Whilst most of us are sedentary, some of us enjoy exercising, usually to stay fit or lean. But there is a lot more to exercise than just fitness and weight management.
Regular physical activity can indeed improve our body composition and make us look good on the beach – there is nothing wrong with that. But it also shows great benefits in relation to mood, sleep, anxiety, stress, energy, libido, immune function, brain processing, cognitive abilities, cardio-vascular functions, lung capacity, bones strength, joints and connective tissues, among others. In other words, it promotes optimal health, make us more resilient, smarter and can even increase our lifespan! No magic pill could do that.
For our ancestors, physical activity was not optional. It was a requirement to find food and survive and we have genetically evolved to optimise our health by being physically active. But today, we have the choice to remain sedentary.
Physical inactivity has become the 4th leading cause of mortality with 3.2 million deaths worldwide every year (!!) and the primary cause of most chronic diseases. Addressing poor nutrition and lack of exercise could decrease the risk for all diseases by up to 70% in the US. It is time to get moving...
Exercise slows down aging
Exercise can slow down aging in a number of different ways.
Muscle mass is one of the best predictors of life expectancy. The more muscle we have, the better we age. By increasing our strength, mobility, functionality and balance, we can minimise the risk of falls and improve the chance of surviving them without a fracture. We can also maintain our functional capabilities and mitigate age-related pain. Exercises that engage the whole body and replicate real world movements are the most efficient, like climbing stairs, doing dead-lifts (picking-up heavy things) or farmer carries (carrying heavy things). Lifting weights also helps preserve bone density.
Exercise challenges and strengthens our organs to better withstand aging, accident and illness. If we exercise our body or our brain, we can maintain and develop our capabilities. Our efforts to build muscle mass help preserve our organ reserve and improve the function of vital organs such as the heart, lungs, kidneys and liver. But if we don't exercise, our organ reserve diminishes as we age and our organs become less functional. In other words, "use it or lose it".
Maintaining good cardio-vascular health is important to prevent heart failure. Even just walking or climbing stairs can help us do that. Aerobic exercise increases our capillary network (the blood vessels supplying nutrients and oxygen to the muscles), raises the stroke volume of our heart and improves oxygen utilisation by our lungs.
Aging is associated with systemic inflammation, which predispose us for chronic diseases, including cancers. But regular exercise and an active lifestyle reduce inflammation, lower all-cause mortality and enhance health and lifespan.
Advanced Glycation End-product ("AGE") formation in our body is another natural aging process that can contribute to the development of many degenerative diseases, such as diabetes, atherosclerosis, kidney disease and Alzheimer's. But once again, regular physical exercise can reduce AGE accumulation, which can lead to an increase in lifespan.
Many studies have observed the anti-aging effects of regular exercise and one study even showed that older individuals who have exercised regularly throughout their life have "defied the aging process", with the immunity, muscle mass, testosterone, body fat and cholesterol levels of a young person.
Exercise makes us smarter
So exercise can make us look and feel younger, that's great! But did you know that it can also make us smarter?
Physical activity increases the blood flow in the brain, stimulates brain functions, increases the brain volume and IQ. Woohoo!
It is also one of the most potent stimulants for the production of Brain-Derived Neurotrophic Factors ("BDNF") that helps brain cells grow new neurons and repair. New connections are formed in our brain, which improves our attention, memory and executive functions. This is why mild exercise is recommended after brain injuries to fasten recovery.
A study in Sweden showed that people who improved their fitness also improved their IQ (and more so with cardio than with resistance training), reached higher education levels, higher socio-economic standing and generally more satisfaction in life.
Exercise boosts our energy
Regular exercise increases the number and the size of mitochondria (the power plants in our cells responsible for the production of energy), which makes us feel more energised. More mitochondria means more energy but also less reactive oxygen species (the free radicals that make us age quicker).
For instance, one study found that interval training resulted in a 49% increase in mitochondrial capacity in younger individuals and in a 69% increase in older ones. Another study observed that exercise can minimise and even reverse the natural decline in mitochondrial function.
Exercise makes us feel good
Regular exercise stimulates the release of endorphins (“endogenous morphine”), serotonin, endo-cannabinoids and oxytocin (the “love” hormone). It also increases the number of dopamine receptors in the brain and the time dopamine remains in the synapses. It reduces stress (by promoting GABA production) and tension, gives a sense of achievement and blunts the pain-response. It is as efficient as anxiolytic or antidepressant medication.
