Exercise may temporarily decrease appetite by altering appetite-regulating hormones such as ghrelin and increasing satiety hormones such as peptide YY and glucagon-like peptide 1. Exercise also produces other benefits, including reductions in inflammation-inducing cortisol, which in turn triggers more satiety hormones such as peptide YY and glucagon-like peptide 1.
Regular exercise can help regulate hormones and maintain a balanced hormonal state. In this article we’ll look at both muscle strengthening and aerobic (endurance) exercise’s impact on specific hormones.
Estrogen
Hormones are substances produced by one tissue that travel throughout the body via bodily fluid to influence another tissue or group of tissues. Estrogen is an essential sex hormone made in women’s ovaries, adrenal glands and body fat; pregnancy also gives us additional sources. Estrogen works its magic in our bodies by binding to proteins known as estrogen receptors which then react accordingly.
Cortisol, a stress hormone, can disrupt the delicate balance between estrogen and testosterone levels in your body. Exercise-particularly cardiovascular conditioning and strength training-can reduce cortisol levels and support more balanced levels of both.
Regular exercise also boosts human growth hormone (HGH), helping maintain muscle mass and bone density. Women going through menopause should prioritize physical activity to increase HGH production to counteract any loss in muscle and bone density from low oestrogen levels.
Testosterone
Testosterone, a male sexual hormone, plays an integral part in puberty’s reproductive organ development as well as adult sperm production and muscle, bone and blood cell formation. Furthermore, its increased levels promote increased sexual behavior among both genders. Testosterone derives its substance from cholesterol.
Studies have revealed that different forms of exercise affect our bodies differently in terms of hormonal responses. In general, endurance exercise increases levels of fibroblast growth factor 21, while resistance training with weights lowers it.
Anabolic hormones like testosterone, the GH superfamily hormones insulin and IGF-1 tend to rise dramatically during and for 30 minutes following resistance exercise, providing adequate mechanical stimulation. Resistance training protocols with high volume/moderate-intensity/short rest intervals typically result in greater acute hormonal spikes.
Growth Hormone
Researchers have discovered that muscle contraction releases myokines, hormones which support tissue repair and growth, lower glucose levels in the blood, increase insulin sensitivity, and decrease inflammation. Exercise also regulates menstrual cycles and allows us to use fat as energy sources.
Growth hormone is released intermittently during sleep, low glucose levels and stressful situations, with its release being controlled by both the hypothalamus (part of the brain) and pituitary gland – stimulated by growth hormone-releasing hormone stimulation while inhibited by somatostatin inhibition.
An excess of growth hormone can have serious repercussions, including bone and tissue enlargement and increased blood pressure. This condition is most commonly caused by benign pituitary tumors but could also occur as the side effect of drugs designed to stimulate growth hormone production, such as steroids.
Insulin
Insulin is produced in the pancreas’ islets of Langerhans. Insulin helps cells use glucose as energy and maintain normal blood sugar levels while also playing an integral role in controlling fat and protein breakdown.
Insulin binding to its receptors sets off several intracellular signaling pathways, including translocation of GLUT-4 storage vesicles to the cell membrane for glucose absorption; glycogen synthesis; and glycolysis as an essential step in fuel utilization by cells. Insulin also inhibits triglyceride and cholesterol synthesis.
Exercise, especially resistance training with weights, increases the release of HGH. This hormone promotes muscle growth, tissue repair, healthy sleep patterns and metabolism while simultaneously increasing fat loss and decreasing muscle wasting. Furthermore, HGH promotes anabolic hormones such as testosterone and growth hormone which explains why regular resistance exercises produce optimal body composition changes; however researchers have discovered that different forms of exercise such as cardio or strength training impact HGH differently.