I may have mentioned this before, but I’ll say it again; our body is a finely tuned machine.
Its capacity to perform incredible physical tasks is limited only by our commitment or desire to input the right fuel, and subject it to the appropriate stressors (in order for it to adapt and for us to increase our potential to reach our own version of physical perfection). Obviously within genetic constraints, e.g. you can’t change your height through training.
What many people are confused about are the hormonal reactions that can influence any change. We need to learn more about the how hormones impact on our body, so we can work with them to achieve this optimal state rather than against them.
A commonly talked about hormone that affects our system is insulin. Insulin is secreted as a reaction to a sudden spike in blood sugar, such as when we eat certain foods, (yep, lollies, but also surprisingly jasmine rice) in order to bring blood sugars back down to a normal level.
When our nutritional habits lead to this being a constant action, insulin insensitivity results and more sugar stays in the blood than can be physically taken up by the muscles. We readily hear about insulin insensitivity being a precursor to diabetes and how what we eat can create this anomaly.
Current research implies that resistance/weight training can increase insulin receptors on muscle tissue and may help in reversing insulin insensitivity – which is yet another reason why women should do weights above all else.
Other hormonal contributors to health and body composition include growth hormone, endorphins, glucagon and cortisol.
Growth hormone, released from the anterior pituitary gland promotes protein synthesis and so helps cells and tissues to repair and grow, which is also why GH is used illegally by athletes wanting to speed things up. GH stimulates gluconeogenesis in the liver (the creation of glycogen for energy) and also stimulates lipolysis (the breakdown of fat for fuel) effectively mobilising fuels that the muscles can use for energy to exercise.
This is one of the basic physiological reasons why if performed at the right level of intensity and duration for the individual, regular exercise decreases excess body fat stores.
Endorphins are the ‘happy hormones’. Without getting overcomplicated and scientific and because you will have heard of them, these are a by-product of adequately intense exercise. These are also secreted in response to the consumption of chocolate. No surprises there.
Glucagon is basically the opposite of insulin. Glucagon is secreted when the blood sugar is too low in order to normalise blood sugar levels, and this can occur during exercise as we use up glycogen stores and blood sugars and require more energy.
Glucagon stimulates liver glycogenolysis (the production of glycogen) to raise blood glucose concentration and again stimulates lipolysis from adipose tissue (fat stores). Glucagon stimulates the burning of body fat stores and insulin inhibits it; i.e. exercise sparks off glucagon and eating a slab of chocolate cake secretes insulin.
Cortisol is the ‘stress’ hormone. It is released from the adrenal cortex in the brain that increases the uptake and conversion of glucose from liver in the presence of adrenalin (which is stimulated by exercise). The trick here, and why so many women struggle to lose weight, is that too much cortisol in the system actually inhibits fat lipolysis. Another reason why performing just the right amount and level of exercise for the individual and reducing environmental stressors like traffic jams, work overload and late nights has always been a good idea.
During brief periods of light to moderate exercise, energy is derived in equal amounts from carbohydrate (sugars) and fat. Exercise increases the blood plasma concentrations of lipogenic hormones: adrenaline, glucagon, cortisol and growth hormone (the ones that stimulate the use of fat stores for energy) so that muscles receive a constant supply of energy-rich FFA and insulin is suppressed. So more good news then. And the even better news it that this process does not cease immediately after exercise has stopped.
The main thing that can be taken from all this is that exercise positively stimulates the secretion of hormones that help us to burn body fat stores for fuel, but only if performed at the right level for the individual so as not to cause overstress, and for a long enough duration to create the hormonal response needed to convert fatty acids for energy.
You probably already knew that three minutes a day didn’t really work and now you know why.