ENDOCRINE SYSTEM RESPONSES
Most of us don’t realize the role that the Endocrine System plays on regulating our body processes. As we age, there is a decrease in our fat-burning hormones and an increase of our fat-storing hormones. I can relate the body’s regulatory processor (i.e., the endocrine system), as a case of “it’s not me, it’s you!”
Indeed we are not in control of the changes that naturally happen in our hormonal control center. We tend to blame ourselves, or accept these changes as the natural developments with aging.
But we don’t have to! I say we fight this system that expects us to surrender and become a shadow of what we once were! I want to keep my energy level, my waistline, and my emotional balance; and I hope you will want to do the same.
GROWTH HORMONE:
Growth hormone is involved in building lean tissue and burning fat. As it declines, along with testosterone, we tend to pack on fat which lowers these hormones even more, and starts the cycle of weight gain.
The Role of Growth Hormone:
- Enhances protein synthesis (builds muscle)
- Increases utilization of fatty acids (burns fat)
- Builds collagen (youthful skin)
- Enhances immune function (keeps you healthy)
- Stimulates cartilage growth (increased bone density)
CORTISOL:
The main job of Cortisol is to regulate our metabolism. It does this by increasing available fuels when there is a shortage or when more fuel is needed for quick energy (like when you are being chased by a dog).
Cortisol is secreted when glycogen concentrations in the muscles are low by:
- Stimulating the production of new glucose in the liver
- Inhibiting the action of insulin, preventing glucose uptake into the muscle and increasing blood glucose levels
- Increasing protein breakdown in the muscle and fat in the adipose tissue; (both processes deplete stored energy and release fuel into the bloodstream for quick use)
Cortisol Increases with Stress & Age:
Cortisol increases with stress and age and leads to increased abdominal fat.
The effects of increased cortisol include:
- Slower metabolism (we burn less calories)
- Reduced lean tissue (we lose muscle)
- Loss of energy (we become lethargic)
Cortisol’s Benefits:
- Regulates the sleep-wake cycle
- Potent anti-inflammatory agent (athletes use it to treat injuries)
- Regulates blood pressure by stimulating vessel constriction
Cortisol’s Negative Effects:
- Cortisol has an immunosuppressive effect (making us susceptible to illness or infection)
- Decreases bone density (inhibiting bone formation and decreasing intestinal calcium absorption)
- Inhibits sex hormones (decreased libido/difficulty conceiving)
Cortisol & Exercise:
As with growth hormone, cortisol increases with resistance exercise, especially when rest periods are short and total volume is high.
Because cortisol is released in response to stress, exercise training will increase the threshold of cortisol release (meaning the more physically fit you are, the less cortisol is released).
- If you exercise for more than 60 minutes, even at a low intensity, the body’s glycogen stores (fuel) will decrease significantly and the increased stress will cause more cortisol release
- The more training you do, the better your body will become at dealing with physical stresses and decrease the need to release cortisol
This effect is not limited to exercise; people who are regularly active show a decreased cortisol response to an emotional crisis when compared to sedentary controls.
SEX HORMONES:
Estrogen
As women age their estrogen levels decline. At menopause, their hormone levels plunge as their ovaries produce less estrogen, progesterone, and testosterone leading to more unhealthy visceral fat in their bellies.
The Effect of Lower Estrogen Levels:
- Increased appetite
- Reduced fat burning
- Redistribution of fat to the belly area
- Decreased energy
- Fat becomes the dominant source of estrogen
- Levels of cortisol rise; raising blood pressure and blood sugar
Progesterone
Progesterone also declines with age, altering the progesterone-to-estrogen ratio and causing a condition known as “estrogen dominance.”
This can lead to:
- Irritability
- Depression
- Sleep problems
- Water retention
- Increased appetite
- Sugar cravings
Testosterone
Testosterone is important for weight management because it helps build and maintain muscle. It also burns fat and increases energy.
As testosterone declines with age, the result is:
- Loss of lean tissue and muscle tone
- Lower mental energy
- Increased visceral fat
The loss of lean tissue and muscle tone slows your metabolism even more, since muscle burns more calories than fat.
The Benefits of Exercise:
Exercise is a good way to activate hormones and counter cortisol’s effect on our waistline.
- Exercising at least 3 times per week for 45 minutes can increase secretion of hormones
- With increased activity, natural hormone levels start to increase
- Exercise builds lean body mass; which burns more calories and directs calories to our growing muscles and away from our fat cells
Exercise promotes the release of adiponectin, growth hormone, adrenaline, and testosterone; all hormones that enable fat to be used.