8,153
edits
Changes
From Fellrnr.com, Running tips
m
no edit summary
Muscles are continually being broken down and rebuilt, and the balance between this breakdown and synthesis is the net change in muscle. In a fasted state, the rate of breakdown exceeds the rate of synthesis, and we're losing muscles. (This is why [[GOMAD Grazing]] takes a continuous feeding approach.) After exercise, but before refueling, the rate of breakdown is higher, but the synthesis has gone up even slightly more than the rate of breakdown, so there's still a net muscle loss, just not as fast. Taking carbohydrate after exercise will reduce the rate of breakdown, but does not increase synthesis, so it's still a net muscle loss. It's only when the fueling includes protein that the rate of synthesis exceeds the rate of breakdown.
[[File:Muscle breakdown and synthesis.jpg|none|thumb|500px|The rates of muscle breakdown and synthesis in different states. (The units are arbitrary.)]]
If you look at [[Glycogen]] synthesis, taking protein and carbohydrate replenishes [[Glycogen]] faster than without the protein. However, taking the same number of calories of carbohydrate as in the protein and carbohydrate scenario actually produces greater [[Glycogen]] replenishment. So for maximal [[Glycogen]] storage, pure carbohydrates are best. However, this is not normally our objective unless we are [[Carbohydrate Loading ]] before an event.
[[File:Muscle Glycogen Synthesis.jpg|none|thumb|500px|The rate of muscle glycogen synthesis for 0.8 g/Kg of Carbohydrate (Carb), 0.8 g/Kg of Carbohydrate and 0.4 g/Kg of Protein (Carb + Pro) and for 1.2 g/Kg of Carbohydrate (Carb + Carb).]]
If we look at the insulin response to the same scenarios, we see that carbohydrate and protein has the greatest impact. This insulin will act as a growth hormone and helps boost muscle synthesis.
{| {{table}}
| align="center" style="background:#f0f0f0;"|'''Time'''
| align="center" style="background:#f0f0f0;"|'''[[Protein]]'''
| align="center" style="background:#f0f0f0;"|'''Fast Carbs'''
| align="center" style="background:#f0f0f0;"|'''Slow Carbs'''
