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4 Hormones That Influence Muscle Growth

It’s easy to take our hormones for granted until they stop performing as they should. A healthy hormone system enables us to stay in shape and conduct our daily activities, but it’s even more important to those trying to gain muscle.
It can be frustrating to dedicate a lot of time and effort to your physique and not see the desired results, yet hormones are rarely thought to be the culprit. With diet and training taking center stage, hormones become an overlooked factor in muscle growth. Here we take a look at the five key hormones that power our muscles and how you can adapt your training techniques for a better outcome.
How do hormones affect muscle growth?
Hormones are vital in regulating our metabolism – the reaction that governs our energy and processes our food intake. During and after a workout, your body is flooded by different hormones which are either anabolic (those that use energy) or catabolic (those that release energy). Only the muscles stimulated during this exercise are subject to the effects of these hormones.
For muscle growth, you need a higher amount of anabolic hormones than catabolic ones. Hormones required for muscle growth include:
- Insulin;
- Insulin-like growth factors (IGFs);
- Growth hormone (GH);
- Testosterone.
Anabolism enables our muscles to grow because the process involves simple molecules forming together into larger, more complex ones and retaining energy for repairs.
Catabolic hormones, such as cortisol, inhibit muscle growth as the process breaks down molecules and releases energy, for example, food digestion. If there is a higher imbalance of catabolic hormones, you will begin to lose muscle mass.
Any hormonal disruptions, for example, those caused by a thyroid condition, will affect these processes and your overall metabolism. If you’re concerned about a hormone imbalance, or curious about what your baseline levels are, our clinic provides a free consultation you can book right away.
Key Anabolic Hormones
When creating a training plan, it’s important to bear in mind that hormones affect muscle growth and strength differently. For bodybuilding, your anabolic hormones play a critical role by stimulating muscle growth. Other hormones, such as cortisol, epinephrine, norepinephrine, and glucagon, increase the availability of glucose (your body’s source of fuel) and aid strength training.
Testosterone
This male hormone is primarily produced by the testicles, and by the ovaries in women, albeit in lower quantities. Testosterone regulates muscle mass, strength, fat distribution, libido, and bone mass; making it one of the most important hormones for bodybuilding. Classed as an anabolic hormone, testosterone increases neurotransmitters in the nervous system to enhance muscle size.
Using testosterone supplements is rather popular amongst bodybuilders but has been banned in sports competitions as it comes with many potential health risks. Today, testosterone therapy is allowed for men with officially diagnosed hypogonadism (low T) in their blood.
Growth Hormone
Growth hormone supports the development of skeletal muscle tissue, body strength, and eliminating body fat. GH production declines with age, which means the less GH you produce, the more body fat you will accumulate. Your body releases GH during its REM cycles of sleep and uses this time to repair any damaged muscle cells. Improving your quality of sleep will, in turn, help your workout efforts.
Exercise also releases growth hormone, particularly in compound movements that use multiple joints, for example, squats or bench presses. The more muscle fibers you are using, the more GH your body will create.
Insulin
Insulin is responsible for storing the product of food breakdowns in the muscles and liver. As another anabolic hormone, it moves amino acids into your muscle cells to help repair tissue. Insulin can have positive impacts on your muscles but could also become a burden if you have excess body fat. The production of insulin is heavily influenced by diet and exercise, so it can be something that you control.
However, you may not know that training can increase your body’s sensitivity to insulin, which is why it’s always so hard to lose the last bit of fat. Once you’ve lost some weight, your body shifts into survival mode and tries to protect the remaining fat and muscle it needs to function. To combat this, try eating healthy fats that insulin is less sensitive to, for example, fish, nuts, coconut oil, etc.
Insulin-Like Growth Factors (IGFs)
This hormone is produced in the liver in response to the growth hormones, so if GH levels rise, as do IGFs. As the name suggests, IGFs stimulate muscle growth as well as increasing lean body mass, helping you burn fat, increasing your physical endurance, and accelerating your recovery time. Your IGF levels peak during puberty and gradually decrease with age.
Cortisol: Catabolic Hormone Role
Cortisol is a catabolic hormone triggered by physical and emotional stress. It breaks down your muscles when your blood sugar is low, so those of you that enjoy endurance sports may have experienced its effects. By breaking down the tissue, cortisol can prevent muscle gain, making it clear why minimizing your cortisol levels is beneficial for bodybuilders.
To summarise, you should try to minimize your catabolic hormone release by keeping the duration of your workouts shorter and making sure you are not excessively stressing your muscles.
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