Physical activity and exercise are integral part of our lives. Closed gyms and lockdowns have taken its toll on our exercise schedules. Even for those who have never exercised, it has restricted their movement, leading to decreased energy expenditure. Even as lockdown restrictions are relaxed, there is limitation of movement and fear of exposure to the coronavirus.

Coupled with the fact that stress levels are higher than before, nutrition may not be optimal, sleep may be disturbed – exercising regularly is what we can easily manage.

The benefits from exercise are

• Enhancement of Immune system (our defence)
• Decreased risk of viral infections
• Decrease in anxiety and depression
• Weight maintenance
• Prevention and management of chronic diseases like heart disease, diabetes, hypertension, Obesity

The link between exercise and immune system

The immune system is highly responsive to physical activity. Our immune system is a distributed throughout the body across multiple organ systems. This is the system which defends against all types of infections and even some cancers. A robust immune system is our first line of protection against viral infections. Currently we do not have treatments for most viral infections including COVID 19 and our best defence is to strengthen our immune system.

A single bout of moderate intensity exercise leads to mobilization of T cells, B cells, Natural killer cells, neutrophils, and macrophages. These are the cells which are part of innate immunity and their numbers and function both improve with exercise. Some of these cells are released in circulation, and they look out for infected and inflamed cells, ready to deal with them. The immune system is highly responsive to physical activity, with the extent of the response increasing with both the duration and intensity of exercise.

The immune system weakens with age. The effect is on T cells and B cells, both of which are important part of the immune response. Human studies suggest that immune function is superior in highly active versus sedentary people, especially in the elderly, making regular exercise vital for them. Mental stress, undernourishment, quick weight loss, and improper hygiene have each been associated with impaired immunity.

What is the dose of exercise?

In the era of Exercise prescriptions, the type, intensity, and duration of exercise should be specific. Threshold is, at 60% heart rate reserve, not more than 60 minutes.

Practically it translates into moderate activity, 40-60 minutes at your heart rate reserve (HRR). Research on athletes or after intense bouts of exercise has shown a negative effect on the immune response. While there is 40%-50% decrease in the risk of upper respiratory infections after moderate exercise, the risk increases 200-600% after intense and prolonged exercise. 2%-18% of elite athletes experience illness episodes after competitive events, and 50 % of these are respiratory illness. Studies have also shown that regular physical may decrease incidence and mortality from Influenza and pneumonia.

Exercise also benefits by improving the gut microbiome, which is a vital part of our immune system.

Exercise and the elderly

Individuals above the age of 60 have higher complication and mortality rate. These are people who have been advised to avoid stepping out of their homes.

Physical activity and exercise have shown to be an effective therapy for most of the chronic diseases with direct effects on both mental and physical health. They have become especially essential for older people during the quarantine.

How to begin an exercise program?

If you have never exercised, start slow, with 20 minutes daily. Too much too soon will be counterproductive. Give your heart and muscles time to adapt and strengthen.

If you have any medical issues like heart disease, diabetes or high blood pressure consult with your doctor first. This is also important for people above the age of 45 years, even if there is no disease. A simple way to gauge exercise intensity is to be able to speak while exercising, though you cannot sing. If you have any breathing difficulty or muscle pain stop and take medical advice.

How to calculate HRR

• Subtract your age from 220 to get your maximum heart rate.
• Calculate your resting heart rate by counting how many times your heart beats per minute when you are at rest, such as first thing in the morning. Usually it is between 60 and 100 beats per minute for the average adult.
• Calculate your heart rate reserve (HRR) by subtracting your resting heart rate from your maximum heart rate.
• Multiply your HRR by 0.6 (60%). Add your resting heart rate to this number.
• Your heart rate should be around this number during exercise.

Activity trackers make it easier to track heart rate. You can also take your pulse for 15 seconds and multiply it by four.

Which are the right Exercises?

Walking (brisk walk) is a good beginning. If you want to walk at home, there are many Youtube videos available. Start small and aim big. Make increments of 10% every week, either in intensity or timing. Take online classes if you need guidance.

To strengthen your muscles, add weight bearing exercises like squats, push ups and planks thrice a week. Begin with 2-3 and aim for eight repetitions. Or pick up a water bottle or a can and you are ready to do weight training.

Yoga is a slow form of exercise, which focuses on flexibility and balance. It is a gentler way to begin exercise which helps in calming the mind too.

Last but not the least is Breathing exercises. A regular breath uses a small percentage of lung capacity. Strengthening the lungs can be achieved by doing deep breathing in different ways. Pranayam incorporates various types like abdominal breathing, lung breathing and alternate nostril breathing, to name a few. Doing these regularly benefits the lungs, heart and helps to manage stress too!

Suggestions for the elderly

• Walk around the house at regular intervals.
• Carry a bag of groceries (according to comfort) around the house.
• Walk in a straight line.
• Walk on heels/toes.
• Go up and down 3-4 stairs many times.
• Hold a chair and do squats.

References

The compelling link between physical activity and the body’s defence system https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6523821/

Physical exercise as therapy to fight against the mental and physical consequences of COVID-19 quarantine: Special focus in older people https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7118448/

Influenza and obesity: its odd relationship and the lessons for COVID-19 pandemic https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7130453/