Exercise in Old Age Strengthens Your Immunity and Heart

Story at-a-glance -

  • Older, very active cyclists have been shown to have stronger immune systems than their nonexercising peers, as evidenced by higher T-cell activity; in fact, their immune function was comparable to young adults in their 20s
  • A pattern of lifelong exercise is believed to contribute to your ability to retain healthy levels of muscle mass, muscle strength, body fat and cholesterol as you age
  • In a separate study, moderate- to high-intensity aerobic exercise at least four days a week increased the heart health and circulatory function of middle-aged adults, as compared to more moderate exercise performed just three days a week
  • Because sitting is a health hazard and the average adult sits nine to 10 hours a day, make a plan to incorporate more exercise and movement into your day
  • If your job requires a lot of sitting you may want to set reminders to get up and move, suggest standing meetings and take periodic stretch breaks

By Dr. Mercola

New research once again underscores the value of and need your body has for regular exercise. In one study,1 older adults who exercised regularly were shown to have stronger immune systems, as evidenced by higher T-cell activity, than their nonexercising peers. While you might expect such a result, researchers found the immune function of this particular group of very active adult cyclists, ages 55 to 79, to be comparable to young adults in their 20s!

Related research indicates a pattern of lifelong exercise also enables you to retain healthy levels of muscle mass, muscle strength, body fat and cholesterol as you age. In a separate study,2 moderate- to high-intensity aerobic exercise at least four days a week was shown to boost the heart health and circulatory function of middle-aged adults, as compared to more moderate exercise three days a week.

If you have been putting off exercise, now is the time to reprioritize it, especially if you're over 45. One researcher called these middle years the "sweet spot" for your heart and blood vessels because they still have some plasticity, and exercise promotes elasticity and oxygen flow. Whatever you do, reduce the amount of time you spend sitting and look for ways to get more exercise and movement into your daily routine. You're certain to feel better and your immune system and heart will thank you.

Fit Older Adults Have Stronger Immune Systems

New research published in the journal Aging Cell3 highlights the importance of exercise for older adults, noting the positive effect it can have on your immune system. Previous studies have validated the health benefits of exercise, at all ages, to prevent conditions such as back pain, bone loss, physical disability and cognitive decline.

In the current body of work,4 researchers in the U.K. analyzed the blood of 125 very active adult cyclists, ages 55 to 79, for markers of T-cells. T-cells, which help your immune system fight infections, are produced in your thymus, a gland that gradually shrinks as you age.

Notably, T-cell activity was not only higher in active versus inactive older adults, but the very active cyclists were also producing a level of T-cells common among young adults in their 20s. According to Science Daily, these findings are significant to adults in the U.K., in part, because:5

  • Less than half of adults over age 65 get enough exercise to stay healthy
  • More than half of adults aged 65 or older suffer from at least two chronic diseases 

"[The study] really tells us that staying physically active all of your adult life can prevent much of what we think of as aging, including immune aging," said study author and professor Janet Lord, director of the Institute of Inflammation and Aging at the U.K.'s University of Birmingham.6 She added:7

 "The immune system declines by about 2 to 3 percent a year from our 20s, which is why older people are more susceptible to infections, conditions like rheumatoid arthritis and, potentially, cancer. Because the cyclists have the immune system of a 20-year-old rather than a 70- or 80-year-old, it means they have added protection against all these issues."

Professor Emeritus Norman Lazarus, 82, of the Center of Human and Aerospace Physiological Sciences at King's College London, who was a study participant and coauthor of the research, said, "If exercise was a pill, everyone would be taking it." Professor of human and applied physiology and Center director Steve Harridge stated, "Being sedentary goes against evolution because humans are designed to be physically active."8

Older Adults Who Exercise Regularly Do Not Lose Muscle Mass or Strength

According to Science Daily,9 the research drew from a particular subset of fit older adults. To join the study, the 125 participants had to meet the following criteria:

