Hormones in Training

Like all topics in exercise science, studies conflict with each other on how training affects hormones. While your choices will affect them in the short run, there is no major long-term difference. We also lack enough certainty on how to change them to use hormones as a gauge for a good program. Beyond drugs that alter the body’s chemistry at all times while used, trainees have only a negligible ability to affect them.


Quite frankly, the research shows almost anything you want to see, and the opposite, and a number of results somewhere between.

– Arthur Jones

Although research can help us, remember that exercise scientists are people that make mistakes and have opinions just like in any other field. The basic research on physiology and biomechanics is rather concrete. The more applied the research becomes, such as recommending Olympic lifting programs for everyone, the less likely it will give us a sure answer.

Greater concentrations could show a temporary response to muscle damage, or increase and decrease due to other factors unrelated to training. Throughout our daily lives, a could harm us, and hormones can change due to unknown reasons.

For example, diurnal variations, or fluctuations in hormone levels throughout the day, can affect the magnitude or direction of the hormonal response beyond training and can seem random.

Main Hormones

Several hormones have received attention due to their relationship with muscle size and strength. Others exist but these have the most effect:

  • Testosterone increases protein synthesis. It has many effects beyond muscle growth though. It promotes general tissue growth and maintains cardiovascular health. It matures the male sex organs and can lead to androgenic effects that increase body hair, male pattern baldness, libido, skin oils, and aggressive behavior.
  • Growth hormone mobilizes fatty acids for energy. It can increase protein synthesis, increase amino acid transport, and develop bones. It can spare glucose and amino acids as energy sources, promote collagen synthesis, and support cartilage growth.
  • Insulin-like growth factors (IGFs) increase the protein synthesis of our cells. They stimulate myoblast proliferation, suppress proteolysis, and increase glucose along with amino acid uptake.

All these work by allowing the body to grow muscle. Drugs work by increasing concentrations of these hormones or allowing for more receptors at all times. They give very powerful advantages.

These hormones can vary in concentrations based on the factors of an exercise program. Many feel that more sets and exercises, moderate reps, and short rest periods associated with the pumplactic acid buildup and bodybuilding may do more to stimulate these hormones. Offsetting this, less work reduces cortisol and other hormones that rise from stress and can break down tissue.

Studies have shown each one increasing, decreasing, or remaining the same despite similar programs though. Concentrations at rest can show little or no chronic change and the effect may only occur during and right after training. If an effect occurs, perhaps it may boost growth in the short run but have the same result when viewed over more time, such as a few days.

Ignore Hormones

Drugs will increase hormone levels on a long-term basis and add much more muscle beyond any doubt. With natural trainees though, fluctuations seem to matter little or not at all.

I would suggest ignoring the effects that hormones have on training. Instead, monitor your lifting progress, which summarizes the complexity anyway. Are you adding weight to your lifts over time?

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