Keep Moving. Facts on Fitness, Part 1
It's Sunday morning and after my morning cup of tea, I’m off for a run with the dog. I just asked my husband if he fancies coming along. His response was less than enthusiastic. He’s not a huge fan of conventional exercise. He’s not alone.
A survey of >92,000 people in England found that participation in, and the desire to participate in, physical exercise declines progressively throughout adult life (1). Why is that? Being too busy with growing families and careers for it to feature very high up on the to-do list is undoubtedly a factor. The demands on our time can leave little space for exercise and let’s face it, it’s often a bit hard. Instead of being an enjoyable habit, for many it becomes something we dabble in on occasions because, “it’s good for us”. But the lack of practice often leads to sore muscles and joints and sometimes more serious, longer-term injury. It’s hard to form a habit when it hurts, and so we come to the conclusion that exercise isn’t for us and we’re getting too old.
Unfortunately, if we think like this in our 40s and 50s we run the risk of becoming the most sedentary age group of adults aged 65 and older, who spend 10 hours of more sitting or lying down each day (2). Lack of exercise is the major cause of disease and poor mental and physical fitness in older age. In contrast, one longitudinal study found that highly active people aged 50 years and older in England had half the risk of death compared with those that were sedentary (3).
This is a three part blog. In this part, we look at what the science has to say on how exercise impacts heart health, blood pressure, diabetes and cancer. Part 2 examines the effects of physical activity on strength, metabolism, bone density and arthritis, and part 3 looks at memory and mood.
A powerful example of how exercise benefits heart health came to light in the 1950s when researchers found that middle aged double decker bus conductors were half as likely to have heart attacks as their bus driver colleagues. The difference was that the conductors were climbing about 600 stairs each working day whereas the drivers were sitting for 90% of their shifts (4)(5).
A more recent study published in the journal Circulation, carried out a two year exercise intervention study on people aged 45-64 who were healthy but mostly sedentary. Participants were randomly assigned to either a program of non-aerobic exercise three times a week or one of moderate- to high-intensity aerobic exercise four or more days a week. After two years, the group doing the higher-intensity exercise saw dramatic improvements in their heart health, including improvements in oxygen uptake and decreased cardiac stiffness, potentially protecting against future heart failure (6).
It isn’t just aerobic exercise that improves heart health either. A study published last year that included 12,591 men and women with a mean age of 46.5 years, found that even one resistance (strength) exercise training session a week was associated with a 75% reduced risk of cardiovascular disease (7).
Persistent high blood pressure increases the risk of heart attack and stroke. A meta-analysis of 93 trials, involving 5223 participants found that various different types of exercise program (endurance, resistance and combined training) were effective at reducing blood pressure, particularly if the program lasted longer than 24 weeks (8). A 2019 research paper looked at 391 previously published studies and found that exercise produced similar results in lowering blood pressure to medication in people with high blood pressure (9).
Exercise also reduces type 2 diabetes risk. A 2014 study of nearly 100,000 middle aged and older women followed for 8 years, found that those who did at least 150 minutes a week of aerobic moderate and vigorous physical activity and at least 60 minutes a week of muscle-strengthening activities had significantly lower risks of type 2 diabetes compared to inactive women (10).
Around 1,000 people every day in the UK are diagnosed with cancer (data from 2015-2017). That’s one every two minutes. Since the early 1990s, the incidence rates for all cancers combined have increased by 12% in the UK. To add in one last unhappy statistic, the UK incidence is ranked higher than 90% of the world (11). Why is this? Western lifestyles that impact on how much we move, what we eat, how well we sleep and our stress levels, play their part. Therefore, the good news is that the situation is not a foregone conclusion; these factors are modifiable. Looking at activity levels, a 2016 study which included 1.44 million participants with a median age of 59 years, found that high levels of leisure-time physical activity were associated with lower risks of 13 cancers including oesophageal adenocarcinoma, liver, lung, kidney, gastric cardia, endometrial, myeloid leukaemia, myeloma, colon, head and neck, rectal, bladder and breast (12).
If you’re reading this and thinking you’d better start exercising, don’t panic! You don't have to run a marathon. Make it easy. Make sure it’s enjoyable. Running it (excuse the pun) past your GP may be wise if you haven't been doing any fitness for a while or if you have existing medical conditions. There are many ways to exercise. My husband loves to see the fruits of his labours. This lockdown has seen him digging soil and shovelling sand and cement to create a new patio. The exercise is incidental and places resistance on the muscles, as well as being aerobic. However, we only need one patio, so he’ll soon need a new project, as consistency is key!