03/20/2014
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 storage 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 are 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 that 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 that 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 that they look flatter and smaller than they could. Having muscles that 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 blood stream. You can use straight dextrose/glucose powder or Wonka Pixy Stix (100% dextrose) or gummy bears, which tend to be made out of dextrose and corn syrup. Corn syrup is essentially branched glucose molecules that are immediately broken down and absorbed. Corn syrup is completely different from high-fructose corn syrup. White bread and white potatoes are also good sources since they are mainly starch, which is branched glucose molecules bound together that breaks apart rapidly upon ingestion.
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.
Having fast carbs after workouts is a sweet treat that doesn’t damage your diet. Whether you are trying to maximize mass gain, or lose fat and gain muscle, you should be following a fairly “clean” diet. By that I mean that donuts, French fries, and ice cream are not major staples in your nutrition plan. When most of us stay fairly virtuous with our diets, we tend to miss those treats we have come to love such as sweets. Having a dose of sweets in the form of dextrose, gummy bears, Pixy Stix, or white bread with jelly is a great way to get your sweet fix in for the day and not only have it not ruin your diet, but actually enhance your results! Why would you ever skip that?
Some research shows that consuming a protein shake after workouts with or without fast carbs spikes muscle protein synthesis to an equivalent level. In other words, the studies concluded that adding carbs to a protein shake post workout did not increase muscle protein synthesis any more than the protein shake did alone without carbs. This has caused some experts to claim that you do not need carbs after workouts. Well, that’s a bit extreme. It’s true that you can still build muscle without having carbs after workouts. But I wouldn’t recommend that unless you are in a very low-carb diet and you have removed carbs from every other meal of your diet. In fact, it’s completely idiotic to eat carbs at other meals but avoid eating carbs post workout. If you are eating carbs at any meals, the most critical meal to eat them at is the post workout meal when they will aid recovery.
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 towards the end of the workout, depending on the workout. After the workout is over the levels of theses hormones begin to drop sharply so that they are back to resting levels about 60-90 minutes after the workout is over. The release of these hormones has 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 your ass 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. I would recommend limiting the fast carbs to about 60 grams for two main reasons. Reason one is that 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. If you’re consuming more than this I would actually recommend adding some fructose, such as from fruit to your post workout meal in addition to the dextrose or glucose. The second reason is that consuming too many fast carbs can make you feel like crap after its 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 that this happens to you even with smaller amounts of fast carbs, then I suggest that you mix your post workout carbs so that you are getting some fast carbs and some slow carbs, such as fruit, oats, whole-wheat bread, sweet potatoes, etc.
To Your Success,
Patrick Bailey MS, PES
