We’ve all been told that adequate exercise and physical activity are a cornerstone of good health. Almost everyone knows this. But how strong is effect of physical activity on our healthy? Is it as simple as more exercise equals better health?
This section aims to answer these questions and briefly reviews the connection between exercise and immune function.
The Importance of Physical Activity for Immune Function
The results of various studies on the overall aspects of physical activity have shown a myriad of beneficial results. Especially, for those people that chose to make exercise an integral part of their daily lives.
Some highlights of this research include:
- Athletes appear to have improved natural killer cell activity [1, 2, 3]
- Older adults who exercise regularly demonstrate better immune function [4, 5, 6]
- Moderate regular physical activity can lower inflammation within the body [7, 8]
- Exercise can improve improve brain health [9, 10]
And this is just a small portion of the overall benefits that exercise can have on our health.
Different Levels of Physical Activity Can Have Different Outcomes
The relationship between physical activity and immune function isn’t as straightforward as we may think. Instead, research has shown that the impact on immunity depends on various factors.
Generally, the following relationships have been noted :
- Low to moderate intensity sessions of limited duration are beneficial
- Prolonged high intensity sessions of extended durations are unfavorable
Not all exercise is beneficial
Periods of intense training may suppress neutrophil (one of best weapons of innate immunity) activity [12, 13] and a variety of other important immune functions . And this can present an “open window” for infection.
But this is just the general theme and there are other factors which impact the relationship, including:
- Change in body temperature
- Change in blood flow
- Hydration status during exercise session
- Body position and type of muscle isolation
- Concentration of cytokines and hormones in the blood stream
Taken together, these factors will determine the impact that physical activity will have on our immune systems. Accordingly, it is important that we don’t simply focus on the quantity of the physical activity, but also the quality.
Physical Activity in the Modern World
In the end, it appears the benefits to be gained from regular physical activity far outweigh any potential issues (typically only seen in over training). Yet, unfortunately, only a small portion of people truly take advantage of the benefits of physical activity.
In the United States physical activity has progressively decreased in the past 50 years . This decrease is in part due to changes in occupational demands (more sedentary jobs), but also likely impacted by less physically demanding leisure time habits as well (TV vs outdoors).
This means that even though we all know that physical activity is a vital aspect of our health, it seems we take this knowledge for granted.
We need to find ways to make physical activity an integral part of our lifestyles and daily choices. We need to find ways integrate physical activity into our jobs and our homes. Each little step we take can produce an end result that will likely far outweigh any dedicated training regimens.
This section reviewed the relationship between physical activity and immune function. Key points discussed include:
- Adequate levels of physical activity have been shown to produce significant beneficial effects on various components of the immune system
- Overly strenuous physical activity can result in temporary suppression of key immune system components and create an open window for infection
- The beneficial effects to be gained from physical activity far outweigh any potential dangers arising from overtraining
- Levels of physical activity continue to decrease and much of this is due to changes in occupational demands and less physical leisure activity choices
- Finding ways to integrate physical activity into our daily lives can be significantly more beneficial then solely relying on short bouts of high intensity training