To feel these benefits, even mild physical activity such as walking works fine. Hippocrates once said "if you are in a bad mood, go for a walk. If you are still in a bad mood, go for another walk."
More than 264 million people worldwide have been diagnosed with depression and 284 million with anxiety, which put them at greater risk of developing cardiovascular diseases, Alzheimer's, diabetes and of dying prematurely. A moderate exercise regime could greatly improve these sad statistics.
Other studies have showed that exercise reduces behavioural and disciplinary issues with kids, whilst also improving their attention and scores.
Exercise for weight loss?
Contrary to popular belief, exercise is not a very good solution for weight loss. It is not as effective as a healthy nutrition for weight management. As the saying goes, we can't outrun a bad diet. Chronic exercise increases our appetite, slows down our metabolic rate and promotes fat storage, due to hormonal responses associated with stress and survival.
But once we have adopted a healthy nutrition, then exercise can help us burn fat and get leaner faster. Note that leaner doesn't mean lighter, as muscle is much more dense than fat and takes up much less room than an equivalent weight of fat.
When we exercise, we can either use glucose or fat to produce energy, depending on our nutrition, the exercise intensity (heart rate) and how much glycogen is stored in our muscles. Exercise depletes some of the muscle glycogen stores, which can allow the body to shift from using glucose to using fat for energy. This is why exercising fasted first thing in the morning can be a good strategy to burn more fat.
Aerobic exercise (at lower heart rates, when enough oxygen is available to burn fat) paired with a low carbohydrate nutrition optimises fat metabolism. A simple formula to stay below the aerobic maximum is to keep our heart rate below 180 minus our age.
On the other hand, exercising above the aerobic maximum, even for brief periods, can compromise the fat burning state. The body starts burning glucose for energy and it becomes difficult to return to a fat-burning state, even when returning to the aerobic range.
Other health benefits
Regular exercise have many other health benefits. It activates the lymphatic system that is required to support our immune function, control excess swelling, clean metabolic waste products, take care of fat disposal and deliver nutrients to the body. It stimulates gut flow and gastric motility and promotes the development of good bacteria. It improves sleep and helps women make the transition to menopause much more manageable.
How much exercise should you do?
The right amount of exercise for you depends on your current level of activity, your stress levels and whether you are dealing with any health issues.
If you are sedentary, any physical activity would help. You can start by walking every day. If you are older, it is even more important to practice regular physical activities that preserve strength, functionality, flexibility and balance, such as yoga, Tai-Chi or gardening.
If you can do more, a good starting point would be to do strength training for at least 30 minutes 3 to 4 times a week, as well as regular movements throughout the day (walking, taking the stairs, squatting or stretching…), and some kind of physical activity at the week-end (playing with the kids, walking, cycling…). If you can add one high intensity activity once a week, for 15 to 20 minutes at a much higher heart rate, that is even better.
A study showed that higher levels of moderate-to-vigorous exercise of about 1 hour every day (way above the minimum international recommendations of 150 minutes per week) are associated with longer life expectancy. So if you lack motivation, find a buddy or join a class, find a sport or a physical activity that you like, use the stairs when you can, arrange for walking meetings or conference calls outside.
On the other hand, too much exercise is unhealthy. Many people spend hours walking or jogging on a treadmill without any benefits. Overtraining does not work to optimise body composition and to maintain healthy cortisol (stress) levels. It promotes systemic inflammation of muscles, joints and other systems (cardiovascular, immune and endocrine systems), whilst insufficient recovery time can result in injury, illness and burnout. Chronic exercise above the maximum aerobic heart rate requires glucose for fuel, which leads to sugar cravings, hunger, spikes in insulin production and fat storage or break down of lean muscle tissue in case of calorie deficit. This is why chronic exercisers struggle to reduce their body fat or increase their muscle mass, despite arduous training regimens.
Start exercising today!
Find a physical activity that you truly enjoy and practice it regularly to keep in shape, reduce your stress, improve your mood and sleep, feel better and more energised. Even mild exercise can slow down aging so that you can enjoy a longer, healthier, more active and pain-free life. Add regular exercise to your life to look and feel younger!
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