Our study is observational, so we can’t conclude that physical activity causes people to be healthier, nor can we explain why exercise is beneficial. However, we were careful to control for factors that might otherwise explain the results. That is, physically active people may have more healthy lifestyles in general, such as a better diet, not smoking and may have better health. In order to make sure that poor health was not causing people to exercise less and die sooner, we discarded the data on anyone who died in the first two years of the follow-up period thus making the results more scientifically robust.
Quality of exercise may be important
Experimental studies suggest that exercise improves aerobic fitness and other important chronic disease risk factors. The weekend warriors in our study undertook a large proportion of vigorous-intensity exercise, and quality may be more important than quantity. Vigorous-intensity exercise improves aerobic fitness more than the same amount of moderate-intensity exercise, and two bouts of vigorous-intensity exercise a week are enough to maintain aerobic fitness.
We often hear about the dangers of weekend warriors being more at risk for injuries and health problems. So people undertaking exercise for the first time or after a period of inactivity should build up gradually. For example, begin with a moderate-intensity exercise like brisk walking. Brisk walking is associated with low risk of injury and it’s important to set realistic goals that provide motivation and build confidence. Middle-aged and older adults are recommended to take part in at least 12 weeks of moderate-intensity exercise before introducing any vigorous-intensity exercise.
So, the message is simple. Any activity is better than none - whether you spread it out or do it in one go. Move more, sit less.