HIIT-ing middle age

Thursday, January 18, 2018. Author Geraldine Campbell

HIIT-ing middle age - starting out your fitness journey later in life

Aging is a process none of us can escape.  Left unchecked, the aging process may lead to progressive increases in weight and reductions in physical activity, negatively affecting our fitness levels [1]. Fortunately, being habitually active throughout your life, in particular, having good levels of cardiopulmonary fitness (i.e., having a healthy and well-functioning heart and lungs) reduces the risk of health issues such as coronary artery disease and heart failure in later life.

Resistance training also prevents the loss of muscle and bone density that can occur with aging.  But what if you’re hitting middle age having been sedentary for most of your life? Is it too late to adopt a healthy, active life to gain the health benefits?

Do not fear…a recent study holds promise for you, even if you are starting your fitness journey later in life.

The study involved a large group of 45-65-year-olds who were sedentary but nevertheless healthy and free from illness. One group participated in a 2-year progressive exercise training program, while a control group undertook balance and flexibility training only. The aim was to explore whether the negative cardiovascular effects of a sedentary lifestyle could be reversed through exercise, and, if so, which specific component of exercise holds the key to better health.

The progressive exercise training program was fairly intense and involved:

  • A minimum of 30 minutes of exercise per session
  • 4-5 days a week
  • One High-Intensity Interval Training (HIIT) session per week
  • One resistance training session per week

Similar to competitive athletes, subjects progressed through distinct phases of training - a training technique known as ‘periodization’. Individuals in the exercise group passed through three phases: a preparatory phase, where exercises were gradually introduced; a peak phase with high-intensity interval training; and a maintenance phase to preserve newly acquired fitness gains.

After two years, the exercise training group experienced several fitness benefits, including:

  • Increased VO2 max - a measure of the maximum amount of oxygen your body can use in one minute and a good indicator of aerobic fitness
  • Increased left ventricular end-diastolic volume  - meaning your heart  pumps more blood with each beat so is more efficient at delivering oxygen and nutrients to exercising muscles
  • Reduced left ventricular and myocardial stiffness  - as we age, the stiffness of our heart walls increases, making it less effective at pumping blood and raising the risk of heart failure
  • Reduced heart rate at rest and during exercise.

Simply put, these benefits led to a more efficient cardiovascular system and subjects lowered their risk of poor heart health. Furthermore, the study suggests that the inclusion of HIIT seems to be the key to gaining these benefits. The HIIT sessions involved 4 minutes at 90-95% of your VO2 max followed by 3 minutes of active recovery, repeated 4 times. [3] 

The good news is that this impact of exercise training in middle-age (45-65) seems comparable to the effects seen in younger adults. Whether you’re in your early twenties or late fifties, you’ll still reap similar cardiovascular benefits from exercise.  The less good news is that, while exercise still remains massively beneficial for physical and mental health, positive changes to the heart’s stiffness and pumping ability start to tail off above the age of 65 [4].

So, taking advantage of your middle age years could be the key to healthy aging. You’ll be at reduced risk of heart failure, coronary artery disease, and several other conditions too. Even if you’ve led a very active life thus far, still look to still push yourself to increase in fitness; every little helps – a 1-MET (1 kcal per kg per hr) increase in cardiorespiratory fitness (aerobic capacity) is associated with reductions in all-cause and cardiovascular mortality by 13% and 15% respectively! [5]

Over 65? Keeping active is still very important and, even if you have to drop the intensity of exercise, you will still be doing your body and health a huge favor! [6]
It’s never too late to kick start your fitness journey! Progressing through our plans could be the perfect way to keep your fitness increasing without overloading your body initially. Our Get Fit Complete Plan could be just for you.

If you enjoyed this blog, please read my other posts:

Green exercise:  The hidden powers of your local park

Running Economy

What is hypertrophy?

What's the difference between fast and slow twitch muscle fibers?

Using fat for fuel

Food Cravings

Your lunch break is not just for eating. Upgrade it to a runch!

Resistance Band Training

Get to know your heart

How Alcohol May Be Limiting Your Progress

Running and Genetics


Genetic Dominance of East African and Jamaican Runners

Sprint and Power Performance

The Nordic Diet



[1] Redfield, M.M., Jacobsen, S.J., Borlaug, B.A., Rodeheffer, R.J. and Kass, D.A., 2005. Age-and gender-related ventricular-vascular stiffening. Circulation, 112(15), pp.2254-2262.

[2] Berry, J.D., Pandey, A., Gao, A., Leonard, D., Farzaneh-Far, R., Ayers, C., DeFina, L. and Willis, B., 2013. Physical Fitness and Risk for Heart Failure and Coronary Artery Disease Clinical Perspective. Circulation: Heart Failure, 6(4), pp.627-634.

[3] Howden, E. J., Sarma, S., Lawley, J. S., Opondo, M., Cornwell, W., Stoller, D., … Levine, B. D., 2018. Reversing the Cardiac Effects of Sedentary Aging in Middle Age—A Randomized Controlled Trial: Implications For Heart Failure Prevention. Circulation

[4] Fujimoto, N., Prasad, A., Hastings, J.L., Arbab-Zadeh, A., Bhella, P.S., Shibata, S., Palmer, D. and Levine, B.D., 2010. Cardiovascular effects of 1 year of progressive and vigorous exercise training in previously sedentary individuals older than 65 years of age. Circulation 122(18), p.1797.

[5] Kodama, S., Saito, K., Tanaka, S., Maki, M., Yachi, Y., Asumi, M., Sugawara, A., Totsuka, K., Shimano, H., Ohashi, Y. and Yamada, N., 2009. Cardiorespiratory fitness as a quantitative predictor of all-cause mortality and cardiovascular events in healthy men and women: a meta-analysis. JAMA 301(19), pp.2024-2035

[6] LaMonte, M.J., Buchner, D.M., Rillamas‐Sun, E., Di, C., Evenson, K.R., Bellettiere, J., Lewis, C.E., Lee, I.M., Tinker, L.F., Seguin, R. and Zaslovsky, O., 2017. Accelerometer‐Measured Physical Activity and Mortality in Women Aged 63 to 99. Journal of the American Geriatrics Society

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