Originally Posted by Snicklefritz
Thanks for the reply. That does help because it would seem that breaking things up into 3 essions would probably not be very effective. When breaking things up into two sessions, do you think there would be much difference between 45/45 or 60/30?
...it's kinda too comples to answer on the internet, because factors of exercise intensity, your diet,
your current state of conditioning, andd some other stuff are all in play.
Fat and carbohydrate are the two major energy sources used during exercise. Either source can predominate, depending upon the duration and intensity of exercise, degree of prior physical conditioning, and the composition of the diet consumed in the days prior to a bout of exercise. Fatty acid oxidation can contribute 50 to 60 per cent of the energy expenditure during a bout of low intensity exercise of long duration. Strenuous submaximal exercise requiring 65 to 80 per cent of VO2 max will utilize less fat (10 to 45 per cent of the energy expended). Exercise training is accompanied by metabolic adaptations that occur in skeletal muscle and adipose tissue and that facilitate a greater delivery and oxidation of fatty acids during exercise. The trained state is characterized by an increased flux of fatty acids through smaller pools of adipose tissue energy. This is reflected by smaller, more metabolically active adipose cells in smaller adipose tissue depots. Peak blood concentrations of free fatty acids and ketone bodies are lower during and following exercise in trained individuals, probably due to increased capacity of the skeletal musculature to oxidize these energy sources. Trained individuals oxidize more fat and less carbohydrate than untrained subjects when performing submaximal work of the same absolute intensity. This increased capacity to utilize energy from fat conserves crucial muscle and liver glycogen stores and can contribute to increased endurance.
If you read this Wikipedia link, it should help you to figure it out for yourself, depending on your goals.
Generally speaking, the longer you spend in the aerobic portion of your exercise
period or periods, the better you will meet the goals you stated in your OP.
Look at it from the standpoint of every time you stop, rest, and then start up
another period later on, you have to go through an anaerobic period, which does
not lend itself to what you said you wanted. A 30 minute session for a person
in reasonable conditioning hardly gets into the aerobic phase at all.