According to the World Health Organisation, non-communicable diseases (e.g., cardiovascular diseases, cancer, type 2 diabetes) are responsible for almost 70% of deaths worldwide. The increase in non-communicable diseases is mainly attributable to four major risk factors: smoking, excessive alcohol consumption, poor diet and physical inactivity.
Read also: Our article about the impact of 5 lifestyle factors on life expectancy
According to an international consensus, a sedentary lifestyle is defined as any waking activity that takes place in a sitting or lying position. This includes all activities where the energy expenditure is less than or equal to 1.5 METs. The MET is a "metabolic equivalent", an arbitrary unit that corresponds to your energy expenditure sitting in front of the television without talking. Sedentary behaviour should not be confused with physical inactivity. Physical inactivity implies that a person does not meet the World Health Organisation's (WHO) minimum recommended physical activity targets. For health benefits, it is recommended to spend at least 150 minutes per week doing moderate intensity activities (between 3 and 6 METs, i.e. 7.5-15 METs-h/week) or at least 75 minutes of high intensity (above 6 METs, i.e. >15 METs-h/week). This means that in order to follow these health recommendations, you can do for example 5 sessions of 30 minutes running (6.5 km/h corresponds to 6 METs) per week or 3 sessions of 25 minutes running at 10 km/h (10 METs). In addition, you should do at least 2 muscle strengthening sessions per week.
Read also: Our article about physical activity and mortality
Regular strength training helps to increase and maintain muscle strength and mass. And like VO2MAX, it has already been shown that muscle strength is inversely correlated with the risk of all-cause mortality. However, does resistance training have an impact on the risk of non-communicable diseases? If so, what is the minimal dose of strength training to achieve significant health gains? Is there a maximal dose that should not be exceeded? And can we expect additional benefits from combining resistance training with cardiovascular endurance activity?
In an attempt to answer these questions, a team of Japanese researchers carried out a meta-analysis of 16 studies involving between 3809 and 479 56 participants, followed for a median period of 25.2 years. The participants (women and men) ranged in age from 18 to 98 years. All the studies were specifically concerned with resistance training (in all its forms: body weight or with additional loads), but not with physical activities where heavy loads can be occasionally moved (eg, gardening). In addition, some studies also combined cardiovascular activity. The researchers investigated the relationship between weekly resistance training and health problems including all-cause mortality, cardiovascular disease, cancer and specific cancers (colon, kidney, bladder, lung and pancreas) and type 2 diabetes. Information about participants' practice was collected either by questionnaire (13 studies) or by interview (3 studies).
The main results of this study show that resistance training is associated with a reduced risk of all-cause mortality, and specifically with mortality from cardiovascular disease, diabetes and cancer. Furthermore, the maximum risk reduction (between 10 and 17%) was associated with strength training for 30 to 60 minutes per week.
All-cause mortality
Seven studies including 263 058 participants looked at all-cause mortality. During follow-up, 42 133 deaths occurred. Resistance training reduced the risk by 15%. The optimal dose appeared to be 40 minutes per week, with no benefit observed after 140 minutes per week.
Three studies (581 194 participants and 68 637 deaths) investigated the benefit of combined resistance training and cardiovascular endurance. The risk of all-cause mortality was reduced by 40%.
Cardiovascular diseases
Seven studies (257 888 participants and 16 056 cases) showed that resistance training reduced the risk by 17%. The optimal dose appeared to be 60 minutes per week, with no benefit observed after 130 minutes per week.
Three studies (582 672 participants and 15 643 cases) investigated the benefit of combined resistance training and cardiovascular endurance. The risk of cardiovascular disease was reduced by 46%.
Cancer
Six studies (540 543 participants and 21 253 cases) showed that resistance training reduced the risk by 12%. The optimal dose appeared to be 30 minutes per week, with no benefit observed after 130 minutes per week.
Three studies (585 930 participants and 17 212 cases) investigated the benefit of combined resistance training and cardiovascular endurance. The risk of mortality from cancer was reduced by 28%.
In addition, resistance training was associated with a 10% reduction in the risk of lung cancer. No association was observed between resistance training and a reduced risk of colon, kidney, bladder, or pancreatic cancer.
Diabetes
Five studies (202 486 participants and 9 548 cases) showed that resistance training reduced the risk of diabetes by 17%. The optimal dose appeared to be 60 minutes per week, with a slight improvement as the hourly volume increased.
Resistance training is associated with a lower risk of all-cause mortality and with a lower risk of mortality from the major non-communicable diseases: cardiovascular disease, cancer and diabetes. This risk appears to be associated with an average weekly exercise time of 30-60 minutes. However, the shape of the curves (in the form of an inverted U) suggests that exercise of more than 130-140 minutes per week would have no health benefit and could even increase the risk of mortality...
These surprising results can be explained mainly by two points: the first is that the weekly volume and type of practice were reported via questionnaire and interview. It is known that there is an overestimation as well as imprecision when people are asked to indicate the type of practice, the intensity, the duration and any other important detail to have a real idea of the physical activity performed. The second point is that the number of studies was relatively small and the researchers were not able to carry out further analyses on specific fringes of the participants (e.g. according to level of exercise).
In addition, all the studies showing health benefits of strength training follow training programs with more than 2 weekly sessions, regardless of the audience. More studies are therefore needed to draw clearer conclusions about the long-term benefits (or not) as a function of dose and intensity.
We remind you that you can quote articles by limiting your quotation to 200 words maximum and you must include a nominative link to this one. Any other use, especially copying in full on forum, website or any other content, is strictly prohibited. In doubt, contact us.
Copyright © 2011-2024 - www.sci-sport.com - All rights reserved
Facebook
Instagram
Twitter
Flux RSS
Newsletter
YouTube