Light physical training is the best way to enhance the immune system of people beginning an exercise program for the first time, according to a study by a University of Toronto professor.
In a comparison of the immune responses of previously sedentary men placed in either a light or moderate exercise program, Professor Emeritus Roy Shephard of the Faculty of Physical Education and Health found that light training has the strongest protective effect. Blood samples from the men revealed that while both the light and moderate programs increased some immune activity, the moderate training was less efficient overall.
"The results indicate that when it comes to improving immunity in sedentary young adults the optimal training regimen is one of low volume," Shephard said. Compared to light physical activity, the moderate program produced a smaller increase in specific killer white cells and actually reduced the B cell count, which can have a negative impact on the production of antibodies.
The 33 inactive men aged 19 to 29 were in similar physical condition when they began the 12-week program. Those in the moderate group jogged or cycled four to five times per week while the light training group performed the same exercises only three times per week on alternate days.
Published in the Journal of Sports Medicine and Physical Fitness, Shephard's research was supported by grants from the Defence and Civil Institute of Environmental Medicine and Canadian Tire Acceptance Limited. Shephard's co-authors are Susan Shore and Shawn Rhind of the Defence and Civil Institute of Environmental Medicine and Shoji Shinkai of the School of Public Health at Ehime University in Japan.
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Journal
The Journal of Sports Medicine and Physical Fitness