How much of a difference can strength and resistance training make to our future health?
It is well accepted that individuals who regularly perform moderate aerobic exercise tend to live longer lives with lower incidence rates of cancers, diabetes, and cardiovascular diseases (CVDs). However, what if cardio isn’t your thing? Many consider themselves fit even without a daily dose of 10,000 steps or regular cardio and instead practise some form of resistance training. Resistance or strength training refers to movements performed against resistance, commonly dumbbells, barbells, resistance bands or body weight. Strength training is increasingly popular, as exemplified by the Powerplay gym in the Stevenson building; you’re fortunate to find a free bench or squat rack on entry, and sometimes there isn’t enough room to swing well … a dumbbell. Resistance training has been recommended for musculoskeletal health. Still, its effects on premature death rates and disease risk were largely understudied until a study recently published in the British Journal of Sports Medicine.
Dr Momma and colleagues collated data from several previous studies to assess not only if resistance training affected mortality, cancer, CVD, or diabetes rates but also if the training duration affected relative risk. They found that 30 to 60 minutes of resistance training a week decreased premature death by 10-20%. The duration of resistance training that achieved maximum risk reduction varied for specific diseases. Strength training 30 minutes weekly lowers total cancer risk by nine per cent and an hour of resistance training weekly, decreasing diabetes risk by 17%. The risk of site-specific cancers such as colon, kidney, bladder, and pancreatic cancer were not associated with strength training.
The study also reported a “goldilocks effect” for resistance training on all-cause mortality, total cancer, and CVD risk. Weekly practising more than three hours of strength training increased the risk of premature death by about 10%. For diabetes, the risk continued to decrease beyond 17% after 60 minutes per week. The study concluded the effect of higher resistance training duration on mortality and disease risk is unclear. More research is needed to determine if there can be too much of a good thing in this case.
A secondary examination assessed the effect of combining strength training and moderate aerobic activities weekly benefits an individual’s health and longevity. The incidence risk reportedly decreased further when both resistance and aerobic exercise were regularly performed, such as 46% for CVD risk. However, the small sample size of the relevant studies compromised the quality of the data and was rated “very low” by the authors themselves.
There are a few limitations to keep in mind when contemplating the findings. As previously mentioned, the limited number of studies and participants restricted the quality of the statistical analysis. The authors scored and highlighted the data quality or lack thereof when appropriate. The included studies use interviews or self-reporting questionnaires to collect resistance training data; this is not ideal as people tend to overestimate the amount of time they spend exercising. Participants were predominantly North American or Western European. The findings, therefore, may not be as relevant for other ethnic backgrounds as previous literature shows that ethnicity is a factor in CVD and diabetes risk.
To summarise, to optimise your chances of living healthier for longer, a combination of regular strength training and moderate aerobic activity weekly seems the way to go. However, the motivation behind why and how we exercise is often multifaceted; goals can be short term oriented. The study highlights the importance of considering the impact of your exercise regime on your health for years to come.