Efficiency is very important in modern life, and fitness is no exception. We all want our workout time to produce the best results. For most of us, that means controlling weight and improving general health by burning calories.
Which exercises do this best, and how do we know?
A calorie is a unit of heat, but it is tricky to measure extra body heat output. Work done during the early 20th century showed that oxygen used and carbon dioxide produced relates directly to calorie burn. Even more importantly, measuring these gases shows the ratio of calories sourced from carbs or from fat stores.
Volunteers pedalling stationary bicycles while wearing masks have allowed researchers to find out how many calories are used by exercise. This data also calibrates fitness trackers, which measure what you do and how long you do it rather than actual calorie use.
The two main factors are the amount of muscles used and the time for which they are used.
Working muscles demands oxygen, and that burns calories. The bigger muscles of the lower body are great calorie burners, with running and cycling also likely to go on for longer than more intense exercise.
Not necessarily, for two reasons. Firstly, studies have shown that adding arm exercises can actually reduce overall oxygen use over using lower body alone. Secondly, letting muscles groups rest gives you more chance of more frequent workouts, and that’s what really deals with calories.
A tough workout can leave your body in ‘oxygen debt’, and working harder even after you stop working hard. This effect is called the after-burn. It does use up a few extra calories but probably not enough to make a difference.
The best of all worlds is a longer workout at the highest intensity that you can manage. As always, the workout must also be one you enjoy to ensure that it actually happens.
I always knew my cycling was a big calorie burner, even if I didn't use my arms.
So this is saying that a cross-trainer probably isn't worth the effort. Guess i'll stick with the bike then!
The one piece of exercise equipment I own at home is a stationary exercise bike for the simple reason that it works the biggest muscles in the body and I can burn loads of calories on it