There’s long been evidence that moderate aerobic exercise (think walking, running, or cycling) is good for your lifelong health and well-being. Research even shows us more active people too tend to live longer and healthier lives with lower disease rates – including cancers, diabetes and cardiovascular disease.
But what about resistance exercises, like lifting weights? Although these types of exercises are thought to be probably equally good for health and longevity, there is less evidence showing the benefits. But a recent study now shows that 30 to 90 minutes of resistance training per week is enough to potentially reduce the risk of premature death from all causes by 10-20%.
The team of researchers from three universities in Japan conducted a meta-analysis – meaning they pooled data from 16 separate studies looking at longevity, disease risk and resistance exercise. This allowed them to watch tens of thousands of participants in total.
They found that 30 to 90 minutes of resistance exercise per week was optimal for reducing the overall risk of dying from any cause. More strikingly, they also found that regularly engaging in more than three hours of strength training per week could actually increase the risk of premature death by around 10%.
They also found that the optimal time spent in resistance training varied when it came to preventing different diseases. For example, while 40 to 60 minutes of strength training per week is optimal for reducing the risk of cardiovascular disease, the risk of diabetes continues to decline the longer a person devotes time to strength training. resistance every week. However, resistance training has been shown to have no effect on the risk of specific types of cancer, such as bowel, kidney, or pancreas.
The findings of this study are broadly in line with what the NHS already recommends. According to them, adults between the ages of 19 and 64 should aim to make two weight training sessions per week to benefit their overall health. But given that public health guidelines are often a compromise between what’s optimal to achieve and what people won’t be put off, it’s promising to see that the optimal amount of strength training per week to benefit to health mirrors current guidelines so closely.
There are some limitations to this study. Although the number of people included in the studies is large, the number of studies actually included in the analysis is still quite small. Study participants were also predominantly North American or Western European – so the results may not be as relevant for people of many different ethnic backgrounds. Another limitation is that most of the studies included in the review relied on questionnaires from large groups of people asking about their exercise habits. The problem with this is that people can overestimate or lie about how much exercise they actually get.
Optimal exercise
Strength training is good for your overall health in more ways than you might think.
Besides the evidence — that it makes you stronger, for example — researchers are beginning to learn more about the role that certain hormones and cells released during resistance exercise play in our bodies.
For example, myokines are hormones that our muscles release in response to all sorts of stimuli – including exercise. Circulating throughout the body, myokines are able to regulate metabolism, as well as liver, brain and kidney functions. A specific myokine that I have dedicated to studying in my career is myostatin. While we know that it regulates muscle sizethere’s all sorts of new evidence that it’s also influencing metabolism and growth of fat cells – all of which play a role in helping us stay healthy and live longer.
Research also shows us that resistance exercise releases tiny cell fragments from our muscle cells called “extracellular vesicles”. These allow our muscle tissues to communicate better with each other. Although we don’t know exactly what they do, we do know that they carry RNA (a molecule similar to DNA), proteins and even mitochondria (which help convert food into energy that our cells can use) of cell to cell. So while we’re still not quite clear on their function, this is just another reminder of the influence our muscles have on many aspects of our health and bodily function.
However, the authors of this recent study only looked at the relationship between strength training and longevity. That means they didn’t examine why it had a protective effect – and why more than three hours of strength training per week was also linked to a slightly higher risk of premature death. Although we are able to speculate why strength training has this protective effect based on what other research has shown, further follow-up studies will be needed to truly explore these questions.
But while this study showed that strength training was beneficial in preventing premature death from many harmful diseases, that doesn’t mean you should only do strength training. It’s important to also do moderate-intensity aerobic exercise (like walking, jogging, or cycling) most days of the week to maximize your chances of living a longer, healthier life.
