Notes: Pre & Post Workout Nutrition (and a bit on Carbs)

Here's a couple of the things I noted down a few days ago while listening to episode #73 of the Tri Talk Triathlon podcast on the subject of nutrition needs around a workout.

Pre-workout (only if +60 minutes long):

• 2 to 4 hours before: 500 kcals of healthy carbs
• 60 minutes before: 1 gr per kg of body mass (4 kcals/kg)

Post-workout (only for intensive workout; e.g. +3hrs bike ride):

• if less than 6 to 8 hours to recover (to top-up glycogen level before another workout)
• carbs: 1.2g per kg of body mass per hour (+60 glycemic index, up to 5hrs post workout)
• proteins: 0.6g per kg of body mass per hour
• if more than 6 to 8 hours to recover
• eat when convenient (no need for high glycemic index)
• top off glycogen level like above, but no need to do it every hours

If you are a n00b when it comes to nutrition, like myself, this beg for some background explanations (disclaimer: I'm no nutritionist, I'm just an idiot trying to make sense of what I read! Please correct me when I'm wrong): 

Carbs refers to any food that is rich in complex carbohydrates (e.g cereals, bread, pasta ...) or in simple carbohydrates (e.g. fruits, sweets). A carbohydrate is basically sugar (glucose & fructose) used by the body as stored energy. The Glycemic index indicates how quickly a particular carbohydrate is absorbed. Therefore, consuming a high glycemic index carbs allows for the body to re-load glycogen in the muscles (and liver) faster. 

Glycogen is synthesised by the body from the sugar present in the blood and stored in the liver (for use by the body) and in the muscles (for their sole usage). It is only when the liver and muscles are at their maximum capacity than the body will turn glycogen into fat. Carbs with low glycemic index (e.g. fruits, vegetables, whole wheat pasta, grains) consumed 12 to 18 hours before an event will be stored as glycogen instead of fat (see carbo-loading). However, as Fructose is ineffective at raising muscle glycogen levels, a meal high in glucose should be preferred (e.g pasta, bread, rice, potatoes).

The University of Sydney has a web site dedicated to Glycemic Index, with an handy way to find carbs with high (or low) glycemic index.