mikesbytes wrote:OK when I race I consume energy gels to keep me (for want of a better word) spiked, but what are the energy gels actually doing for me? Are they causing an insulin response and if so how is that helping me
Ok, I'm not a biochemist but here is my understanding. Insulin is one part of the equation along with blood glucose. My simplistic understanding is this: you consume the energy gel which is absorbed and enters your bloodstream as glucose? In response to higher blood glucose, your pancreas secretes insulin which enters your bloodstream.
Although there is always a low level of insulin secreted by the pancreas, the amount secreted into the blood increases as the blood glucose rises. Similarly, as blood glucose falls, the amount of insulin secreted by the pancreatic islets goes down.
This is normal blood glucose regulation and demonstrates the insulin response you are asking about. What is it for?
...insulin has an effect on a number of cells, including muscle, red blood cells, and fat cells. In response to insulin, these cells absorb glucose out of the blood, having the net effect of lowering the high blood glucose levels into the normal range.
In your case, taking a gel during exercise, presumably the insulin stimulates muscle cells to take up glucose for energy.
Of course it is more complex than that...
http://www.endocrineweb.com/conditions/ ... od-glucose
There is recent research on the impact of different types of foods on circulating insulin and blood glucose levels which found that:
...postprandial insulin responses are not always proportional to blood glucose concentrations...
It's well worth a read if you want to know more about how different foods increase levels of insulin and blood glucose respectivly but not proportionately. Presumably for intense exercise you would want a high glucose response and a higher insulin response to stimulate your muscle cells to uptake the glucose. For example in the study, porridge (which we would associate with slower energy release) had a glucose score of 60 and an insulin score of 40. I would have porridge before a long ride for sustained energy release. On the other hand jellybeans (which we would associate with quick energy) had a glucose score of 118 and an insulin score of 160! I would more likely have jellybeans in a race for a fast but shorter energy hit. Although, jellybeans are a bit inconvenient when racing, hence the gels.
Link to the study here:
http://ajcn.nutrition.org/content/66/5/1264.full.pdf
Hope this helps.