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[[File:Insulin sensitivity and exercise without nutrition.jpg|none|thumb|500px|How exercise increases insulin sensitivity, but without nutrition the sensitivity disappears and they actually become insulin resistant.]]
==What fuel?==
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.
[[File:Plasma Insulin Response.jpg|none|thumb|500px|The rate of plasma insulin response 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).]]
== The Nutrient Timing System Summary ==
The Nutrient Timing System (NTS) is designed for strength rather than endurance athletes.
=== NTS During Exercise===
Taking protein with carbohydrate can reduce the damage to muscles and support the immune system. The ratio of 1:4 protein to carbohydrate has been shown to be effective, though other ratios from 1:2 to 1:6 also work.
===NTS Immediately after exercise===
Taking a carbohydrate/protein mix immediately following exercise can helpimproves recovery and muscle synthesis. Again 1:4 has shown to be effective, but other ratios also work. John Ivy's book recommends 15 grams of whey protein with 50 grams of carbohydrate, providing 220-260 calories. This should be easily digested so that it can be used by the body quickly. This should be taken within 40 minutes of completing the exercise and ideally as soon as practical after finishing the exercise.
===NTS Post Exercise ===
From 1-4 hours after exercise, continued fueling can maintain the muscle's sensitivity to insulin. Using a ratio with more protein and less carbohydrate is generally recommended. John Ivy's book recommends 14 grams protein to 2-4 grams carbohydrate taken within 4 hours of exercise.
* My body weight has increased slightly and my body fat has decreased. I am seeing this decrease using skin fold calipers, the mirror and the 'jeans fit' methods ;}
* I suspect my calorie intake for the rest of the day has decreased somewhat as my appetite has lowered. Following [[Book Review - The end of overeating|'the end of overeating']] has helped curb my excessive intake.
* Protein My protein intake has gone from about 160-200 grams (2.5g/Kg-3.2g/Kg) to about 300+ grams (4.8g/Kg) on training days. This is higher than the highest recommendations for protein intake. However, as a percentage of calories, this is probably somewhat reasonable (300 grams is 1200 calories, with a 4000 calorie diet is 30%).