It’s easy to feel virtuous after working out, but it won’t save you from the modern disease of simply sitting down too much.

Smashing yourself at the gym for an hour, then spending the rest of the day stuck in front of your computer or slumped in your favorite armchair watching television, is like being a marathon runner who smokes.

And just like smoking, sedentary behavior is bad for you, regardless of whether or not you exercise.

Now, don’t get me wrong. Exercise is really good for you and helps reduce the incidence of nasty things like cardiovascular disease and diabetes. But new research suggests that just because you ticked the exercise box for the day, it doesn’t prevent the detrimental effects of being inactive for long periods.

Studies in recent years have shown a clear association between prolonged periods of inactivity and morbidity (disease) and mortality (death), both of which I’d rather avoid. And, due to advances in technology, being inactive has become one of our most popular pastimes.

For those of us who exercise regularly, we read this and think – those sedentary people need to get active. However, if you’ve been sitting down reading Fit Planet for longer than an hour – you are one of those sedentary people, regardless of whether you exercise.

A 2008 study looked at hours of television watched by adults who achieved the recommended hours of weekly exercise. They found that despite the regular bouts of exercise, time spent in front of the TV still increased cardiometabolic risk factors such as waist circumference, blood pressure and glucose levels. Further to this, a more recent study found that people who participate in more than seven hours of moderate to vigorous exercise per week BUT who also watch more than seven hours of television per day had twice the risk of cardiovascular mortality as those who do the same amount of exercise but only watch one hour of television per day.

So the message is pretty clear, exercise – yes absolutely – but don’t think you can then become a sloth for the rest of the day.

I’m always shocked to see people I work with take the lift instead of the stairs because they think they get enough activity due to regular appearances at the gym. That’s like being a weightlifter who gets the hotel porter to lift his luggage!

We’ve manipulated our environment to such an extent that it’s rare that we need to exert any effort to function in our daily lives. In my opinion we need to take the opportunity to be active at every chance we get.

Speaking of which – I’ve been sitting here writing this for too long – time to get up and chase a squirrel.

(For more insight on the dangers of the sedentary lifestyle, read on.)

Bryce Hastings is a leading New Zealand physiotherapist and fitness expert. As Les Mills Head of Research he leads research into the most effective approaches to exercise and plays a pivotal role in structuring all LES MILLS™ workouts. Bryce’s passion for effective exercise is born from spending 30 years in physiotherapy, where he saw “people getting their lives wrong” every day and felt like he was acting as an ambulance at the bottom of the cliff. By working in fitness he gets to be the fence at the top.