Tyler Robbins Fitness

B.Sc. Biochemistry, Certified Strength and Conditioning Specialist (CSCS), Certified CrossFit Trainer (CCFT/CF-L3), USA Weightlifting Level 1

Day 114 - Nutrient Timing for Resistance Exercise Part 2

Part 1 the other day covered nutrient timing prior to exercise, and how it effects performance. Today will cover nutrient timing following exercise.

For those of you who may have missed part 1, I came across an absolutely amazing article in the Strength and Conditioning Journal titled, "Nutrient Timing for Resistance Exercise" written by a team of PhD and CSCS certified individuals. This is probably the single-greatest resource I have come across detailing what is referred to as "nutritional timing" when it comes to resistance training, so if you are interested, pick up a copy for yourself!

Part 2: Recovery After a Resistance Exercise Bout

Carbohydrate and Muscle Glycogen Resynthesis

It is no surprise that muscle glycogen levels become depleted from a resistance training session. The level of depletion is entirely dependent on the work being completed, however. In any respect, an athlete who trains multiple times a day, or even multiple days in a row, should be interested in post-workout nutrition.

In order to maintain performance, an individual should approach post-exercise nutrition as a chance to re-fuel their muscles to prepare for the following workout. Keep in mind that for muscle glycogen replenishment, the goal is to maintain a high level of performance. A discussion on protein synthesis can come later.

To return muscle glycogen levels to 90% of pre-exercise values, the article explains:

Given that 1 g/kg/h was as effective as 1.5 g/kg/h, it can be concluded that 1 g/kg/h is sufficient for resynthesizing skeletal muscle glycogen after resistance exercise to levels reaching 90% of pre-exercise values. After this dosing schedule, a 180-pound individual would ingest about 82g of carbohydrate immediately after and then again 1 hour after their resistance exercise workout (totalling ~165g of carbohydrates within an hour after completing the resistance exercise workout).

Carbohydrate Plus Protein and Muscle Glycogen Resynthesis

This category takes things a step further as the subject of protein synthesis is added to the goal of restoring muscle glycogen levels.

The authors discuss findings from studies looking at various types of post-workout beverages including carbohydrates only, carbohydrate/protein/fat mixes, as well as placebo beverages (calorie-free).

To be honest, I have heard many individuals discuss the idea that dietary fats should be avoided in post-workout recovery beverages/meals, as the fats can slow digestion. This appears to me to be common thought/practice amongst many in the fitness industry, however, the authors of this article present findings that refute that belief.

Another interesting aspect of this study is the inclusion of fat calories in the post-exercise beverage. It has often been suggested that adding fat to the post-workout recovery beverage should be avoided because of its potential to slow down the digestion and absorption of ingested carbohydrate (which may suppress the rate of skeletal muscle glycogen resynthesis). The finding of this study indicates that adding fat to the post-workout carbohydrate-protein beverage does not negatively alter the rate of skeletal muscle glycogen resynthesis. In further support of this position, when subjects were given a post-endurance workout beverage containing carbohydrate, protein, and fat (even up to 45% of the calories being derived from fat), it was reported that the added fat content did not alter muscle glycogen resynthesis or glucose tolerance the next day.

Protein/Amino Acids and Muscle Damage

Part of the reason or need for a post-exercise recovery beverage is to suppress muscle damage and decrease DOMS (delayed-onset muscle soreness). Resistance exercise causes micro trauma to muscle fibers in order for the body to repair the damage, returning the muscle to a stronger state.

It really should be no surprise that supplementing resistance exercise with protein/amino acids should be encouraged to elicit muscle repair.

Recovery from a bout of resistance exercise includes replenishing skeletal muscle glycogen, reducing muscle soreness, and attenuating serum markers of muscle damage. Ingesting a carbohydrate-protein beverage after resistance exercise will replenish skeletal muscle glycogen. Also, BCAA supplementation taken in conjunction with resistance exercise has been shown to enhance recovery by suppressing both muscle soreness and damage.

Protein or amino-acid supplementation is often thought of as only being useful to those who resistance train. It should be noted, however, that endurance athletes could also benefit from a sufficient dosing of protein in their diet to maintain current levels of muscle tissue and reduce the catabolic effect chronic cardio plays on their bodies.

Quote of the day:
"I am an optimist. It does not seem too much use being anything else."
~ Winston Churchill