Nutrient Timing Part 2: Carbohydrates

Carbohydrates are probably the most misunderstood macronutrient in the fitness community. As many myths as there are floating around, it’s no wonder that misinformation has become the standard and taken as fact. For our purpose right now, the topic of carb timing is what we will be exploring.

Before we dive right into the fun stuff, a few points need to be addressed in regards to carbohydrate sources. By now, most of us should know that the Glycemic Index (GI, it is food‘s ability to raise blood sugar) is all but irrelevant unless perhaps you are a bed ridden diabetic with Metabolic Syndrome. The studies that show that GI could make a small difference in training/favorable body composition response are poorly done at best, with participants that are overnight fasted and fed ALL high GI or ALL low GI foods. Neither of which matches the habits of someone in the fitness community.

Most individuals who are involved in a regular weight lifting/cardio regiment eat with 2 commonalities, 1.) They eat multiple times a day, typically spread out fairly evenly 2.) They eat balanced meals containing all 3 macronutrients. Most of the day is spent in the postprandial period with glycogen available in the liver and muscle cells for use.  Because of this, it should be stated that in the hierarchy of importance the total amount of carbohydrate is ultimate and the timing of carbohydrates is far below. However, there is some benefit to placing carbohydrates at certain times of the day.

Breakfast: This is typically one of the hot times to consume carbohydrates for a variety of magical reasons. The truth of the matter is that consuming carbs at the time isn’t going to do anything extra for switching off protein breakdown or increasing protein synthesis.  There are good reasons however to eat carbohydrates at breakfast, those include providing fuel (though already stored in liver and skeletal muscle) for the brain and body, taste, and the fact that you have a million traditional breakfast choices that revolve around carbs.

Pre Workout:  Immediately pre workout It is advisable to include a quick absorbing protein like whey or egg whites, especially if it has been a while since your last meal and serum albumin levels will be down. With that protein, a carbohydrate that will provide some aid in the energy expenditure during the workout would be advisable, something more complex that will take longer to break down would be a good choice, especially if the meal you ate last was quite some time ago. Fat shouldn’t be in your preworkout in any large amount (above 15 grams) due to the blood needed for digestion and fat slows emptying of the stomach, slower digestion and more blood needed in the gut.

Post Workout: It only takes an insulin concentration of at most 30 mU/l to inhibit muscle protein breakdown, which can easily be accomplished by whey protein mixed in water. However, if pre workout nutrition (that is food all day up until the training bout) is adequate then the purpose of post workout nutrition is no different, simply to maintain levels of hydration, blood glucose and amino levels as well as increase protein synthesis. All of which occur in the 24 hour day at about equal levels, not just post workout.

Bed time: No carbs after 7:00 P.M. has been an idiotic recommendation for quite some time now, causing many frustrated athletes to opt for plain cottage cheese over some popcorn or a reasonable amount of ice cream.  It is 24 hour energy balance that matters when dealing with muscle gain or fat loss, the timing of the nutrients is not very relevant.  If you train near the early morning after just 1 or 2 meals, it would make sense to have a larger portion of your carbohydrates at night right before bed so that glycogen stores are ready to go in the morning.

To wrap this all up, going to state once more that overall carb consumption is vastly more important than the timing of those carbohydrates. It is most practical to have carbohydrates in the meals that are convenient and you find you feel the best and perform the best.