Even the most casual bodybuilder knows a little something about “protein timing” — but if you’re in need of a quick refresher, it refers to the distribution of protein throughout the day, and before/after training sessions, for optimal muscle protein synthesis. There are different studies and philosophies on how this should be accomplished, depending on your overall goals, and if you train regularly then you probably have a system down pat already.
But are you paying attention to “carb timing?” If you’re not, you might be putting yourself at a disadvantage when it comes to your health and physique. You’re also probably not alone, according to Gabrielle Lyon, D.O., a functional medicine physician specializing in muscle-centric medicine.
“The research for carbs and high-intensity exercise is very clear,” Lyon says. “The research about meal distribution for metabolic flexibility and body composition is not as well-established and definitely not widely-recognized.”
So why should you pay attention to how you distribute carbs throughout the day? It primarily has to deal with “metabolic flexibility,” or your body’s ability to adapt to different metabolic demands (aka the stress you put on it through eating and training).
We know that the consumption of any carbohydrates requires an insulin response so that our cells can absorb the sugars from the macronutrient for energy. Eat too many carbs, though, and your body might not be able to keep up.
“Research studies have shown that the body can use (burn) and store up to about 40 grams of carbs after a meal,” Lyon says. “Any meal that exceeds 30-40 g of carbs requires large insulin response that shuts down fat metabolism. This limits the body’s ability to burn fats, increases fluctuations in blood glucose and increases hunger.”
For the average person focused on keeping body fat to a minimum, Lyon recommends keeping carbs lower at the beginning of the day and higher at the end of it.
“The research has shown the first meal, breakfast, that limit carbs and increase protein maximizes metabolic flexibility for use of fatty acid fuels,” she says. “Carbs consumed at the last meal, dinner, have the least impact on metabolism and appetite.”
Of course, the strategy wouldn’t be the same for people who spend hours in the weight room and need plenty of energy for their training sessions. “Athletes focused on high-intensity performance may want more carbs earlier in the day,” Lyon says.
Keep in mind, that’s only for people who do intense training sessions — i.e. powerlifters or professional CrossFitters. “For routine training, normal meals are usually sufficient,” Lyon says.
But no matter what skill level you’re at, be sure your pre-workout carbs don’t involve foods high on the glycemic index (or foods that create a large spike in blood sugar), Lyon says.
Most people know that carb replenishment after a training session is vital to replace glycogen that’s been burned by the body. But Lyon says most gym-goers don’t have to stress too much about it. “For routine training, normal meals are usually sufficient,” she says.