The world is constantly on the lookout for new ways to look and feel younger, and possibly live longer. While we have had little success in finding sustainable and healthy antidotes to the natural effects of ageing, exercise is something that has always done its bit. Yoga practitioners and fitness experts tend to prescribe a host of exercises that could delay ageing and help you stay young, and more importantly, healthy.
While exercise may not delay or slow down ageing per se, what it can do is “hold off some of the bad outcomes of ageing,” underlines Michael Rae, science writer at strategies for engineered negligible senescence (SENS) Research Foundation, California, and co-author of Ending Aging, with biomedical gerontologist Aubrey de Grey.
“Physically active individuals tend to have lower incidences of various chronic diseases including hypertension, diabetes, osteoporosis and even cancer. An epidemiological study demonstrated that the risk of all-cause mortality (death) was higher in physically inactive people,” points out Dr Amit Sharma, group lead, Senescence Immunology Research, SENS Research Foundation, California. “Exercising can affect several underlying mechanisms of ageing,” he adds.
Role of exercise in healthy ageing
Rae and Dr Sharma explain the following ways how exercise eases off the effects of ageing, narrating the science behind them:
1. Reduces risk of falls, fracture and osteoarthritis: “Strengthening the bones, muscles and cartilage (with exercise) reduces the risk of fracture, osteoarthritis and catastrophic falls,” says Rae.
2. Improves metabolism of blood sugar and fats: “Strength training (like lifting weights) can improve how cells use glucose or sense nutrition,” explains Dr Sharma. “It also improves the activity of important cellular enzymes like mTOR, FOXO and sirtuins.” Apart from playing a role in energy balance and metabolism, these enzymes together have potential functional implications on longevity and ageing‐related diseases.
3. Improves cholesterol profile and lowers blood pressure: “Exercise tends to improve the cholesterol profile and lower blood pressure, which slows the progression of cardiovascular diseases,” says Rae.
4. Protects against brain damage: “Anything you do to maintain the cardiovascular health, also protects the brain from damage (from small, transient strokes to the larger and more catastrophic ones),” says Rae. Exercises that improve cardiovascular fitness are called cardio, endurance or aerobic exercises, and include brisk walking, running, stair climbing, swimming, hiking, high-intensity interval training (HIIT), etc.
5. Stimulates brain function: “Exercise stimulates the release of a variety of messenger-molecules that support brain function, such as brain-derived neurotrophic factor (BDNF),” says Rae.
6. Improves immune system functioning: The function of the immune system is known to decline with age. “Exercise appears to improve the function of the immune system, holding off infections and cancer (and also increases the chances of survival from cancer),” remarks Rae.
Dr Sharma explains that “Exercise improves and maintains the functioning of our immune cells, especially the Natural killer (NK) cells (that can kill precancer and cancer cells).”
7. Lowers inflammation: Inflammation is the body’s natural immune response to foreign pathogens and germs. However, dysregulation of the immune system due to ageing can result in chronic inflammation, which is damaging.
“Exercise can reduce inflammation and the mechanisms involved in producing inflammation,” says Dr Sharma.
The NK cells, a part of our innate immune system, are not only responsible for removing damaged old cells, but senescent cells as well. Dr Sharma says, “exercise has been shown to improve immune-mediated removal of these old cells which not only inhibit various tissues from functioning properly, but can also cause build-up of inflammation.”
8. Improves lysosomal function and autophagy (the natural self-cleansing routine of cells): “As our cells age, there is a build-up of old, non-functional proteins and other cellular components. These are removed and recycled in an organelle called lysosome by a process called autophagy,” explains Dr Sharma. “Aerobic exercises have been shown to improve lysosomal function.”
9. Improves the function of mitochondria (the powerhouse of the cell): Mitochondria are important cell organelles that start breaking down as we age.
“Aerobic exercise can improve mitochondrial function and repair, so that the energy generation process is maintained, and less reactive oxygen species (ROS) are produced,” says Dr Sharma.
While moderate amounts of ROS are essential for the maintenance of several biological processes (including gene expression), high concentrations of ROS can cause oxidative stress, which results in severe damage to cell organelle membranes, DNA and proteins, causing several age-related conditions like cardiovascular diseases, chronic obstructive pulmonary disease, chronic kidney disease, neurodegenerative diseases, cancer, sarcopenia and frailty.
10. Improves the function of DNA repair enzymes: “Exercise improves the function of DNA repair enzymes that tend to decline in expression or function with age,” says Dr Sharma. According to a 2015 research, exercise appears to, in some way, contradict age-related DNA damage. The decrease in oxidative damage associated with exercise training could be explained by an increase in antioxidant and metabolic efficiency, which possibly prevents the stimulation of DNA repair enzymes. Accumulation of damaged DNA finds relevance in ageing and some age-related diseases, ranging from cardiovascular diseases and diabetes mellitus, to cataracts and even several forms of cancer.
11. Slows down the loss of telomeres (the ends of our chromosomes): Telomeric repeat sequences at the end of our chromosomes become shorter every time a cell divides, eventually resulting in cell death. “Exercise can slow down this process,” says Dr Sharma.
12. Slows down the occurrence of detrimental epigenetic changes: “Exercise slows down age-related epigenetic changes that cause cell damage,” says Dr Sharma. “Epigenetic changes are modifications on chromosomes that can change the ability of genes to function normally. Several studies have shown how these chemical changes can accumulate with age, and regular exercise can really slow down these changes,” he adds.
- Exercise improves one’s cell maintenance, metabolism and multiplication, wards off age-related chronic illnesses and keeps bodily systems (such as the immune system) and brain in their pink, ultimately enhancing one’s overall health, well-being and longevity.
- It is recommended to engage in moderate aerobic exercise for at least 30 minutes (five days per week) or vigorous aerobic exercise for at least 20 minutes (three days per week), apart from strength training (minimum two days per week) coupled with regular balance and flexibility workouts.