Should You Spike Your Insulin Levels for Maximal Muscle Growth?

The Debate Surrounding Post-Exercise Nutrition

When it comes to post-exercise nutrition, there is a lot of conflicting information surrounding the anabolic window, blood sugar levels, insulin spiking, and eating post-workout carbs. Many articles and bodybuilders claim that you must eat protein with simple carbohydrates like maltodextrin or glucose directly after your workout to maximize muscle growth. This idea is based on the hypothesis that insulin promotes protein synthesis, and therefore maximizing insulin will maximize muscle mass. However, scientific research does not fully support this claim.

The Role of Insulin in Muscle Growth

Insulin is an anabolic hormone produced by the pancreas, which stimulates the uptake of amino acids and protein synthesis in muscle cells. Diabetic patients with high insulin levels have increased muscle mass, while patients with low insulin levels have muscle atrophy. Additionally, patients with type 2 diabetes have a relatively poor insulin sensitivity and insulin resistance, which results in lower muscle mass and quality. Individuals with insulin deficiency can be in a protein catabolic state with loss of muscle mass that can only be reversed by insulin therapy.

Studies on Insulin and Muscle Growth

There have been many studies showing that insulin stimulates protein synthesis, yet there are very few clinical trials showing that elevated insulin levels actually lead to building muscle. To answer the question whether to consume protein or carbohydrates after strength training, a study comparing the effectiveness of protein-only and carbohydrate-only post-workout supplements concluded that protein stimulated more muscle protein synthesis as compared with the intake of carbohydrate only. The consumption of carbohydrates after weight training did increase glucose levels and insulin saturation, but it did not trigger as much muscle growth as the protein-only group.

- Advertisement -

The Effect of Carbohydrates on Muscle Growth

To determine whether it is more beneficial to consume protein or protein with carbohydrates, a randomized controlled trial found that post-workout consumption of carbohydrates with protein did not synergistically or additively improve muscle growth. This study had two groups of men perform single-leg knee extensions. Group 1 ingested 25 grams of protein, while Group 2 ingested 25 grams of protein and 50 grams of the carbohydrate maltodextrin. Both groups demonstrated muscle protein synthesis and inhibition of muscle protein breakdown. However, there was no difference between the groups.

The Importance of Leucine in Muscle Growth

In a study comparing a low-glycemic milk-based supplement and a high-glycemic soy-based supplement, it was found that non-fat milk promoted more muscle protein accretion than soy beverage. This demonstrates that a higher glycemic index associated with blood glucose levels was not positively associated with muscle gains. Another study found that a post-exercise protein supplement stimulated more abdominal fat loss and lean muscle growth than a post-workout supplement with protein and carbohydrates.

Conclusion

Based on the available clinical data, there is no evidence that the addition of carbohydrates to a protein supplement will acutely increase muscle protein synthesis or muscle growth to a greater extent than protein alone. Therefore, if you think the insulin spike from a sugary carb-filled pastry after an intense workout is maximizing your muscle growth, you should rethink that decision.

FAQs

Q: Does insulin promote protein synthesis?
A: Yes, insulin stimulates the uptake of amino acids and protein synthesis in muscle cells.

Q: Does consuming carbohydrates after strength training trigger muscle growth?
A: No, consuming carbohydrates after weight training did not trigger as much muscle growth as the protein-only group.

Q: Is it beneficial to consume protein with carbohydrates after strength training?
A: No, post-workout consumption of carbohydrates with protein did not synergistically or additively improve muscle growth.

Q: What is the best way to maximize muscle growth?
A: Based on the available clinical data, consuming high-quality protein powder like BBCOM’s Signature Whey is the best way to maximize muscle growth, especially if you are focused on a weight loss or fat loss cycle.

Q: Does leucine play a role in muscle growth?
A: Yes, leucine improves bioavailability of the whey protein, resulting in a lower protein oxidation rate. Leucine also increases skeletal muscle Insulin-like Growth Factor 1 (IGF-1) concentration in resistance-trained men.