Vaccines and nutrition strengthen your immunity to viruses and other harmful pathogens—exercise may give it an even bigger boost. In this Q&A, Christine Schindler, MD, Assistant Professor of Medicine (General Internal Medicine), Icahn School of Medicine at Mount Sinai, explains why exercise likely helps strengthen the immune system and how much you need to reap the benefits.
How does exercise strengthen my immune system?
Exercise causes useful inflammatory responses in the immune system. With moderate exercise, these inflammatory effects can strengthen the immune system. Short bursts of high-intensity exercise are also quite beneficial to your health. One note of caution: According to research, more than 90 minutes of high intensity exercise in a single session is probably bad for your immune system. However, few people exercise at high intensity for that long.
What qualifies as moderate versus high intensity exercise?
A power walk or slow bike ride qualify as moderate intensity. You’re a little out of breath, but not too winded; you can speak in full sentences but not sing. High intensity exercise includes more vigorous activities like running, jumping rope, and tennis—you are getting your heart rate up, working up a real sweat, and are too out of breath to have a conversation.
Can exercise boost vaccine efficiency and reduce the risk of severe illness, especially in older adults?
The most recent studies suggest that exercise does boost vaccine efficacy for people of all ages. One study looked at people who got the flu and COVID-19 vaccines, then performed light to moderate intensity exercise for 90 minutes. About a month later, there was still a higher antibody response to those vaccines. In other studies, the immune response to the flu vaccine was found to be more robust in people who exercised regularly. In older adults, studies suggest that exercise leads to a longer antibody response that may offer more protection throughout the flu season.
These results are promising but not the last word, since researchers are also studying the effects of metrics such as age, gender, and the effect of daily exercise routines. However, the most probable answer is that moderate intensity exercise is beneficial for vaccine response. Exercising the day you get the vaccine also likely has some benefit.
How much, and how often, do I need to exercise to strengthen my immune system?
There is no specific number. Generally, the recommendation for all adults is to get 150 minutes of moderate intensity exercise a week, or 30 minutes a day, five days a week. Or get around 75 minutes of vigorous activity, or 15 minutes a day, five days a week. Strength training at least twice per week is also beneficial. There is evidence that walking 6,000 to 8,000 steps per day has positive health effects. In terms of benefits for your immune system, a power walk is going to be more effective.
What types of exercises do you recommend, especially for someone older or with mobility issues?
It’s important for older adults to walk if they can. Walking amongst nature decreases stress hormone levels and blood pressure and is beneficial for mental health. Joining a walking or exercise group can be very motivating. Senior centers and places like the YMCA often have exercise classes for older adults. It’s beneficial to work out in groups, whether walking around with friends, or going to a class. The team mentality helps people stay motivated. Regardless of your age, if you are new to exercise, it’s best to start slowly.
If you struggle with mobility, there are good beginner YouTube videos that show different ways to exercise: exercises you can do from the chair and exercises you can do in a small apartment space or without exercise equipment, such as using cans of beans instead of weights.
How can I get more exercise without joining a gym?
There are easy ways to incorporate exercise into your daily routine without a gym membership. For example, if you are a commuter, you can walk for part of your commute instead of taking the bus, and you can take the stairs at work instead of the elevator. If you don’t live in a neighborhood where you feel safe or the weather is bad, try walking up and down the stairs of your building or walk in a mall. Get creative with strategies that work for you and your schedule.