[eastcoastsurfer]

Originally Posted by Terra Nova

1. Do these values suggest that if, for example, I got up one morning and ( assuming my blood sugars were stable ) if did a fasted session of 30 minutes of moderate intensity cardio that the glucose in my blood would only provide about 2 minutes of glucose energy to fuel the cardio ? The vast majority of fuel during the 30 minutes is therefore provided by a combination of fat and glycogen I assume ? .

2. Assuming my blood sugar was bit low in the morning, if I had a light morning snack of 100 - 150 calories about 45 minutes +/- before my 30 minutes of moderate intensity cardio ...to boost it a bit....,theoretically speaking, I assume I could then stil derive much more than just 2 minutes of glucose to fuel the cardio due to having a light pre-workout snack ? In other words, the pre-work snack serves to not only stabilize blood sugar but to ' spare ' the burning of fat and glycogen to some extent as well ?

While I think I understand the role of blood glucose to sustain brain function and various other 'non exercise ' needs and the role of the fat stores and glycogen stores to fuel exercise, I don't think I have a solid grasp of the extent to which blood glucose fuels exercise.

Anyone's thoughts toward shedding some light on this for me would be greatly appreciated.

Thanks !

I'm no expert, but I did watch this show on Discovery a few weeks ago about the human body. One of the key take aways for me wast that it takes time for the body to switch over from one fuel to another. Experienced marathon runners and the like can switch over to using fats as fuel quickly and without much notice. People who are not experienced can take longer to switch over and may not be able to keep up the exercise while the switch is taking place. Just something else to think about