“Eat some candy after your workout, you need to keep those insulin levels high bro, that’s how you get jacked”. No “bro”, it isn’t.
Insulin is a hormone that tells your body’s cells to use the sugar in your blood. It is a so called “anabolic” hormone, which many people have interpreted to mean “muscle building”.
The word anabolic, however, doesn’t mean building muscle. It means building large molecules from smaller ones. In this case insulin helps your body take small glucose molecules from your blood and store them in your cells as larger sugar molecules called glycogen.
Insulin DOES play a role in muscle building though, but it works mainly by limiting muscle breakdown, rather then helping muscle buildup [1]. However, VERY low levels of insulin are needed to get these benefits [2, 3]. In fact, eating your protein will stimulate insulin levels enough to stop muscle breakdown [4, 5], and adding carbs for a “bigger” insulin response won’t do any good.
So stop chasing high insulin levels to build muscle. Instead start chasing maximal volume at heavy enough loads, proper protein intake and enough recovery.
THE EVIDENCE:
1. Abdulla et al. Role of insulin in the regulation of human skeletal muscle protein synthesis and breakdown: a systematic review and meta-analysis. Diabetologia. 2016;59(1):44–55. doi: 10.1007/s00125-015-3751-0.
2. Greenhaff et al. Disassociation between the effects of amino acids and insulin on signaling, ubiquitin ligases, and protein turnover in human muscle. Am J Physiol Endocrinol Metab. 2008;295(3):E595–E604. doi: 10.1152/ajpendo.90411.2008.
3. Rennie et al.Branched-chain amino acids as fuels and anabolic signals in human muscle. J Nutr. 2006;136(1 Suppl):264S–268S. doi: 10.1093/jn/136.1.264S.
4. Power et al. Human insulinotropic response to oral ingestion of native and hydrolysed whey protein. Amino Acids. 2009;37(2):333–339. doi: 10.1007/s00726-008-0156-0.
5. http://www.ncbi.nlm.nih.gov/pubmed/26556791