  • Men had to be able to cycle 100 kilometers (km), roughly 62 miles, in under 6.5 hours
  • Women had to be able to cycle 60 km, about 37 miles, in 5.5 hours
  • Excluded from consideration were smokers and heavy drinkers, as well as those suffering from high blood pressure or other health conditions

Given those baselines, the exercising group was compared to a group of nonexercisers — 75 healthy older adults ages 57 to 80 and 55 healthy young adults ages 20 to 36. About the comparisons NBC News Health said, "Here's more evidence that regular exercise really is the best medicine: Avid cyclists as old as 79 had healthy muscle and immune function as good as people 30 years younger who did not exercise."10

In a related study,11 interestingly, the exercise group showed no loss of muscle mass or muscle strength. Beyond that, researchers noted participant body fat and cholesterol levels did not increase with age. Moreover, they observed testosterone levels among the men remained high, aiding the participants in avoiding most of the effects of "male menopause."

Brian Matkins, 82, a member of the internationally recognized cycling organization Audax that organizes long-distance bike rides all-around the U.K., said, "One of the first results I got from the medical study was I was told my body fat was comparable to that of a 19-year-old." Lord stated:12

"[I]mportantly, our findings debunk the assumption that aging automatically makes us frailer. Our research means we now have strong evidence that encouraging people to commit to regular exercise throughout their lives is a viable solution to the problem that we are living longer, but not healthier, [lives]."

Exercise at Middle Age May Revitalize Your Heart and Circulatory Function

Similar to your thymus gland, as mentioned, your heart also stiffens and shrinks as you age.13 It is also affected by the amount of exercise you get. A study published in the American Heart Association's journal Circulation,14 focusing on the exercise habits of older adults, indicates regular physical exercise can, in effect, revitalize your heart.

Ben Levine, professor of internal medicine at the University of Texas Southwestern Medical Center and director of the Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital, in Dallas, and his team recruited 53 adults for a two-year study. The participants, ages 45 to 64, were randomly assigned to one of two exercise groups.

Group 1 engaged in nonaerobic exercise that included basic yoga, balance training and weight training three times a week. Members of the second group were assigned a trainer and performed moderate- to high-intensity aerobic exercise at least four days a week. After two years, says Levine, the group involved in higher-intensity exercise saw dramatic improvements in their heart health. "We took these 50-year-old hearts and turned the clock back to 30- or 35-year-old hearts," he noted.15

The hearts of participants in the higher-intensity exercise group processed oxygen more efficiently and were notably less stiff. "And the reason they got so much stronger and fitter," Levine said, "was because their hearts could now fill a lot better and pump a lot more blood during exercise."16

This is significant because even healthy older adults, as they age, are subject to their hearts becoming smaller, less flexible and less efficient at processing oxygen. While these signs generally begin to appear in your 50s or early 60s, a lack of exercise may speed up the process.

Levine and his colleagues suggest if you are in midlife, now is the time to get in shape. While you may think it's too late — especially if you are 45 or older — the study reflects that even nonexercisers who get in shape at middle age may be able to avoid or reduce heart declines due to aging. "The sweet spot in life to get off the couch and start exercising … is in late middle age when the heart still has plasticity," Levine says.17

One aspect of the study that caught my attention was the use of high-intensity interval training, one of my favorite exercise regimens. I love it because it stresses my heart and forces it to function more efficiently. In Levine's study, the moderate- to high-intensity exercise group performed what is referred to as 4x4 intervals — four minutes of intense activity at 95 percent maximum ability, followed by three minutes of active recovery. The sequence is repeated four times and serves to strengthen both your heart and circulatory system.

A Sedentary Lifestyle Is Associated With Poor Health and Chronic Disease

Switching back to the study involving older cyclists, the fact active adults participating in the research were shown to be in better health than their nonexercising peers was not much of surprise. The benefits of exercise are both long-standing and well-known. The real news was with respect to how the group of active older adults compared to nonexercisers who were a fraction of their age.

