The first week of my graduate school studies has been incredible! The experience of interacting with fellow students and instructors who share the same passion for Kinesiology is indescribable. I’m going to try bring a piece of that experience to you each week as I go over one of the many articles we review.
A majority of the graduate program is to review, analyze, and come up with research in the field of Kinesiology. This research then gets published for others to review, analyze, and publish their own. In other words, research begets research. If you’ve ever wondered why the ACSM recommends a specific protocol, such as the volume of exercise one should do per week, then you’ll find this particular discipline very interesting.
More specifically, the most recent literature published by the ACSM recommends people should accumulate 150 minutes of moderate-intensity per week or 75 minutes of vigorous-intensity per week. At first glance, these numbers may seem arbitrary. Where do they come from? How did we get to 150 minutes? Why not more, or why not less? And like many other researchers, they wanted to know the answers.
By reviewing articles and research publications, we can analyze the data that has been published by various studies that set out specifically to answer the vary question. For example, in this article, researchers hypothesized whether or not there was a relationship between exercise and likelihood of dying from health complications, such as atherosclerotic disease, cardiovascular disease, diabetes melitus, or hypertension. The aforementioned diseases will be referred to as all-cause mortality for the scope of this blog. In other words, what is the correlation between exercise and dying from health-related complications?
To answer this hypothesis, Lee et al. did a meta-analysis of 44 different publications relating to the the likelihood of developing (and dying from) diseases related to sedentary lifestyles (all-cause mortality). The results were astounding! There was a statistically evident dose-response when prescribing exercise to prevent all-cause mortality (Lee et al, 2001). In fact, most of the studies learned that the greatest response happened between no activity and some activity, reducing the likelihood of all-cause mortality by nearly 30% (Lee et al, 2001). In other words, the greatest reduction in all-cause mortality was seen in those who performed the minimum recommended amount of exercise (1000 kcal per week) compared to no exercise. Furthermore, the likelihood of all-cause mortality continued to decline in higher doses of exercise volume (1000-2000 kcal per week, and so on).
Although there is an immense amount of data to digest, all studies verified that there is an inverse relationship between dose response of exercise and all-cause mortality. Ultimately, this means that the more exercise someone performs, the less likely they are to die from the cardiovascular related diseases. It also means that the greatest benefit to exercise (in terms of reduction of likelihood) was seen between sedentary and minimum recommended volume. The takeaway? Performing as little as 1000 kcal of exercise per week has a monumental effect at reducing the likelihood of dying due to disease-related conditions.
This is why textbooks like The ACSM’s Resources for the Personal Trainer recommends exercise volumes of 150 minutes per week, or 75 minutes of vigorous intensity. The authors have compiled all of the data from thousands of studies confirming the same results. Over the years, these recommendations become more and more specific. For example, the article by Lee et al was published in 2001, at which time variables such as intensity, exercise accumulation (continuous exercise vs bouts of exercise), and frequency had not been accounted for. Therefore, researchers have decided to continue hypothesizing if those aforementioned variables would play a similar effect against all-cause mortality. Therefore, the most current recommendations include varying levels of intensity, as well as frequency, and bout accumulation as possible methods for improving the overall health of individuals.
At the end of the day, we now know this as inherent truth: exercise is medicine. Our role as trainers is to educate and influence the public health. But doesn’t it become easier if we know that even a minimal amount of exercise can have positive life-changing implications?
Tune in next week for another article breakdown!
Lee, I. M., & Skerrett, P. J. (2001). Physical activity and all-cause mortality: what is the dose-response relation?. Medicine and science in sports and exercise, 33(6 Suppl), S459–S494. https://doi.org/10.1097/00005768-200106001-00016
Medicine, A.C.O. S. (2017). ACSM’s Resources for the Personal Trainer (5th Edition). Wolters Kluwer Health. https://wolterskluwer.vitalsource.com/books/9781496391018