7: Use fast carbs right after workouts
During workouts, you are burning through muscle glycogen like a rap star burns through his bank account. Glycogen is the stored form of carbs. In simplified terms, when you consume carbs, most are broken down into or converted into glucose, which is what blood sugar is. Glucose can either be used fairly immediately for fuel or stored, mainly in muscle fibers and the liver. It is stored in the form of glycogen, which is just long, branched chains of glucose connected together. The glycogen in your muscle cells and liver is broken down into glucose and used as one of the main fuels to fuel your workouts. At the end of a workout, your muscle glycogen levels are depleted. If your muscle glycogen levels are not restored, your performance in the next workout can suffer, and muscle growth may be compromised.
One way muscle growth can be compromised is due to the fact that muscle glycogen levels serve as a barometer for how much energy the body has stored. If energy levels are low, as it seems when muscle glycogen is low, then the muscles may not want to expend energy building muscle. Building muscle requires energy, and bigger muscles require more energy to maintain. If your body is unsure that you have adequate energy to fuel other, more critical processes, and to maintain more muscle mass, it may choose not to go gangbusters building muscle.
Another way muscle growth may be compromised is due to the fact that glycogen pulls water into the muscle fibers. The more glycogen, the more water in the muscle fibers. More water makes the muscles fuller. This makes your muscles appear significantly bigger. If your muscles are low in glycogen, then they are also low in water, and that means they look flatter and smaller than they could. Having muscles that are fuller due to more glycogen and water can also instigate muscle growth. There is evidence that having more water in the muscle fibers places a stretch on the muscle membranes and that stretch instigates chemical pathways that increase muscle protein synthesis, which can lead to greater muscle growth.
The best way to fully replenish muscle glycogen is with high-glycemic or fast-digesting carbs. These carbs make it into the bloodstream and to your muscle fibers almost as quickly as you ingest them. Research confirms that the quicker you get carbs to your muscles after workouts, the faster and better the muscle glycogen replenishment. One of the best sources of fast carbs is dextrose, which is glucose. This form of sugar requires no digestion and is absorbed pretty immediately into your bloodstream. You can use straight dextrose/glucose powder or Wonka Pixy Stix (100% dextrose) for example. White bread and white potatoes are also good sources since they are mainly starch, which is branched glucose molecules bound together that break apart rapidly upon ingestion.
We’re not saying eat a lot of sugar or white bread, but after your workout is a good time to get 20-40g of simple sugar. These fast carbs also spike insulin levels. After a workout is the ONE time of day when you want to spike the anabolic hormone insulin. Research shows that insulin is critical for pushing creatine and carnitine into muscle fibers. Without a big spike in insulin, creatine and carnitine uptake are not optimal. Insulin also helps amino acids, such as beta-alanine, BCAAs, and the other critical ones from your protein shake get taken up by the muscle fibers. And let’s not forget about the glucose from those fast carbs, which insulin helps to gain entry into the muscle fibers. For more info on these supplements, see Rule #8 below.
Some people worry that eating carbs post-workout will blunt growth hormone and testosterone levels after the workout. Here’s what they don’t understand. Growth hormone and testosterone levels rise during the workout and peak toward the end of the workout, depending on the workout. After the workout is over, the levels of theses hormones begin to drop sharply so they are back to resting levels about 60-90 minutes after the workout is over. The release of these hormones have already peaked before you consume those carbs. After the workout is over, it’s too late for the carbs to have a negative effect on hormone levels.
Some people worry that consuming fast carbs after workouts will lead to diabetes. This is due to the media’s demonization of all sugars. Yes, if you are eating sugars while sitting on the couch all day, it will increase your risk of developing type 2 diabetes. But someone who trains regularly is already preventing the metabolic damage that leads to type 2 diabetes. And right after a workout is when those carbs are going straight to the muscles and restocking the muscle glycogen, as well as the liver glycogen levels. So there is no risk to consuming fast carbs after workouts. It’s what your body needs.
Although the amount of fast carbs you consume after a workout depends on your weight and the intensity and length of the workout, a general recommendation is to shoot for about 20-40 grams worth of fast carbs such as dextrose within 30 minutes after the workout is over. Research shows that for optimal absorption by the intestines, 60-70 grams of one type of carb is the maximum before absorption by the intestines becomes limited. A second reason that you don’t want to consume too many fast carbs is that it can make you feel like crap after it’s all been quickly taken up by the liver and muscles and your blood glucose levels drop. This is known as hypoglycemia and can make you feel dizzy, lethargic, and just generally crappy. If you find this happens to you even with smaller amounts of fast carbs, then we suggest you mix your post-workout carbs so you are getting some fast carbs and some slow carbs, such as fruit, oats, whole-wheat bread, sweet potatoes, etc.