According to NBC News Health,18 "[T]they also looked as healthy, biologically, as a group of people aged 20 to 36 who did not exercise … By some measures, their bodies had not aged at all." About the risks and consequences associated with inactivity, Harridge stated:19

"The findings emphasize the fact the cyclists do not exercise because they are healthy, but they are healthy because they have been exercising for such a large proportion of their lives. Their bodies have been allowed to age optimally, free from the problems usually caused by inactivity. Remove the activity and their health would likely deteriorate."

His point is well taken given the current statistics about the health and activity levels of older adults. For example, in the U.S.:20

  • Approximately 80 percent of older adults suffer from at least one chronic disease, while 77 percent are battling at least two21
  • Less than 5 percent of adults get 30 minutes of daily physical activity, and only 1 in 3 adults meets the exercise recommendations issued by the U.S. Centers for Disease Control and Prevention (CDC)22 for weekly physical activity
  • Just one-third of adults ages 65 to 74 are physically active
  • More than 80 percent of adults do not meet the recommended guidelines for both aerobic and muscle-strengthening activities

Keep in mind the exercise recommendations made by the CDC23 of at least 2.5 hours of moderate-intensity aerobic exercise each week, 75 minutes of vigorous-intensity activity or a combination of both, should be seen as a starting point. Every little bit of movement and exercise you can incorporate into your day beyond those markers will be beneficial. Research24 published in 2015 concluded the ideal exercise dose for health and longevity is actually 7.5 hours per week, or just over an hour a day. 

Those who met the guidelines of 150 minutes per week of moderate exercise lowered their risk of death by 31 percent during the 14-year study period, compared to those who did not exercise. Those who tripled the recommended amount of exercise and engaged in activities such as walking for 450 minutes per week lowered their risk of premature death by 39 percent, compared to nonexercisers. Bear in mind the amount of time you spend exercising will be greatly influenced by the types of exercise you choose.

The more intense the exercise, the less time you need to spend at it. In my opinion, the best way to achieve optimal health is to adopt a comprehensive fitness routine (along with proper diet and sleep). Some forms of exercise I recommend include: core training, high-intensity interval cardio, peak fitness, strength training, stretching and walking. With respect to walking, I suggest you set a goal for 15,000 steps a day and challenge your family members and friends to achieve the same.

Sitting All Day Is Bad for Your Health

Chances are you may be sitting down while reading this article. It's a common practice for many to sit in a chair all day for work, only to return home and spend even more hours sitting on a couch or chair. While it may sometimes be necessary and even comfortable, a growing body of research suggests this all-too-common practice is detrimental to both your physical and mental well-being.

In fact, according to the World Health Organization, sedentary behavior is the fourth leading cause of premature death worldwide.25 Prolonged sedentary time — generally defined as sitting for eight hours or more each day — has been associated with a number of health risks, independent of how much exercise you do.

As noted in the Annals of Internal Medicine,26 after evaluating 47 meta-analyses, researchers concluded, "Prolonged sedentary time was independently associated with deleterious health outcomes regardless of physical activity." By sitting too long, the study authors suggest you increase your risk of:

  • Death from any cause
  • Developing and dying from cancer
  • Developing and dying from cardiovascular disease
  • Suffering from Type 2 diabetes

The British Medical Journal says adults, on average, spend nine to 10 hours each day sitting.27 The damaging effects of this level of inactivity simply cannot be offset by a 30- or 60-minute workout a few days a week. The key is to get more nonexercise movement into your day. As featured in the video above, to help reduce sitting and encourage movement, I use a standing desk. I also do most of my reading on a Kindle when I go for my daily walks on the beach. Some other tips you might consider to help you reduce sitting include:

Interspersing active tasks with sitting tasks as much as possible throughout your day

Taking small breaks hourly and incorporating stretching and other exercise into those breaks

Inviting co-workers to take part in standing or walking-and-talking conversations and meetings (you can try this approach at home with your spouse and kids, too)

Tracking how long you spend sitting and setting goals to reduce your inactive hours

Setting goals to limit your sitting time and inviting others to join you in actively reducing the amount of time you spend sitting

Using reminders to trigger you to get up and move around after periods of sitting