Is it ever too late to start exercising?

We all know that exercising regularly is good for us. As well as helping to control weight and build muscle, exercise can keep us healthy on the inside too. Exercising reduces the risk of heart disease and can help control blood sugar. It also strengthens our bones and muscles, and even improves our mental health. But if you’ve led a sedentary life, could exercising have negative effects on your health? We look at what the science says and answer the question if it’s ever too late to start exercising.

Is being sedentary the new smoking?

Fifty years ago, the majority of people smoked cigarettes. They didn’t understand the long-term health impact of their habit. Today, huge numbers of people work at computers and barely stand for hours each day. According to the Surgeon General, over 60% of Americans aren’t active enough, and a quarter are almost completely sedentary.

Sitting for more than eight hours each day increases the risk of chronic diseases and premature death by 10-20%. That’s according to a study published in the American Journal of Public Health. That’s bad, but not as bad as smoking, which increases the risk of premature death by around 180%. So sitting for too long isn’t the new smoking, but it’s certainly not good for us.

People who work desk jobs that require little to no physical effort are particularly at risk. According to the U.S. Bureau of Labor Statistics, about 38% of all jobs require light work or less. That rises to 40% of legal jobs and 31% of office jobs. Being sedentary is a risk in almost all occupations. Only people in the construction and maintenance industries get enough exercise from work.

What does lack of exercise do to the body?

The biggest danger of leading a sedentary life is heart disease. This is true even for people who don’t have other risk factors, such as ​​obesity, high blood pressure, or high cholesterol. You can be thin and otherwise healthy and still be at risk.

In fact, lack of physical activity increases your chances of developing these risk factors too. That’s because exercise helps to raise good cholesterol and lower bad cholesterol. Exercise also helps to regulate blood sugar, so sedentary people are more at risk of developing type 2 diabetes.

Finally, exercise helps to regulate other bodily processes, such as sleep and mental ability. This reduces the risk of developing dementia in old age. Getting enough exercise is important not only to extend life, but to improve the quality of life as well.

How exercise is measured

Although many Americans lead sedentary lives, you may be getting more exercise than you realize. You don’t have to go to the gym to get fit. The Mayo Clinic suggests the average adult should get at least 30 minutes of moderate physical activity each day. 

Exercise impact is measured in METs, or Metabolic Equivalents. One MET is the amount of energy it takes to sit still. Just keeping you alive requires about one calorie per hour for each 2.2 pounds of body weight. So a person who weighs 150lb burns through about 68 calories per hour. A person who weighs 250lb needs 114 calories per hour. And a person who weighs 100lb needs 45 calories per hour.

“Moderate” activity means anything that costs 3-6 METs. That’s burning 3-6 times more calories than you need just to sit still during the same amount of time. Vigorous exercise burns more than 6 METs. Light exercise burns less than 3 METs.

Your fitness level affects the amount of METs required to complete an activity. Muscles require more calories to maintain than fat, so a person with a muscular frame will need more calories to sustain their build. That means they need to work harder to reach moderate or vigorous activity levels. For sedentary people, walking at a brisk pace (about 4mph) is enough to reach the moderate threshold. A professional athlete might have to start running before they hit 3 METs.

Unlikely forms of exercise

So what kind of activity counts as moderate exercise? Walking, cycling, and playing sports such as badminton or doubles tennis are enough for most people. But don’t despair if the weather is bad or you don’t have a gym membership. Mowing a lawn, vacuuming, or washing windows all count as moderate exercise too.

Many everyday activity can provide the same benefits as working up a sweat at the gym. Housework, walking around a store or mall, and gardening are good ways of working out without realizing. Sex is also great exercise! That’s because exercise isn’t about the specific activity you do, but what that activity does to your body.

A quick way to measure the effectiveness of an activity is to pay attention to your breathing. You shouldn’t be gasping for breath, but if speaking in full sentences is difficult then you’re in the right zone. Instead of ambling slowly through grocery store aisles, pick up the pace a little until you’re breathing harder. Or park at the far side of the lot and walk faster to your car and back.

Another way to check your activity level is by monitoring your heart rate. Exercise becomes most effective when our hearts are beating at 70% of their maximum rate or above.

A good estimate for your maximum heart rate is to subtract your age from 220. So for a 20-year-old, their maximum heart rate is 200 beats per minute (bpm). For a 50-year-old, it’s 170bpm. To find 70% of the maximum, multiply by 0.7. For a 20-year-old, that’s 140bpm (200 x 0.7). For a 50-year-old, it’s 119bpm.

If you have a smartwatch or heart rate monitor, try to get your heartbeat above this level during exercise to get the most benefit.

Can too much exercise be bad?

Overdoing it while exercising is possible, and it can cause both short and long-term injuries. The most common injuries are sprains and pulled muscles, but extreme training can damage your heart. There is a link between high intensity activity and the risk of heart attacks. This mostly affects people with underlying heart disorders.

Exercise makes our hearts work harder. That’s good, but only to a point. Too much high-intensity exercise increases the risk of physical changes. These include thickening of the heart walls and scarring. That increases the risk of sudden death. Some studies have shown that extreme athletes show biomarkers of heart damage after competing. These usually heal after a few days, but repeatedly putting that much stress on your heart can cause long-term damage that can’t be healed.

Because of this extra stress, it’s safer to stick to moderate exercise. Alternatively, limit the amount of vigorous exercise you do. The Department of Health and Human Services recommends 150 minutes of moderate exercise per week. That’s 30 minutes per day for five days. If you prefer vigorous exercise activities, limit them to 75 minutes per week.

If you’re exercising to lose weight, you should stick to no more than 300 minutes of moderate exercise. That’s equal to 150 minutes of vigorous activity. You can also mix equivalent amounts of moderate and vigorous exercise. For example walking the dog each day and attending one spin class per week.

Can starting exercising late in life be bad for you?

We all need to exercise, no matter what age we are. But older adults need to pay attention to their relative fitness and avoid making chronic conditions worse. HHS recommends older adults do the same amount of exercise each week as young adults. However, they should focus on balance training and muscle strengthening activities.

Taking heart rate and METs into account is a good way to exercise within your limits and avoid overdoing it, no matter what age you are. There are formulas to help work out the impact of exercise based on your body. Staying within your optimal heart rate range and reducing the frequency of vigorous exercise as you get older can keep you fit without creating additional risk.