Orange is the new black, 40 is the new 20, and exercise is the new prescription. If today’s health is the result of yesterday’s habits, then incorporating regular exercise is a must. Learn how to boost your immune system with today’s excerpt.

The more physically fit and active you are, the less likely you are to suffer colds in the winter months.

That’s the conclusion of US researchers, who studied about 1000 adults and found those who exercised the most were least likely to suffer from colds in the winter months.

The researchers, from the Appalachian State University and the University of North Carolina, have published their results online in the British Journal of Sports Medicine. They followed a group of 1002 healthy adults aged from 18 to 85 years, over a 12 week period during the US autumn and winter seasons in 2008.

At the beginning of the study, the subjects were examined, and questioned on their diet and lifestyle, including how much exercise they did and how fit they perceived themselves to be.

Then, every day over 12 weeks, each participant reported any symptom of respiratory illness they experienced (such as sneezes, coughs, fever or other symptoms) and its severity, according to a standardised scale called the Wisconsin Upper Respiratory Symptom Survey.

Over the 12 weeks, the subjects reported experiencing symptoms of an upper respiratory tract illness (URTI) on average for 13 days in the winter and 8 days in the autumn.

But those who were fit and exercised frequently were much less likely to develop a cold, and when they did, it was much less severe.

Those in the top quarter for fitness levels (who did five or more days of exercise a week) experienced 43 % fewer days with URTI symptoms than those in the lowest 25 % of fitness levels (who did one day or less of exercise).

And when they did get cold symptoms, the symptoms were less severe. URTI symptoms were 32 % less severe in the top 25 % of exercisers compared to the bottom 25 %.

Source: “Study proves exercise boosts immune system.” By Peter Lavelle.