We ask GP and personal trainer Dr Hazel Wallace for the science behind exercise and find out if it really is the key to living longer.
The New Scientist calls exercise ‘the best medicine’, while the Academy of Medical Royal Colleges hails it as a ‘miracle cure’. But why is exercise so effective at helping us live healthier for longer?
Dr Hazel Wallace is part of an emerging group of doctors who believes that prescribing lifestyle advice alongside traditional medicine could make a huge difference to our health. In her latest podcast series, she consults with the specialists to discuss the transformative power of exercise on everything from our mental health to how fast our body ages. Here, we ask her for the science behind our biggest questions.
Why exactly is exercise so good for us?
“I see a huge need for prescribing exercise to prevent and treat lots of different diseases,” says Dr Hazel Wallace. “It’s not just effective for our cardiovascular health. Being physically active reduces your risk of breast and colon cancer, osteoporosis and also mental health-related problems such as dementia and depression. There’s even a place for exercise when dealing with more severe mental health issues such as post-traumatic stress disorder.”
Can we really exercise ourselves younger?
Exercise officially reduces our risk of early death. “Regular exercise helps to keep everything inside us a bit younger – from our organs to our muscles and bones,” says Dr Wallace.
“An important study by scientists in Taiwan found a strong relationship between physical activity and mortality or risk of disease. Even those who exercised for 15 minutes a day had a 14% reduced risk of all-cause mortality and a three-year longer life expectancy. That said, we encourage 150 minutes of exercise each week, as this offers the greatest benefits.”
Even better, the least fit people get the greatest results, according to Dr Wallace. “Don’t worry about where you start; you have the most to benefit. Once you start exercising, you’ll enjoy the steepest curve of health gains.”
What happens to our brain when we exercise?
In the short-term, most of us experience ‘runner’s high’ or a feeling of euphoria after working out. “We know that exercise stimulates the hippocampus and prefrontal cortex in the brain, both of which are involved with learning, memory and attention. On a more subjective level, it also does wonders for our self-esteem. It gives us an instant sense of gratification and achievement, which has the power to lift our mood and make us feeling amazing,” she says.
“In the long-term, exercise can also change your brain in a chemical and physiological way. Once we reach 30-40 years our brains start to shrink, which is a normal part of aging. However, we know that regular exercise slows this down.”
Which exercises are most effective when it comes to our mental health?
“I think a combination of aerobic and resistance training is likely to have the biggest impact on our mood.” Dr Wallace suggests this is because both exercises increase blood flow to the brain. They also require us to be more mindful and methodical. “Exercise gives us the excuse to have some me-time and focus on our ourselves, which can be quite rare!”
A recent study published in the journal Lancet Psychiatry looked at the impact of certain types of exercise on mental health. They asked participants how many days in the previous month their mental health was ‘not good’ due to stress, depression or problems with emotions. The result was those who ran or cycled fared 19% better than those who didn’t exercise. Those who did yoga or tai chi reported a 22.9% reduction in poor mental health days, while those who played team sports such as football and basketball reported 22.3% fewer.
How does it help us to fight stress?
Exercise acts as an anti-inflammatory and this in turn can help with chronic stress. “Acute inflammation is the body’s natural response to dealing with something that it perceives to be harmful. However, if we lead particularly stressful lives, have a really poor diet or suffer from a chronic condition, then this low-grade inflammation over months or years can be damaging”.
Are short bursts of exercise really that good for me?
Unless you’re an athlete or training for a goal such as a marathon, little and often could come with the most health benefits. “If you’re finding it hard to fit the exercise in, try building it into your daily routine,” recommends Dr Wallace.
“A group of researchers from New Zealand and the UK recently coined the term ‘exercise snacking’, which means fitting exercise in as often as you can throughout the day – whether it’s playing with your kids, running up the stairs or going for a brisk walk before dinner. After looking at two groups of type 2 diabetics, the researchers found that those who did three 10-minutes bursts of exercise throughout the day, compared to those who did 30 minutes all in one go, had better control over their blood sugar levels.
“Not only do we have to think about moving more, but sitting less,” explains Dr Wallace. “If you do exercise in the morning, but sit down all day and don’t do anything else, you’re not getting all the benefits from exercise.”
Is it ever too late to start exercising?
The recommended NHS guidelines (150 minutes of moderate aerobic activity and two sessions of strength exercise) are still the same for adults over the age of 65. “If you are generally fit and have no health conditions that limit your mobility then it is safe to exercise until any age,” says Dr Wallace. “Though if you’re ever worried, always speak to your GP.”
“As you get older, muscle-strengthening exercises become increasingly important for your bone health – particularly in women who are going through or have gone through the menopause. These can be body weight exercises you can do at home – whether it’s squats, push-ups against the wall or doing dips on a chair.”
“To all my older patients, I always recommend carrying the shopping bags, doing the gardening and pushing your grandchild’s pram. Or lift anything that is a little bit difficult for you to. Exercise has no age limit!”
A final word…
As a nation, we all want to be more active and adopt healthier habits, according to Dr Wallace. We’re more likely to take up exercise than give up smoking according to a study published in the British Journal of Sports Medicine. But it needn’t be a drastic, unfathomable change. “I know if I can inspire anyone to move a bit more, sleep a bit longer and eat a bit better, it has the potential to make a big change to their health.”
Want more advice for living longer? Check out our 9 proven ways to be happier and healthier in older age.