Post-workout nutrition normally focuses on what protein to have and when it is best to have it.
This is because of the importance of muscle protein synthesis (MPS) and in fairness consuming protein is the most important thing to do after a workout. But there is another macronutrient that is required post-workout and that macro is carbohydrates.
The reason why carbohydrates are important for post workout nutrition are:
- To allow the release of insulin which has an anabolic effect (it helps build muscle)
- To prevent cortisol being released, this is a hormone that has a catabolic effect on muscle (it breaks it down for energy)
The type of exercise that you are performing will have an influence on whether you require carbohydrates post workout or not.
For example, a high intensity exercise session will use up a lot of your available energy (known as glucose) and the stores of energy (known as glycogen).
When this happens you will need to take carbohydrates pretty soon afterwards because when your body runs out of both glucose and glycogen it releases Cortisol (the stress hormone) which leads to the catabolism of muscle tissue.
If your exercise activity was low in intensity you will not have run out of glucose or glycogen which means that the need for extra carbohydrates will be lessened.
There are still benefits to consuming carbs however as your muscles will benefit from the release of insulin.
Insulin has been found to increase glucose metabolism and improve peak VO2 after physical exercise in a study by Sato et al (1986) .
It has also been shown to improve muscle protein synthesis by improving the transport of amino acids within skeletal muscles .
So if you have been lifting heavy weights, a post-workout carb intake could help your recovery and hypertrophy.
What Carb choices should I go for?
The type of carbohydrates that you want after a workout are the ones that you've been told to avoid all your life.
Fast-digesting carbohydrates that are high in sugar (also known as simple carbohydrates) seem to have the greatest effect. Some experts do recommend starchy carbs such as potatoes but they are in the minority.
Regarding fructose, that is found in fruits this is a common choice for post-exercise nutrition but may not actually be ideal.
Fructose isn't able to turn directly into glucose and as a result won't benefit you as much. It doesn't get digested quickly and it doesn't raise insulin much either so as a post-workout carb source fruit is sub-optimal.
The most common carbohydrate used in the supplement industry is Dextrose, this is because Dextrose has a high glycaemic index, which means it gets digested fast.
It comes in the form of powder which means that it can be mixed into protein shakes very easily. In fact many supplement companies mix dextrose directly with whey protein for a powerful post-workout shake.
A surprisingly good source of Dextrose is common sweets, particularly Gummi bears.
Experts such as Jim Stoppani recommend Gummi bears post-workout for this exact reason. As you are coming straight from a high-intensity workout and your Glycogen levels are low you should be fine to eat them without the carbohydrates turning into body fat.
So what should I take Post-workout?
A whey protein shake is always a good idea, as is a serving of Dextrose. Combining the two seems to have a synergistic effect, in other words the two together seem to produce a greater response than they would separately.
A study by Bird, Tarpenning, & Marino (2006) found that liquid carbohydrate combined with essential amino acids (protein) produced a greater anabolic effect on muscle than either did alone . However a study by Miller et al (2003) found that the results were comparable but not greater .
Either way it seems like a good shout to combine both whey protein and dextrose as a post-workout meal.
You could try buying a whey protein supplement that already contains Dextrose, or buy Dextrose separately (it's sold at most supplement sites) which usually works out cheaper.
Other ways to do it would be to have a protein shake and then eat your high Dextrose Gummi Bears.
If the idea of sweets really doesn't appeal to you then fruit would be an okay replacement, if not as effective it would help increase the amount of vitamins and minerals in your diet.
Oats are also a good shout, either in powder form (again available from most supplement companies) or just steal cut oats from the supermarket or health food store.
If you don't have any carbohydrates available after your workout don't panic! Whilst an immediate supply of carbs is ideal for both glycogen replenishment and insulin release, having your carbs an hour or two later should still prevent catabolism. Particularly if you've had a pre-workout meal which would have increased your available glycogen prior to working out.
 Sato, Y., Hayamizu, S., Yamamoto, C., Ohkuwa, Y., Yamanouchi, K., Sakamoto, N. 1986. Improved insulin sensitivity in carbohydrate and lipid metabolism after physical training. International Journal of Sports Medicine 7(6): 307-10
 Bonadonna, R., Saccomani, M., Cobelli, C., DeFronzo, R. 1993. Effect of insulin on system A amino acid transport in human skeletal muscle. The Journal of Clinical Investigation 91(2): 514-21
 Bird, S., Tarpenning, K., Marino, F. 2006. Independent and combined effects of liquid carbohydrate/essential amino acid ingestion on hormonal and muscular adaptations following resistance training in untrained men. European Journal of Applied Physiology 97(2): 225-238
 Miller, S., Tipton, K., Chinkes, D., Wolf, S., Wolfe, R. 2003. Independent and Combined Effects of Amino Acids and Glucose after Resistance Exercise. Medicine & Science in Sports & Exercise 35(3): 449-455