You have probably heard a lot about hormones and how they affect your body, and that is one of the reasons that you exercise the way that you do. But do you really know the difference between the various hormones and what each does?
This series will examine the major hormones of the body, particularly the ones that are influenced by exercise, and show you what impact they can have on your health, appearance and well being.
Insulin-like Growth Factor 1
Insulin-like Growth Factor – 1 (IGF-1)--also known as somatomedin C--is a vitally important and fairly unknown hormone when compared to the other two hormones we have looked at, HGH and Testosterone. While the other two hormones are more well-known, it might actually be IGF-1 that does more of the heavy lifting. If that didn’t get your attention, I don’t know what will.
IGF-1 is produced in the liver in response to the release of HGH into the bloodstream by the anterior pituitary gland. It is known as the “polypeptide protein hormone” because it is made up of over 70 interconnected amino acids in a single chain. Its molecular structure resembles that of insulin (hence the name “insulin-like growth factor”) but it has vastly different functions. Even more so than HGH and testosterone (known as the anabolic hormones), IGF-1 promotes cell division, growth, and regeneration. HGH in the blood stream causes IGF-1 to be released from the liver and many other different cell types all over the body, including your bone cells. It is important for IGF-1 to be released all over the body because its functions are beneficial for all of your cells and it is important for it to be delivered in a timely manner.
IGF-1 helps to increase metabolism in your cells, which leads to growth. It is extremely anabolic in nature, inducing cell division and growth in any type of cell (particularly muscle, bone, skin, the liver, kidney and lungs), as well as your nerves. It helps to stimulate protein synthesis and serves to promote growth in muscle strength and size. IGF-1 serves a very important role in healing as well. This does not only apply for healing wounds, but also to recovering from workouts and other stress or inflammation in the body. While HGH and testosterone are given more credit for promoting growth, it is actually IGF-1 that travels to the cells and directly causes the cell division, growth and regeneration. HGH and testosterone do serve a very significant role, but they should be considered indirect promoters of these effects.
There are many factors that influence your production and levels of IGF-1, which in turn can impact your growth and ability to recover. Nutrition is vitally important to sustaining sufficient levels of IGF-1, and it has been shown that malnutrition can actually inhibit the adequate release of IGF-1 in youth, essentially resulting in stunted growth. Since IGF-1 stimulates protein synthesis, it is important that you are getting an adequate supply of amino acids to provide for the building of muscle protein. It is also absolutely essential that you get enough sleep and quality sleep at the right hours for that matter, to ensure that your body produces enough IGF-1. Since IGF-1 release is regulated by HGH (which is released primarily during sleep), I’m sure you can connect the dots and see how inadequate amounts of sleep can result in a negative feedback and prevent the production of enough IGF-1.
Synthetic products that promote or even provide direct IGF-1 boosts are starting to pop up throughout the industry as people become more aware of the effects and functions of this underrated hormone. But just as well with synthetic or artificially induced HGH and testosterone, this can probably result in detrimental effects. As seen with testosterone, there are negative feedback mechanisms in the body and certain hormones like HGH will stop being produced if there are high levels of IGF-1, synthetic or real. This can be counterproductive and really put things out of whack in your body, interrupting many vital functions. As I stated above, a better way to ensure proper IGF-1 production is to get plenty of sleep, nutrients and protein.
Testosterone and HGH may be the sexy hormones that everyone knows about, but IGF-1 may just be the next wave. People are starting to catch on to the importance of this hormone and the functions it serves in the body, and they are starting to look for ways to promote the production of this as opposed to the other hormones. In general if you are doing the right things and taking care of yourself properly, you should be able to produce enough IGF-1 to reap all the benefits without resorting to supplementing your natural processes. More IGF-1 will mean more muscle, more growth, higher metabolism and faster recovery. So make sure you do the things I outlined above to maximize production.
In the next Hormone Huddle, we’ll examine insulin and how it can either be your best friend or your worst nightmare.
Resources:
Widmaier, Eric; Raff, Hershel; Strang, Kevin. Vander, Sherman & Luciano’s Human Physiology: The Mechanisms of Body Function, Ninth Edition. New York, NY: McGraw Hill, 2004.
"Have You Heard of IGF-1?" IGF1.net. Sytropin. Web. 19 Dec. 2011. <http://www.igf1.net/>.
David Spitz – David is the founder of California Strength Academy in San Ramon. This former high school football player was also a USA Junior National Team thrower in track and field. He is currently working towards his CSCS certification. Clients he has recently trained include Chris Cooper (just resigned with the Oakland Raiders), TJ Ward (second round 2009 / 2010 NFL Draft pick) and Cameron Colvin (former Oregon Ducks and San Francisco 49ers player).