Heart Rate Detraining: Use It Or Lose It?

Despite our best efforts to maintain a regular exercise program, life sometimes inevitably gets in the way and causes us to miss a workout or two, or maybe three or four. As exercisers, many of us want to know – how long can I go without exercising before my fitness levels decline and I start getting into heart rate detraining? And is all lost if I have to skip a week of workouts?

This post will cover the concept of heart rate detraining, “the partial or complete loss of training-induced adaptations, in response to an insufficient training stimulus” (Mujika & Padilla, 2000a). Essentially, we experience heart rate detraining when we either partially or completely cut back on exercise and - as a result - we experience a decrease in our fitness levels.

We use it, or we lose it (to some extent).

Finding consistent research on the details of detraining can be challenging because of the various research designs used in studies. However, there are some trends that we will share with you.

What happens when we detrain?

Two review articles of detraining literature by Mujika & Padilla (2000) delineate many of the physiological changes that occur with short-term detraining (less than 4 weeks) and long-term detraining (greater than 4 weeks). You can find those articles here and here.

Here are points we found interesting:

With short-term heart rate detraining, the following tend to decrease: VO_2max, blood volume, stroke volume, cardiac output, thickness of the left ventricular wall of the heart, and lactate threshold.

With short-term detraining, the following tend to increase: submaximal exercise heart rate, average blood pressure, and respiratory exchange ratio at maximal and submaximal levels.

So what does this mean? Basically, our body becomes less efficient at performing physical activity. Additionally, we tend to rely more heavily on carbohydrates, rather than fat, for fuel. Detraining has been shown to result in decreases in cardiorespiratory endurance, muscular strength, muscular power, and flexibility. These negative effects are seen to an even greater extent the longer we remain detrained.

How quickly do we lose our fitness?

That is going to depend on a variety of factors, including your age, training status before the detraining period, length of detraining period, and level of detraining (if you are cutting back or halting all exercise). Additionally, detraining may affect you differently than it affects someone else. Some research concludes that training adaptations may decrease at least somewhat in as little as two weeks, while other research demonstrates that many training adaptations may be maintained for several months.

We must also keep in mind that various components of fitness may be altered at different rates. This article by Berkeley Wellness suggests that aerobic fitness decreases more quickly than muscular strength.

Is there any hope for me if I have to stop exercising temporarily?

Yes, do not fret! Fitness losses due to detraining can be limited by training at high intensities before and during your detraining period, even when you must reduce your training frequency.

If you’re exercising consistently, you should see a couple high intensity days in which you were working in mostly the YELLOW or RED zones on your MYZONE Activity Calendar each week.

If you are in a period of detraining, you will not see as much data per week on your MYZONE Activity Calendar, but on the days you do exercise, try to spend some time in the higher intensity zones to maintain the adaptations you made when you were regularly exercising. Also, be sure to get back to a regular routine as soon as you can to avoid any further decreases in your fitness.

These recommendations are the same for older adults, who tend to have a harder time maintaining adaptations to training. For an older adult to maintain their fitness, they will likely need to exercise more regularly and avoid long periods of detraining.

What’s the takeaway from all of this?

Most of us will experience some period of heart rate detraining in our life. If you have a week or two of inconsistent workouts, don’t be too hard on yourself. Short-term heart rate detraining seems to result in minimal decreases in muscular and cardiorespiratory fitness. On the other hand, long-term heart rate detraining tends to result in more substantial losses in our fitness. If you experience an extended detraining period, try to get higher-intensity exercise in when you can.

Fortunately, MYZONE is here to reward us for our consistency and hold us accountable. Be sure to use your Activity Calendar to keep track of your workout schedule and the intensity of your workouts.

If you have questions about this article, connect with us on MYZONE’s Facebook page, Instagram, and Twitter. Be sure to use the hashtags #myzonemoves and #effortrewarded.

For more tips on how to use MYZONE to achieve your fitness goals, follow us for our Fitness Friday broadcasts on Facebook Live (subscribe on MYZONE’s Facebook page) every Friday at 8 am PT, 11 am ET.

Keep moving forward!

References:

Berkeley Wellness. (2014). The exercise detraining effect. Retrieved from http://www.berkeleywellness.com/fitness/exercise/article/exercise-detraining-effect

Bickel, C.S. (2011). Exercise dosing to retain resistance training adaptations in young and older adults. Medicine & Science in Sports & Exercise, 43(7), 1177-1187.

Fatouros, I.G., Kambas, A., Katrabasas, I., Nikolaidis, K., Chatzinikolaou, A. Leontsini, D., & Taxildaris, K. (2005). Strength training and detraining effects on muscular strength, anaerobic power, and mobility of inactive older men are intensity dependent. British Journal of Sports Medicine, 39(10), 776-780. Retrieved from http://bjsm.bmj.com/content/39/10/776.full

Lemmer, J.T., Hurlbut, D.E., Martel, G.F., Tracy, B.L., Ivey, F.M., Metter, E.J., …Hurley, B.F. (2000). Age and gender responses to strength training and detraining. Medicine & Science in Sports & Exercise, 32(8), 1505-1512.

Mujika, I., & Padilla, S. (2000a). Detraining: Loss of training-induced physiological and performance adaptations. Part I. Sports Medicine, 30(2), 79-87. Retrieved from http://link.springer.com/article/10.2165/00007256-200030020-00002

Mujika, I., & Padilla, S. (2000b). Detraining: Loss of training-induced physiological and performance adaptations. Part II. Sports Medicine, 30(3), 145-154. Retrieved from http://link.springer.com/article/10.2165/00007256-200030030-00001

Ratamess, N. (2012). ACSM’s foundations of strength training and conditioning (pp.159-160). Indianapolis, IN: American College of Sports Medicine.