The first question is Fuel used and figures. The predominant fuel used during the Cardio exercise we perform in the gym is sugar, of which is stored in the muscles and liver and converted to energy to provide our muscles with fuel. The harder we work the more sugar we burn.
Our body can store approximately 400 grams of sugar, that is 1600 calories, so the calorie read out you see on cardio machines will be virtually all calories from sugar. Some would be fat but very little.
So let's say you did 20 mins on the cross trainer burning 10 calories a minute, that's 200 calories, of which 80% was sugar. That's 160 sugar calories and say the rest was fat, that's 40 fat calories in 20 mins.
To shed a pound of fat you need to burn 3500 calories, that means you would need to do 29 HOURS ON THE CROSS TRAINER!!! Perhaps that's why 24 hour gyms are opening!
To be continued