Human Growth Hormone (HGH) is a naturally occurring hormone secreted by the pituitary gland. HGH is released in short bursts every three to five hours and dissipates rapidly with the highest levels occurring about an hour after falling asleep. HGH, often referred to as the ‘fitness hormone’ plays a major role in regulating our metabolism, enhancing our recovery abilities, building muscle and strength, and providing vitality and energy.
As we reach our 30's and beyond, we enter into the 'somatopause' where our HGH levels start to fall off and gradually decrease more as we get older. This decrease in HGH is partly responsible for the aging process as well as a reduction in lean body mass and strength and an increase in bodyfat, aka, the 'middle aged spread'. Indeed, many of the problems of aging are attributable to the decline in HGH and the resulting loss of lean muscle tissue. This all sounds a bit depressing doesn't it, so that is why it is important to do what we can, naturally, to maintain our levels of HGH as we get older, without resorting to expensive or illegal injections. We can test our levels of HGH and the easiest and most accurate way is to have an IGF-1 blood test. IGF-1 is a hormone produced in response to HGH secretion and if IGF are below a certain threshold, this is indicative of a HGH deficiency. So how do we stop this decline of HGH and even increase it? Well, its good news folks in that we can naturally increase our HGH levels. In fact, a number of physiological stimuli can initiate HGH secretion, with the most powerful being exercise and sleep. Yep. A good night’s sleep is critical to secretion of HGH but in this article, we'll focus on exercise.
The key to producing more HGH with exercise is to train the fast muscle fibres, particularly the superfast Type IIx muscle fibres through short burst, high intensity training. We use more fast twitch muscle fibres for anaerobic exercise such as lifting weights, sprinting, high intensity interval training. These muscle fibres are more efficient in generating short bursts of strength or speed, however, they fatigue more quickly. They get their name because they fire very rapidly.
Short burst or interval training means exercising intensely for a short period, 30 to 60 seconds for example, and then resting for 1 – 2 minutes. Basically, we are alternating between high and low intensity exercise or rest over a 20 – 30 minute period. There are a number of variations of this type of training with names such as burst cardio, high intensity interval training, peak fitness and so on. They are all based on the same idea of short intense bursts of exercise, followed by a short rest or lower intensity exercise.
Here is one variation of this type of training. The objective is to elevate the heart rate to anaerobic thresholds for 30 seconds and recover for 90 seconds. This cycle is repeated 8 times. You'll need a couple of minutes to warm up preceeding the exercise and a few minutes to cool down afterward. The exercise could be on a treadmill, elliptical trainer, or recumbent bike for example. The intensity is dependant on the individual and for those starting out, it could simply be alternating fast walking with slow walking. The important thing is to elevate the heart rate into the training zone for 30 seconds and then rest. You might think that 30 seconds is not very long but if you are working hard enough, it will be enough.
Think of the 100 metre sprint. Olympic athletes can run the 100 metres in less than 10 seconds these days. This is extreme high intensity. These athletes spend all their time training for these 10 seconds so all of their training is very high intensity in short bursts. However, you don't need to be an Olympic athlete to apply the principles of short burst/interval training.
It can be tailored to any starting level of fitness so if you are very fit, you might be sprinting at the track for example. If you are just starting out, then you could be out in the countryside walking. It really doesn't matter as the benefits are the same and your fitness will increase along with your HGH levels! These workouts are much shorter than traditional hour long cardio sessions and much more effective. In total they last 20 minutes and in that time you will have done only 4 minutes of intense exercise. However, you will certainly feel like you have worked hard, therefore, break into this routine gradually as you don't want to overdo it when you first start out.
Sports & fitness nutritionist, researcher and author on a mission to improve the human condition. Focusing on evidence-based and outcome-based nutrition, training, mindset & environment