This post was written by Mary Aschieris and brought to you by our partnership with Mighty Health, the first exercise and nutrition app specifically for people over 50.

As a mature (okay, over 50!) fitness enthusiast reflecting back over past decades, I can recall many popular fitness trends. During the ’70s it was all about running, nautilus, and the early days of Jazzercise. The ’80s and ’90s brought aerobics, step, and circuit training. Crossfit, pilates, and barre-style workouts are some favorite trends of the current millennium. The majority of this time, mainstream fitness training did not rely much upon a scientific approach. That seemed to be reserved mainly for the training of elite athletes. I am aware of this because I was one of those athletes. My sport was a very technical one, and we relied heavily on medical trainers, kinesiologists, nutritionists, personal trainers and coaches. During my 10+ years as a competitive athlete I learned hands-on how to gain a competitive edge using sports science and nutrition. But this was waaaay back in the ’80s, you know, when the dinosaurs roamed the earth! In the decades since, fitness research and fitness-related technology have advanced in leaps and bounds. Medical doctors also have a much better understanding of where fitness fits in the healthy aging of their patients. Most realize a combination of moderate to vigorous aerobic fitness with strength training helps to improve cardiovascular, muscular fitness, and overall health. In true aging-former-athlete form, I’ve since tried the above fitness trends plus many more. Some with great success, and some with great failure (I’m looking at you, spin class!). Surprisingly, HIIT (high intensity interval training) has become a favorite. I’m excited to share HIIT methods with you as it has become an important part of helping me reach my fitness goals.

What is HIIT?

High Intensity Interval Training has been around for decades, and has even made the top ten of the American College of Sports Medicine most popular trends since 2014. The combination of fitness technology colliding with challenges during the pandemic had HIIT trending as the ‘it’ exercise. The driving force was the need for efficient, low cost at-home fitness exercises. Today, HIIT is among the top five fitness trends according to a worldwide survey by ACSM. So what’s this craze all about and why is it touted as so beneficial to a health and weight loss program? Well, there is science behind the acronym, and a brief but deep dive will help clear up the mystery as to why it can be so beneficial to someone looking for an ideal way to improve fitness while losing weight. Interval training has been around for at least 100 years to improve stamina and strength. Top athletes have focused on ‘speed work’ to improve performance for decades. It’s a training method that has been popular with endurance athletes like runners, cross country skiers, and speed skaters. It’s a technique that helped Roger Banister break the four-minute mile in 1954 and many Olympians win medals. This is the foundation of what we refer to as HIIT workouts today.

The Science Behind HIIT

Studies on the short and long term effects of HIIT workouts appeared in the ’60s and ’70s and were improved upon in the ’80s during which real scientific data backed up the benefit of this approach to training. Data proved a correlation between short intermittent runs/pauses and increased metabolism. In 1997, research was published regarding the high intensity interval style workouts that created a buzz in the industry. It began when Dr Izumi Tabata was hired by the Japanese Olympic speed skating team coach to research the effects of high intensity interval training over a six-week period. The research involved a control group and a Tabata group each exercising five times a week. The control group worked out performing moderate exercise for one hour each day, while the Tabata group did so for much briefer amounts of time—and do I mean brief! They did an extreme type of HIIT workout ‘Tabata’ style: high intensity work for 20 seconds on, 10 seconds off for just four minutes each day. Comparing the two groups over the course of six weeks, the total amount of exercise was 1800 minutes of work for the control group versus 120 minutes for the Tabata group. The results were impressive: the Tabata group had a 28 percent increase in anaerobic and aerobic fitness levels compared to the control group! While the intensity needed for this type of workout is extremely high, similar results can be achieved when using low to moderate intensity over a slightly longer time frame.

The science behind high intensity interval training is that by alternating the intensity of a workout, you improve your anaerobic and aerobic performance. Anaerobic performance is reached when your heart rate works between 80-85 percent capacity. The formula to find your target anaerobic state is 220-your age multiplied by .8 (80 percent). With HIIT, you burn a lot of calories during your training, but there’s added post-workout benefits. There is an ‘after burn’ effect that is referred to as the excess post-exercise oxygen consumption (EPOC). This means you burn calories for about two hours post workout. During this time your body is using energy to restore itself to pre workout levels. During this period you basically become a fat burning machine. With HIIT, there are many pros:

  • Lose weight and belly fat
  • Lower cholesterol levels
  • Improve cardiovascular health
  • Improve muscle mass
  • Better insulin sensitivity

How To Get Started

HIIT—I’ll be the first to admit that the name can sound intimidating. But when you break down the acronym, ‘high intensity’ does not necessarily equal high impact. The type of cardio activities to reach a moderate to high level of exertion are different for everyone, so HIIT can be modified and adapted to meet you at YOUR fitness level. Using a 1 through 10 scale of perceived exertion, maintaining an 8 on this scale will help you reach maximum benefits in a low impact HIIT workout. Think breaking a sweat but still being able to converse. While this level of exertion can seem daunting, the briefness of it will help it be bearable. The second part of the acronym, IT (interval training) is the less intense recovery period: a 4 or 5 out of 10 on the intensity scale. This period brings you back to a more comfortable aerobic level. Both high and low impact HIIT workouts are great for losing body fat while gaining muscle and toning.

If you are just starting out, it is best to consult with your doctor to find the right level of intensity for you. You will likely discover it is best to start with low impact, low intensity interval training, or LIIT. Low impact moves such as lunges, squats, or push ups, and plank position are much easier on your hips and knee joints as they don’t involve jumping. You can achieve similar results with a 30-minute LIIT program as you would from 15 minutes of HIIT. With HIIT the work/recovery parts are typically equal (30 sec/30 sec), compared to LIIT, where the key is to keep the work periods slightly longer (40 sec) and reduce the amount of time for recovery (20 sec).

Home Workout Ideas

Try out this low impact HIIT workout with Mighty Health trainer Julie Diamond to get started on your fitness and weight loss journey with low impact HIIT or LIIT.

Take Home Message

The best workout routines are ones that can and will be done steadily over time, so while HIIT is an excellent workout and weight loss method, it will only be so as long as one is willing and able to go hard. The good news is that going hard for 20 second bursts can make 10-20 minutes be highly productive. It is equally good news to know that low impact versions of HIIT can be just as effective in helping you achieve your fitness and weight loss goals. It’s best to use this workout in conjunction with other physical activities that you most enjoy to develop a pattern that you will stick to. It’s so important to engage in exercise that has a positive effect on your stress level and mood. There are great resources out there that can help immensely and so can finding a great fitness app with low impact HIIT and training options that meet you where you are on your journey.

Mary Aschieris is a fitness and wellness consultant at Mighty Health. She has over 35 years of experience in the sports and fitness industry as a competitive collegiate athlete, a sports complex business owner, and a fitness instructor.

Read more from Mighty Health:

Say Bye-Bye to Flabby Arms

How Your Exercise Routine Should Change After 50


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