An increase in protein synthesis and a decrease in protein breakdown is the first step in muscle growth. Our hormones are directly involved with both protein synthesis and breakdown and play a major role. The hormonal system supports normal function of the body and helps it respond to external stimulation as heavy resistance training. Hormones are chemical messengers that are made, stored and then released into the blood by different endocrine glands, such as pituitary, thyroid, adrenal etc.
The main goal of any serious resistance training is to promote tissue growth by increasing the amount of anabolic hormones released into the body including the big 3: testosterone, growth hormone and insulin or IGF (Insulin-Like Growth Factors). On the other hand catabolic hormones (cortisol and progesterone) are the enemy of resistance training since they contribute to the breakdown of muscle protein, to be used for glucose (energy) synthesis.
TESTOSTERONE
Testosterone is the primary hormone that interacts with skeletal muscle tissue. Most research has been undertaken on male subjects and although there are variations between the different genders, similar training protocols can be followed, even though women have 15-20 times lower testosterone concentrations than men. To increase testosterone levels, the following guidelines should be considered when designing your training program:
Testosterone levels are typically highest in the morning and drop with time during the day. This makes gains in the morning easier, but if you train in the afternoon your total testosterone levels will be higher throughout the entire day, since resistance training according to the below guidelines actually increase testosterone output.
Undertake training using predominantly large-muscle group exercises such as squats, deadlifts, pull-ups/chins, etc
Perform high intensity, heavy resistance or combine high volume, multiple sets of an exercise with short rest periods (30sec-1min).
GROWTH HORMONE (Anabolic)
Growth Hormone (GH) also known as somatotropin is naturally secreted by the pituitary gland. GH is vital in the normal development of children, but it is also a major link in adapting muscles to resistance training. There are many synthetic GH supplements on the market today and some do hold some value, however exercise-induced GH secretion is very different from GH injections. The hypertrophy (muscle building) seen from exercise induced GH shows a much higher force production (ability to lift heavier weight) than synthetic GH.
The major physiological uses of Growth Hormone are:
decreased use of glucose and an increased use fat breakdown (lipolysis)
increased protein synthesis and enhanced immune function
increased use of fats
The largest increases in GH levels are seen when following simple guidelines:
10 repetitions at heavy resistance
3 sets of each exercise
1 min rest intervals
Consume both carbohydrates and protein before and after workouts.
INSULIN-LIKE GROWTH FACTORS, IGFs (Anabolic)
Many of the GH effects are transported through IGFs. IGF-1 is the primary IGF involved with respect to exercise. IGF has a major role in protein synthesis. Responses of IGF-1 to heavy resistance training, however, remain unclear and are currently being investigated by researchers worldwide.
EPINEPHRINE (Anabolic)
Epinephrine is a catecholamine that is secreted by the adrenal medulla and is important in strength and power activities. It is usually one of the first endocrine functions to occur in response to resistance exercise. This hormone acts as the central motor stimulator, peripheral vascular dilator, and enhances enzyme system in muscle.
Some of the physiological functions of epinephrine include:
increased muscle contraction rate
increased Blood Pressure
increased energy availability
increased blood flow
augments the secretion rates of other hormones, such as testosterone.
Heavy resistance training has been shown to increase epinephrine levels during maximum exercise.
CORTISOL (Catabolic)
Cortisol is an enemy number one in high intensity training, and therefore needs to be avoided. Cortisol also plays a role in suppressing the immune system, which has a negative effect on the recovery and remodeling of muscle. The reason is that cortisol is an extremely catabolic hormone that helps convert amino acids to carbohydrates when glycogen levels in the muscle are low. It is vitally important for survival circumstances, but for resistance training it limits muscle protein synthesis and therefore muscle growth. The major problem with limiting cortisol is that the same resistance training protocols, short rest periods and high training volume, that promote GH release, also increases cortisol.
To reduce the release of cortisol a quality diet of carbohydrates and protein before and after each workout is essential to help promote testosterone, GH, IGF and Epinephrine levels. Always remember to vary workout routine in order to prevent the chronic catabolic responses that can occur when too much cortisol is released, often in an overtraining state.
Aging effects in men
Aging in men is marked by a progressive reduction in the daily production of GH as well as testosterone. The hyposomatotropism of aging is associated with increased fatigue, decreased physical performance, reduced lean body mass, and an accumulation of abdominal visceral fat mass. Testosterone bioavailability falls in parallel, such that its production is reduced by nearly one third by age 70 and one half by age 80. Hypogonadal-like features may emerge concurrently in the aging male, e.g. loss of bone and muscle mass, diminished libido and potency, impaired psychological well-being, and variable reduction in red cell mass.
Recent studies of Growth Hormone or Testosterone supplementation indicate that important anabolic effects can be elicited in GH-deficient, hypogonadal, and healthy older men, such as enhanced lean body mass, greater strength and muscle protein synthesis, increased bone mineral content, and an improved sense of well-being. However, higher doses of androgen may cause polycythemia, diminish plasma high density lipoprotein (HDL) concentrations, worsen sleep apnea, and stimulate prostate growth. Likewise, GH supplementation may induce peripheral edema, arthralgias, carpal tunnel syndrome, gynecomastia, and mild glucose intolerance. One approach to addressing the foregoing concerns would be to limit the amounts of Testosterone or Growth Hormone administered.
Summary
A short-term combined administration of Growth Hormone and Testosterone in older men elevates serum concentrations, improves selected facets of physical performance, and increases muscle IGF-I gene expression without measurably changing body composition or muscle strength or inducing clinically adverse events. These preliminary outcomes suggest the utility of evaluating the impact and safety of longer-term, midphysiological bihormonal supplementation in older men.
