When I was younger, I participated mainly in endurance sports and spent very little time devoted specifically to strength training. Yes I was doing some, mostly unaware that these were forms of strength training and as an outdoor athlete I shied away from what I deemed the gym junkie scene. As far as I was concerned the fitter aerobically I was, the healthier I was. Strength was a byproduct of my other training but not a conduit for well being.
Well that IS a very outdated view. Fortunately I found CrossFit or it found me, and my relationship with strength training changed.
In this blog, my goal is to encourage you to do some strength training on a weekly basis.
Already, a number of countries do include strengthening exercises in their physical activity guideline recommendations. This is driven mostly by the benefits to musculoskeletal health. But what about some of those other parameters we know are improved by aerobic conditioning?
We will look at a meta analysis article from the British Journal of Sports Medicine in 2022 which reviewed large prospective studies concerned with the effect of strength training on mortality, cardiovascular disease, cancer and diabetes. For those of you already doing some strength work on a weekly basis, you may be interested in how much appears to be a healthy volume.
First of all , what is defined as muscle strengthening exercise? Included in this definition are not only machine and free weight exercises (barbell, dumbbell, kettlebell etc) but also body weight strengthening ( air squats, pushups, pull ups, plank etc), other exercises where a load is pushed or pulled ( battle ropes, sled push or pull, medicine ball, sandbags etc), and even yoga, pilates or tai chi ).
Secondly, how good are the studies sampled in the meta analysis? The pooled numbers are good and most studies prospective. On the negative side is that there was not a large number of studies qualifying to be included, they often utilised self reported questionnaires to assess volume of exercise , and most were from only one world region- the United States.
Let's look at some specific outcomes from the study.
1. Muscle Strengthening and Mortality
Of 263 058 participants included, and 42 133 cases of all-cause mortality, muscle-strengthening activities were associated with a 15% lower risk of all-cause mortality.
2.Muscle Strengthening PLUS aerobic conditioning and Mortality
Of 581 194 participants and 68 637 cases of all-cause mortality, combined muscle-strengthening and aerobic activities (vs none) were associated with a 40% lower risk of all-cause mortality .
3.Muscle Strengthening and Cardiovascular Disease
Of 257 888 participants with 16 056 cases of cardiovascular disease, there was a 17% lower risk of cardiovascular disease in those who participated in muscle strengthening .
4.Muscle Strengthening and Diabetes
Of 202 486 participants with 9548 cases of diabetes, muscle strengthening activities were associated with a 17% lower incidence of diabetes.
5.How much time per week should you spend on strengthening? Can you do too much?
All these effects were non linear. That is, increasing time spent per week on muscle strengthening did not result in corresponding health effects. The maximum benefits in risk reduction for overall mortality, cardiovascular disease, and cancer were seen at 30 - 60 min/week of muscle strengthening activities.
For reducing the risk of diabetes this occurred closer to 60 min/week.
Performing more than 130 min/week of strength work resulted in a reversal of that risk reduction for mortality, cardiovascular disease and cancer. That trend was not as clear for diabetes.
What does this mean for you?
By adding about 60 mins per week of strength work ( eg 2x 30 min sessions ) to your regular aerobic activity, you can reduce your overall mortality, cardiovascular , cancer and diabetes disease risks.
Like everything we discuss, more is not necessarily better for health and so if you are already doing some strength work, limiting your total time focussed on this to less than 140 mins per week could be better for you.
If you need any help achieving your health and fitness goals and want to keep skiing, surfing, hiking or snowboarding as you get older reach out to Primal Regeneration . I offer Health Coaching specialising in these areas . My background as doctor, Primal Health and Fitness Coach, ski coach and surfer all contribute to my ability to help you on your journey.
