HIIT (high-intensity interval training) was recently ranked  the number one fitness trend in the American College of Sports Medicine’s 2018 worldwide survey. Little surprise to any of us who have been here a while.
People love high-intensity interval training because it’s a quick, efficient way to reap the same (or even greater) fitness benefits as a long, traditional cardio session—with generally less wear and tear, less physical stress, and (much) less time investment. It’s a core part of the Primal Blueprint approach to fitness and a consistent part of my own routine.
But I find it still intimidates beginners…particularly older men and women, those who have been inactive for years and those who are overweight.
Just a little refresher on the comparative benefits. The often quoted landmark 1996 study  comparing the effects of HIIT and moderate-intensity cardio found that performing HIIT five days per week was more effective for improving both aerobic and anaerobic fitness than performing traditional cardio five days per week. The HIIT workout from this study was eventually dubbed the Tabata protocol and consisted of alternating seven to eight 20-second sprints with 10 seconds of rest.
Since then, we know interval training is effective in less frequent schedules. A study  published in the International Journal of Obesity reveals three weekly HIIT sessions helped female participants lose as much as 7.3 pounds after 15 weeks. Meanwhile, moderate-intensity cardio led women to gain nearly three pounds over the same time period.
As for fitness gains, in one study , two weeks of sprint interval training, for a total of six sessions, were enough to increase muscle oxidative potential (resting muscle glycogen content) and aerobic endurance capacity in trainees. In a 2007 study , researchers discovered that the metabolic adaptations produced by low-volume sprint training are remarkably similar to those produced by traditional endurance training. Although long distance Chronic Cardio  has always been touted as the best way to improve heart health , another HIIT study  showed that sprint interval training is just as effective at improving arterial stiffness and flow-mediated dilation, two markers of endothelial function and helpful ways to predict heart health. And how about actual performance outcomes? Another study  found that low volume sprint interval training conferred rapid adaptations in skeletal muscle and exercise capacity – similar to those obtained via high volume endurance training.
If this is you, it might surprise you to know that HIIT is way more doable than you think it is. Doable doesn’t mean easy (interval training inherently needs to feel hard), but it does mean entirely attainable. Virtually anyone can make it work with appropriate transitioning.
Yes, those with heart conditions may be concerned that intense exercise will trigger a heart attack. Indeed, if you have a history of heart disease, heart attack or stroke, you’ll want consult with your primary care provider before starting HIIT or any exercise program. (You’ll also want to check with your doc if you have an underlying health issue such as diabetes, arthritis, hypertension or osteoporosis.) However, it’s worth noting that HIIT is considered a viable alternative  to moderate-intensity cardio in cardiac rehabilitation programs.
Perhaps you’re worried you simply won’t enjoy the intensity of HIIT? Consider this: When researchers  from the University of British Columbia tested the overall enjoyment level of moderate-intensity cardio, HIIT and sprint interval training (SIT) with 30 inactive adults, they found that the men and women ranked HIIT and moderate-intensity cardio as equally enjoyable. What’s more, 79 percent of the men and women went on to do HIIT on their own once the study was over.
The options for HIIT are practically endless. In fact, you can do an effective HIIT workout with low-impact activities. Remember, it’s the intensity of your efforts that separates your inclined walk or bodyweight exercises from a traditional workout. With HIIT, you’re working anywhere between 85 to 100 percent of your maximum heart rate, alternating short bursts of activity with brief recovery periods.
Ready to give HIIT a try? Assuming your doc gave you the go-ahead, here are a few ways to ease into HIIT.
Start With Equipment (If It Makes You Feel More Comfortable)
I’m not talking box jumps here. I mean the basic machines a lot of people identify with regular gym workouts. (While I think most are unnecessary in the long-term, they have a role to play for many folks.) Most HIIT studies use stationary bikes—for good reason. They’re a bit safer for the average person who’s working on mobility as well as fitness capacity to start out on a bike or elliptical or inclined treadmill or rowing machine than to suddenly max out on running. Look at the many alternative options . Purists don’t get extra points here.
Go For Multi-Joint Exercises/Activities
Moves that recruit a lot of different muscle groups will distribute the work more evenly across multiple joints than isolation exercises like biceps curls. Great options include squats, walking or jogging at an incline, push-ups (elevate your hands as needed), elliptical sprints, swimming, crawling, jumping jacks and walking lunges. Begin by using your bodyweight only and add light resistance when you’re ready.
Scale Back (and Up) When Needed
Burpees may be great for people who are already working from good form and solid fitness, but for others they can be a poor choice and ruin the whole endeavor just as these folks are getting out of the gate. Don’t be afraid to modify exercises as needed. If a workout calls for burpees, try omitting the push-up and the jump at the top. If you find jumping exercises (ex. squat jumps, jumping lunges, jumping jacks) hard on your joints, shorten the jump height so end up doing little hops instead. If you have a hard time lowering into a full bodyweight squat, only go as low as you can. As you gain strength and fitness, scale up the exercises.
Take things slow and easy—especially in the beginning. Start with one HIIT workout per week and build up to no more than two or three. It may take you a few workouts to get the hang of things, so don’t be afraid to slow your tempo and experiment with different exercises to find the most appropriate ones for your fitness level. How quickly you progress will depend on your current fitness level, the time you have available to train, and whether you have any underlying health issues. And remember, what works for someone else may not work for you. Listen to your body and progress according to your own timeline.
Thanks for stopping by, everybody. Who’s been putting off including an interval component in their workouts? I’d love to hear more about your concerns. And those who were hesitant but took on the challenge, how did you manage the transition? Have a great week.