Interval Training Impacts Health Span

Living Well

Written by: Meg Sharp, Fitness & Wellbeing Consultant, Cambridge Group of Clubs

There’s lots of interesting advice these days on how to live longer. I’m far more interested in how to live better.

A recent paper cites that while life expectancy has increased by 3 decades in the last 70 years, health span has not enjoyed a similar expansion. The authors cite that the last 9 years of a person’s life – some refer to this as a marginal decade – is typically accompanied by chronic disease, disability, frailty, and poor mental wellbeing and cognition.

While this may be a common, it’s far from inevitable. My final decades are going to be some of my best. I’d like you to join me.

There are many ways we can ensure we thrive as we age. We can improve our physical, mental, and emotional health and fitness in the years leading up to our marginal decade. It’s a case of understanding and adopting behaviours that support these changes. An earlier start can allow us to build a larger physical and physiological reserve. And it’s never too late. The body loves a good challenge. 

Today we’d like to focus on aerobic capacity.

Aerobic capacity, sometimes expressed as peak oxygen consumption (VO2peak), is a robust predictor of improved health span. High aerobic capacity is directly associated with decreased risk of diabetes mellitus, cancer, obesity, hypertension, cardiovascular disease, and depression. Moreover, aerobically fit individuals enjoy more stamina and energy, exhibit less anxiety and stress, enjoy higher quality sleep, reduced back pain, improved cognitive function, lower risk of falling, and higher self-esteem. 

While 150 or 75 minutes of moderate – or vigorous – intensity exercise, respectively, every week is recommended to achieve the benefits cited above, high-intensity interval training (HIIT) is also effective with the added bonus efficiency and – for many – better adherence. There is also evidence to support that HIIT may be even more beneficial, separate from the boost that higher adherence would garner.

High intensity interval training is characterized by repeated, relatively short bursts of vigorous activity, interspersed with periods of rest or less exertion. Higher efforts are sustained for relatively shorter periods, and require more or lower intensity recovery or both. There are a million ways of creating effective protocols. The trick is to do something that requires you to work harder than you currently are. Go breathless. Recover such that you’re able to repeat the hard effort at least 4 times. Build from there by numbers of reps, duration, or intensity or rep or reducing the rest time. Do this type of workout at least once a week and no more than 3 times (for a highly trained individual).

The other key is, while all HIIT protocols will be uncomfortable, there is likely one type you will prefer. That little extra edge of “enjoyment” if you will, increases the odds you will keep doing it. The most important piece. Once you’ve got 4-6 weeks under your belt, try on a different protocol and see how it goes. Variety keeps the body adapting and growing and reduces risk of injury and boredom.

The Workouts:

I’ve listed some great workout ideas for you to try below. Remember to start each workout with some mobility, 5-10 minute warm-up and a cool-down. The longer intervals (more than 90 seconds) are typically doing something like running, cycling, walking uphill, or rowing. The shorter bursts (less than 90 seconds) are also great for those modalities, but you can switch things up using a jump rope, battleropes, boxing, kettlebell swing, sled, or another intense full body exercise, such a burpees, mountain-climbers, or lunge jumps! 

1 to 3: Go “all out” (Zone 5+) for 15 seconds, recover for 45. The recovery would be a slow spin, very slow row, or walking around. It’s better to recover moving than stationary! Repeat 4 times for beginners. Work your way up to 10!

1 to 1: These typically call for work in Zone 4 or 5, and can range from 60 seconds on/60 seconds off to (my personal favourite) 4 minutes on/4 minutes off. The longer duration taxes your mental strength as well. For the 60sec:60sec protocol, start with 4 reps and work your way up to 10.  For 4:4, start with 2 and work your way up to 4!

20/30/40: Go “all out” for 20 seconds then recover for 10. The 30 seconds on, 10 off, 40 seconds on, 10 off, and recover for a full minute. Repeat the cycle 4 times. Work your way up to 8!

Intensity Guidelines:

Note that using heart rate training zones have limitations. For example, cycling workouts will typically elicit a lower heart rate response for the same exertion compared to running workouts. Variables such as psychological stress, fatigue, and dehydration will also alter heart rate response, making it difficult to gauge how hard you are or more importantly should be working. As you continue to train, make notes of your heart rate and how you feel. You will be able to create a more accurate training table for yourself and may even find you notice you are able to work harder with a slightly lower heart rate than before. This change may be reflected in a decrease in your resting heart rate.

*HRR or Heart Rate Reserve:  The difference between your resting HR and your maximum HR (220-age for males, 226-age for females). 

Now calculate your training zones by adding RHR to a % of HRR.

For example, a 48-year-old female with a resting heart rate of 62 would have a HRR of 116 bpm (226-48-62).  This athletes Tempo Training HR Range is theoretically 156-166 bpm.

Sources

Coates, A.M., Joyner, M.J., Little, J.P. et al. A Perspective on High-Intensity Interval Training for Performance and Health. Sports Med 53 (Suppl 1), 85–96 (2023).

Garmany, A., Yamada, S. & Terzic, A. Longevity leap: mind the healthspan gap. npj Regen Med 6, 57 (2021).

Ito, S. High-intensity interval training for health benefits and care of cardiac diseases - The key to an efficient exercise protocol.   Int J Environ Res Public Health. 2021 Jul; 18(13): 7201.

Ketelhut S, Ketelhut RG, Weisser B, Nigg CR. Interval Training in Sports Medicine: Current Thoughts on an Old Idea. Journal of Clinical Medicine. 2022; 11(18):5468. https://doi.org/10.3390/jcm11185468

Atakan, M.M., et al.  Evidence-Based Effects of High-Intensity Interval Training on Exercise Capacity and Health: A Review with Historical Perspective.  World J Cardiol. 2019 Jul 26; 11(7): 171–188.