How much carbohydrate should I consume after exercise?

I’ll cut to the chase here. You need around 1g carbohydrate/kg of bodyweight immediately after exercise has ended. So the average 70kg athlete would require 70g of carbohydrate straight after training.

And after that….

After intensive training your body enters a period, which lasts around 6 hours, where the rate of glycogen replenishment is increased. It has 3 stages

0-2 hours after training – replenishment is approx 150% the normal rate

2-6 hours after training – replenishment slows down but still faster than normal

6+ hours after training – replenishment is back to normal

So clearly, refilling glycogen stores (with carbohydrate) would be very beneficial during this period.

Why is glycogen replenishment faster during this period?

Firstly, eating carbohydrate stimulates insulin release, which in turn, increases the amount of glucose taken up by the muscle cells from the bloodstream, and stimulates the action of the glycogen – manufacturing enzymes. Secondly, post-exercise, the muscle cell membranes are more permeable to glucose so they can take up more glucose than normal.

So what would be the ideal carbohydrate plan for after training?

Immediately after – 1g carbs/kg of bodyweight

1-2 hours later – 50g carbs (minimum)

1-2 hours later – 50g carbs (minimum)

The above is a guideline and some trial and error may be necessary. At the end of the day we’re all different and we all have different goals. Anyway the above plan would have the average athlete consuming around 170g of carbohydrate during the 6 hour period.

Are high GI or low GI carbohydrates best for recovery?

Since high GI foods cause a rapid increase in blood sugar levels, it seems logical that high GI foods would increase glycogen replenishment, during the initial post-exercise period. A shed load of studies have backed up this fact. So science suggests that high GI would be the way to go post-workout. Unfortunately it’s not as simple as that.
This is because after 24 hours, regardless of whether you’ve eaten low GI or high GI foods, muscle glycogen storage is about the same. So although high GI foods get you off to a fast start, low GI foods will result in the same level of recovery 24 hours after exercise. There are also performance benefits of a low GI recovery diet – it may improve your endurance the following day. So if you’re training every day, low GI may be the right way to go.

So what should I do?

The best thing to do would be to consume high GI foods during the first 2 hours after exercise. The remainder of your post-exercise recovery should be made up of /low GI foods. Once the 6 hour window has expired, you should be consuming low GI foods as normal.

So...

0-2 hours after exercise - 1g carbs/kg of bodyweight (high GI)

2-4 hours after exercise - 50g of low GI

4-6 hours after exercise - 50g of low GI

6+ hours after exercise - normal diet resumes.