondria back in fighting form!

First, Consult Your Physician

You look good, you feel good, so all’s good to start HIIT, right? According to Dr. David Hanawalt, PT, DPT in Chicago, the natural aging process brings about physical constraints that include decreased aerobic capacity, decreased spinal flexibility, lack of core strength, and balance issues that need to be considered prior to starting HIIT. “Joint cartilage can start to thin and degenerate by middle age, which could also lead to being less tolerant of impact activity,” he says. His advice: Always consult with your physician prior to starting a new exercise regimen to see what restrictions you may be up against.

Gauge Your Fitness Level

“When considering HIIT routines, you should be aware of your baseline fitness level,” says Dr. Theodore Shybut, a sports medicine expert at Baylor College of Medicine in Houston. “If you’re a novice, get input from an experienced coach or trainer before you set goals and expectations.”

Don’t know your fitness level? “As a general rule of thumb, you should be able to tolerate at least the same length of the class (45 to 60 minutes) performing a light cardiovascular activity, like biking, fast walking or the elliptical, without resting,” says Hanawalt. If you know your baseline fitness isn’t up to snuff (i.e., you don’t exercise ever), Shybut recommends starting with basic cardiovascular fitness, such as walking, biking, swimming, rowing, yoga, or Pilates, as well as light-resistance exercises, before progressing to HIIT. “Use your body weight and get comfortable with proper form before you ‘max out.’ For example, do step-up/step-down exercises before tackling box jumps. You have to walk before you can run,” he says.

There are a multitude of benefits to HIIT, including improved lean body mass, improved insulin sensitivity, and, as the Mayo Clinic recently pointed out, improved mitochondrial function.

Why all the caution? Many exercises in a HIIT program can be more advanced, such as plyometrics and other explosive, ballistic movements. Shybut notes that these exercises usually “require a strong base of fitness and training. These can be phenomenal exercises because of their intensity, utilization of different muscle groups and complex movements, but these are the kinds of workouts where the potential for injury [exists].”

However, even if you’re not feeling your strongest, Sulaver says you don’t need to nix the idea of HIIT altogether. “Lower-impact activities, shorter work intervals, longer rest intervals, and fewer sets are all ways to ease into HIIT,” he shares.

Find the Right Fit

HIIT group classes are hugely popular right now, but novices or injury-prone exercisers will want to “find a beginner’s class with a coach or trainer who can get you involved safely rather than join an advanced, competitive class,” says Shybut. If you’re unsure of the class’s intensity level, Sulaver suggests being honest with the instructor upfront. “It’s always good to give the instructor a head’s up — something along the lines of, ‘I’m just getting into HIIT training, and I want to be smart about this. Can you help me ease into it? Are there any modifications to moves or reps I can be mindful of?’”



Noam Tamir, owner and founder of TS Fitness in New York City adds that finding the right fit takes research. “Make sure to choose classes where the instructor or business has experience with older demographics,” he says. Often a quick phone call or scan of online client testimonials can clarify this for you. You’ll also want an instructor who teaches proper form. “Getting your movement assessed or asking the instructor ahead of class to inspect your form is always a good idea,” Tamir says. Finally, pay attention to the class size. “Take classes that are small in size so you can get personalized attention for your form not only before class but also throughout the class,” he says.

It’s Not a Race

Sprints might be a part of your HIIT class — but, when it comes to listening to your body, it’s not a race. Group settings can make you feel like you need to keep up, but there’s nothing wrong with knowing when you need to slow down. “You’ve got to give yourself permission to slow down a little bit and respect your own pace. You won’t be making much progress if you get injured,” says Sulaver.

When Tamir notices a client might be overexerting herself, he asks her to do the “talk test.” “If you can’t speak, then you’re overdoing it,” he says. Another way to measure pacing: Apply a scale of 1 to 10. “If you had to scale how difficult the workout is, and you are at a 9 or 10, you need to rest or slow down,” says Tamir.

Rest Is Key

If you hadn’t noticed, rest is essential to the success of HIIT programs. “If you don’t rest, you won’t be able to repeat the effort at the same intensity because your body will be too fatigued,” Sulaver says. “Give yourself permission to rest a little bit longer in the beginning so that you get comfortable working at a higher intensity; then you can progress from there.”

Of course, if something feels off, its time to take stock. “Know when to stop; severe pain should be a red flag,” warns Shybut. Though temporary soreness is typical in HIIT, the degree you experience should decrease as your body adapts to each consecutive workout.

“If your soreness is increasing or you’re experiencing joint pain, swelling, or instability, that’s a bad sign, and you should see a sports medicine specialist for evaluation,” Shybut says.

Our Pro’s HIIT Tips and Modifications

So you’ve decided HIIT is for you — now what? We asked our pros to lend their best tips to help you net success.


“Proper hydration helps with performance and fatigue. Drink some water two hours before class; this is the amount of time it takes to get into your system and work effectively for you,” says Tamir.

Build Up

“Start with lower-impact activities. As you feel more capable, you can graduate to higher-impact activities,” says Sulaver.

Mix It Up

“Doing some low-intensity exercises, like running, biking, swimming, or yoga, on the days you don’t do HIIT helps with recovery and will improve your conditioning,” says Tamir.

Listen to Your Body

“I tell my patients to listen to their bodies. If something doesn’t feel right, it’s your body’s way of telling you,” says Hanawalt.

Be Patient

“Change takes time,” says Sulaver.