What is the best exercise for you?
Time is always tight, and there are so many fitness fads out there: from hot yoga to high intensity interval training, what is best for you?
"Everybody knows that physical activity is beneficial, but not everybody knows how difficult it is to achieve behavioural change, how we need to individualise it, how we need to be able to help people explore their own reasons to be physically active," says Dr Wilby Williamson, consultant physician in sports and exercise medicine and assistant professor in exercise physiology at Trinity College Dublin.
Whatever activity you choose, the most important thing is to move: sitting time is associated with mortality from all causes, including cancer. Let that sink in. It’s just sitting, but it’s potentially life-threatening.
In general, the more active you are, the better, but small increases in physical activity can have a pretty dramatic impact on your health. For example, the biggest decrease in risk of death by any cause is seen in sedentary people who take up 30 minutes of daily activity – such as walking. Just like that, with that small change, their overall risk of death by any cause drops by 20 per cent. Further increases in physical activity mean that your risk continues to drop, but now you need to do a lot more in order to achieve a significant decrease in risk. In summary, the biggest beneficial change occurs when you get off the couch and start moving.
There is plenty of evidence for the good that physical activity can do for your health: it can decrease the risk of cardiovascular disease, diabetes, obesity, hypertension, cancer, bone and joint diseases. Although many other factors contribute to these diseases, not doing enough exercise is usually the most prevalent one, and one that can easily be changed.
How does exercise improve our health?
So physical activity helps us live longer, but how? For starters, it helps us maintain a healthy weight, and reduces the proportion of our bodies that is made of fat, while also helping control sugar levels in the blood. It also improves our heart and brain health by increasing heart function and reducing blood pressure.
Many chronic ailments like cardiovascular disease and diabetes are associated with low but persistent levels of inflammation in the body, which can be measured as increases in the levels of chemicals such as C-reactive protein in the blood. Exercise can decrease the levels of these chemicals, and the fitter you are, the more inflammation is reduced and with it the risk of developing chronic diseases.
Studies have shown that exercise can decrease the risk of developing cancer
It is easy to see that exercise is good for your heart and your muscles, but studies have also shown that it can decrease the risk of developing cancer. How does physical activity do this?
As it happens, in many ways. Firstly, obesity increases the risk of as many as 13 cancer types, so exercise leading to weight loss can definitely be protective. Aside from this, repetitive exercises have been shown to reduce cell proliferation, activate genes that suppress tumours and even promote the death of cancer cells. Physical activity is also known to stimulate the function of the immune system, increasing its cancer-fighting abilities, while exercise can also change the circulating levels of hormones in the body (for example the female hormone oestradiol in postmenopausal women), leading to lower risk of developing breast cancer.
There is strong evidence that moderate and vigorous physical activity lowers the risk of seven types of cancer: colon, breast, kidney, endometrium, bladder, liver and stomach cancer, as well as oesophageal adenocarcinoma. The reduction in risk may seem low (between 10 to 27 per cent, depending on the cancer type), but it is actually large for a preventive measure. There is also more limited evidence for a protective role of physical activity on blood cancers such as leukaemia and cancers of the head and neck, pancreas, prostate and ovary. Surprisingly, extremely fit people have a 27 per cent higher risk of melanoma, or skin cancer; this probably relates to a greater amount of time spent outdoors in light clothes, and highlights the importance of wearing sunscreen when you’re out and about.
Finally, physical activity can really improve your mental health. For elderly people, having stronger hearts and muscles means more mobility and independence, which translates into better quality of life. More generally, physical activity is associated with reduced symptoms of anxiety and depression: this is partly because exercising can distract you from what’s causing your symptoms, but also because physical activity releases endorphins, chemicals similar to those found in cannabis. The combination of relief from vicious worrying cycles and the feel-good molecules in your blood seriously increases your well-being, and if you add the social component – such as playing sports with a team or running with a buddy – then you’re on to a winner.
It is important to note that all of these benefits come from routine physical activity, so going to the gym once sadly does not mean you’ve gained a few extra years. Keep it going!
That’s all very well, but what’s the best type of exercise?
“That’s where it becomes challenging, because often trials are designed around focused interventions . . . and measure very specific outcomes,” Dr Williamson says. So studies rarely measure the specific effects of individual sports, and when they do they might not measure important factors such as social engagement and well-being. Also, studies that explore the effects of specific sports often include very targeted study populations: for example, studies around football are usually carried out in young people, while older adults are usually enrolled in studies to evaluate the benefits of Tai chi. These biases make it really difficult to determine what the broader benefits of sport are.
“There is a richness of data,” says Dr Williamson, “but most trials are around physical activity and cardiovascular health, or targeting specific disease groups, so it’s then difficult to say, what about if we look specifically at football?” He also points out there is a lot of gender bias in these studies, with the vast majority of them focusing on males.
In general, physical activity of any intensity is good for you, but more intensive activity gives you more benefit for the same amount of time. “There is a dose-response effect: the more vigorous the activity you’re doing, the more beneficial effects you see,” Dr Williamson says. However, he points out that intensive exercise also carries a bigger risk of injury, so always be careful not to overdo it, and incorporate warm-up and warm-down into your routine.
