Scientists confirm that regular and moderate workouts will help strengthen the body during the season of diseases.
It is known that a healthy lifestyle affects not only the body as a whole but also the state of immunity. It is logical that the healthier and stronger a person is, the less susceptible he is to diseases and colds. However, what role does sport play in this? And is it possible to strengthen the immune system with the help of training?
How does exercise affect immunity?
Researchers at the University of Iowa, USA, conducted an experiment in 2009 to find out how exercise affects the immune system. Three groups of mice were selected for the study. The first group had no additional workouts. The second group has been moderately “engaged” in exercise for 14 weeks. The third group had a 45-minute “run” just before the experiment had started. Then all the mice were infected with the influenza virus.
The ISU researchers found that mice that regularly ran on a treadmill over a three-and-a-half-month period developed less severe symptoms from the flu virus than those that were not subjected to exercise, and had less influenza virus in their lungs. The mice that regularly exercised showed lower levels of inflammatory factors in their lungs soon after being infected with the virus.
We may suggest that a moderate workout per day may just keep the doctor away – or at least diminish the severity of the flu’s symptoms for humans as well.
Similar conclusions were made at the University of North Carolina. A group of 1002 adults between 18 and 85 years old took part in the study. They regularly reported how they were feeling for 12 weeks during the flu season. In addition, the subjects noted their level of activity. As a result, among those who exercised five times a week or more, symptoms of upper respiratory tract infection (URTI) were observed 43% less often than those who performed one or fewer workouts. Physical fitness and frequency of aerobic exercise correlate with reduced days of URTI and severity of symptoms during the winter and fall common cold seasons.
What kind of workout to choose?
To get the most positive effect all workouts should be moderate. This is confirmed by a series of experiments conducted at the University of Illinois in 2005. Scientists divided the experimental mice into three groups. The first group led a sedentary lifestyle, the second group – “practiced” for 25-30 minutes a day, and the third group – daily “trained” for 2.5 hours.
After infection with the influenza virus, of those mice that practically weren’t physically active 43% recovered, but in the second group 83% managed to overcome the disease. The least survivors (30%) were in the last group, which was subjected to intense stress.
Similar results are reported in the book by Alex Hutchinson “Which Comes First, Cardio or Weights?: Fitness Myths, Training Truths, and Other Surprising Discoveries from the Science of Exercise”. Researchers observed 2,300 runners who were training for the Los Angeles Marathon. It turned out that for those who in training ran more than 59 miles a week the risk of catching a cold was higher.
Why intense exercise can harm?
It is not known for certain why intense workouts have a bad effect on the immune system: intense exercise temporarily weakens the body, slowing the immune response. Although moderate exercise can help delay inflammation and improve your ability to respond to other stresses, such as influenza, as mentioned before.
In 2016, a group of scientists found that intense training for two days in a row leads to a decrease in immunity. After two consecutive days of Crossfit training, the subjects showed a reduced content of cytokines – anti-inflammatory cells.
Exercise can actually strengthen the immune system and help reduce the risk of getting infected during the flu season. However, to be beneficial and not harmful, it must be regular and moderate, and the importance of recovery time should not be forgotten.
TAGS: plan training, moderate training, sports affect immunity