Firstly, hunger. People don’t just hit the gym café after a workout out of habit – cardiovascular exercise such as jogging, swimming and spinning classes increase hunger. This makes biological sense as you have of course just burned off a load of calories, (though, on that note, probably not nearly as many as you think compared to just going about your daily business; showering, getting kids up and dressed and getting ready for work burns calories too you know!).
However if your aim is to lose weight then replacing the calories you’ve just burnt is not going to help you progress! And here’s the thing with cardio; the hunger induced is not proportionate to the calories required to refuel, so you are actually very likely to eat more than you’ve just burnt off!
Cardio exercise also induces the release of stress hormones. Whilst these play an important role in survival (fight or flight) and body functions including inflammatory responses, glucose metabolism and immune functioning, negative effects of excess stress hormones can have negative effects on cognitive function, emotional wellbeing, cardiovascular health and bone density amongst other things, and to add to that in excess they burn muscle and store fat!
However cardiovascular exercise can of course be included in a healthy lifestyle, but you need to take actions to reduce the levels of stress hormones in your body if it is to be beneficial.
So what should you do if you want to burn fat? Resistance training, weights and intense workouts (short sprints rather than long jogs) build muscle, which in turn speeds up your metabolism and burns fat.
When combined with sufficient dietary protein, the stress hormone cortisol actually becomes your friend and encourages more muscle formation and repair rather than burning it. After exercising is also the time to eat starchy carbs to refuel your tired muscles and repair them, rather than before you work out when the food would be used as energy instead of burning existing stores.
And finally, walk as much as possible – it’s a little bit calorie burning, a little bit muscle building, and a lot of stress busting!