Different types of exercise have different benefits: for example, aerobic exercise (see box for definitions) is better than strength building exercise at keeping our arteries healthy, but a combination of both is the best approach to keep a healthy weight. Meanwhile, any type of exercise – aerobic, strength or a combination of both – helps control sugar levels in diabetic patients. So how to choose?
“[The] good thing is one size doesn’t fit all, so everyone can explore their personal preferences and still benefit,” says Dr. Williamson. “But the benefits might be slightly different when we compare individuals.” He also believes gender, socioeconomic factors and availability of sporting facilities need to be taken into account when choosing a ‘best’ exercise.
The one-size-fits-all approach doesn’t work because different people have different goals: some types of exercise are better for weight loss than others, but that may not be what you want. Other exercises are good for strength building, but maybe you just want to improve your cardiovascular health. Or maybe you want to expand your social life, and pedalling on your exercise bike while watching Corrie is just not going to cut it.
It's not just about starting something, it's about sticking to it
“Narratives around physical activity are perceived as being something quite simple,” Dr. Williamson says. “Ah, sure, you just need to get out and do a bit more and then you’ll be healthier! Ah, come on now! . . . The reality is a lot more complex.”
Most importantly, it’s not just about starting something, it’s about sticking to it. So ultimately the best type of exercise for you is the type you’ll keep at, whether because you really enjoy it, because it suits your schedule, or because it comes with a dose of nature or social interaction, or all of those things. Keep in mind that mixing different exercise types means getting several benefits at once, while reducing the risk that you’ll get bored on your first day.
And last but not least, it is definitely easier to integrate physical activity into your life if you start at a young age. The vast majority of children in Ireland do not achieve the minimum recommended exercise levels (73 per cent of boys and 87 per cent of girls aged 10-12 years, and 85 per cent of boys and 91 per cent of girls aged 12-18 years). "With current rates of obesity and physical inactivity in Ireland, we are potentially altering the life-course trajectory of our kids," says Dr Williamson, highlighting that we're failing our children.
He believes that physical activity for the prevention of diseases such as cancer or dementia needs to start early in life. “That doesn’t mean that people who are already suffering from chronic diseases cannot benefit from exercise, but the gains are different.”
“We can see how this [sedentary behaviour all tracks into hard endpoints that are often a burden within our health system – dementia, heart failure, cardiovascular disease, falls, but actually this is on potentially predictable trajectories and starts from early in our childhood. So if we’ve got [that] only 15 per cent of our kids are physically active at age 14, then we’ve got decades of accumulation of sedentary behaviour and lack of physical activity, so they might start having less resilience to risk factors, they might start accumulating more cardiovascular risk factors, and then the risk for disease might start coming in earlier in the life-course.”
“And because of our successes in modern healthcare we’ll be able to treat their diabetes and manage their cardiovascular disease, but they’ll have a higher burden [of disease] and less quality of life, so their disease-free years go down, and we really don’t want that.”
Whatever works best for you, make 2020 the year when you choose to make one small change for the better.
Types of exercise
When you can feel you're getting warm, your heart beats faster and you're a bit out of breath, but still able to hold a conversation. Examples of moderate exercise are walking at a fast pace, dancing, and swimming.
When you're sweaty and so out of breath it's difficult to talk. Examples of vigorous exercise are running, fast cycling, and playing sports (football, GAA).
It's all about the oxygen, making your heart beat faster, your breathing get harder and your blood vessels dilate (hello unsightly redness) in order to bring enough oxygen to your working muscles. Examples of aerobic exercise are running and fast cycling.
This is the one that builds up your muscles and keeps your bones strong. Strength exercise usually makes people think of weight-lifting, but you can build muscle through many low-impact activities, as long as you do them for relatively long periods of time. Examples of strength building exercise are yoga, Tai chi, pilates, push-ups and squats.
The first connection between heart health and exercise
One of the first studies to show a correlation between physical activity and health was Dr Jeremiah Morris’s study on London transport workers. The study compared the rates of heart attacks for drivers as opposed to conductors of buses, trams and trolleybuses: although both jobs were similar, drivers spent the majority of their shift sitting down, while conductors constantly went up and down the stairs to sell tickets. Supporting the beneficial effects of all this exercise, conductors followed throughout the study had less than half the heart attacks of their sitting-down colleagues.
Moreover, when conductors got heart attacks, they were less severe and occurred later in life compared to those of drivers. This was not a result of their leaner physique: a follow-up study analysed the trouser sizes provided by Transport for London to all their uniformed workers to show that conductors had less heart attacks irrespective of their waist size.
Another study by Dr Morris confirmed these results by showing that postal workers that walked or cycled to deliver letters had far less heart attacks than those working at the post office. The link between physical activity and cardiovascular health was established.
Dr Morris died in 2009 at the age of 99½ (he insisted on adding the ½). Throughout his life and well into his 90s he followed a strict regime of swimming, cycling and walking.
Sign up for one of The Irish Times' Get Running programmes (it is free!).
First, pick the eight-week programme that suits you.
- Beginner Course: A course to take you from inactivity to running for 30 minutes.
- Stay On Track: For those who can squeeze in a run a few times a week.
- 10km Course: Designed for those who want to move up to the 10km mark.
Best of luck!