Anabolic and Catabolic in Weight Training

Woman working out with hand weights
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Weight training seeks to maximize anabolic muscle building and minimize loss of muscle through catabolism. At their most basic, anabolic means "building up" and catabolic means "breaking down." Anabolism and catabolism are the two sides of metabolism—building up and breaking down components to maintain the function of the body and the balance of energy stores.

Anabolism vs. Catabolism

When you hear the word anabolic used in terms such as "anabolic state" and "anabolic steroids," it is referring to the muscle-building processes and the hormones that promote them. Likewise, when you hear the word catabolic, it will mean processes that lead to losing the muscles you work hard to build.

Anabolism
  • Builds and maintains muscle

  • Requires energy

  • Builds large molecules from small, simple molecules

  • Hormones involved include growth hormone, IGF1 (insulin growth factor), insulin, testosterone, and estrogen

  • Types of anabolic exercise include weight training

Catabolism
  • Breaks down muscle (glycogen) and fat

  • Releases energy

  • Breaks down large molecules into small, simple molecules

  • Hormones involved include cortisol, glucagon, adrenaline, and other catecholamines

  • Types of catabolic exercise include cardio

Anabolic Processes

Anabolic metabolism (anabolism) builds new compounds and tissues, including muscle. The body uses building blocks such as proteins and amino acids in this process and burns energy to do it. In weight training, anabolic metabolism builds and strengthens muscles and bones.

Hormones are produced naturally in the body to regulate metabolism, including the use and storage of energy and building of muscle and other tissue. Anabolic hormones include:

  • Estrogen
  • Growth hormone
  • IGF1 (insulin growth factor)
  • Insulin
  • Testosterone

Catabolic Processes

Catabolic metabolism (catabolism) breaks down complex compounds and body tissues. This process releases energy. The body uses catabolism when energy is needed. Sustained high-intensity exercise, such as running a marathon, can result in the catabolism of muscle as the body turns to breaking down protein for energy when glycogen stores are depleted.

Exercising hard for a long period of time without replacing energy with food and drink can lead to the breaking down of muscle for fuel.

Catabolic hormones include:

  • Adrenaline
  • Catecholamines
  • Cortisol
  • Glucagon

These hormones may not affect all tissues the same; for instance, they can have catabolic effects in making energy available, but not break down muscle.

Anabolic Steroids

Anabolic steroids are natural or synthetic drugs that mimic the effects of testosterone, the male sex hormone. Anabolic steroids are banned in sports because because of their negative side effects and the fact that they provide the user with an unfair advantage. It is illegal to possess, use, or distribute steroids without a prescription and medical supervision.

As they are prescription drugs, anabolic steroids are illegal to obtain and use without a medical need. Anabolic steroids have unpleasant and dangerous side effects, which is why they are only available by prescription and require medical supervision.

Anabolic steroids are used to build more muscle in a shorter period of time. Some legal dietary supplements, such as DHEA, are building blocks of steroid hormones and might be taken in an attempt to build muscle artificially. Bodybuilders who engage in "natural bodybuilding" aim to keep their anabolic hormones high and catabolic hormones low, but don't use prohibited drugs to promote muscle growth.

Whereas anabolic steroids are very clearly banned, there is a gray area when it comes to a supplement called prohormones. Prohormones are compounds that are sometimes added to supplements that turn into anabolic hormones in the body and promote muscle growth.

However, these muscle-building effects are usually short-term and prohormones are banned by some athletic associations. You also have to be careful about purchasing any supplement that doesn't have any third-party evaluation. The FDA doesn't regulate supplements and prohormones may be found in your supplements without them being listed in the product's ingredient list. 

Maintaining an Anabolic State

Weight trainers generally aim to exercise while in an anabolic state. Maintaining an anabolic state will ensure they have enough nutrients in their system to fuel their workout and provide the building blocks of protein for muscle growth.

Nutrient timing has been shown to maximize anabolic processes such as muscle building. Specifically, eating protein every three hours throughout the day is emphasized by the International Society of Sports Nutrition (ISSN). Many weight trainers follow pre-workout nutrition regimens to optimize their bodies for building muscle. Before exercising, eating foods rich in carbohydrates and protein or protein alone helps increase strength and muscle mass.

People who weight train may also aim to take in food and drink that will provide enough nutrients to maintain an anabolic state both during and after their workouts. During weight training, the ISSN recommends consuming carbohydrates, with or without protein. Within two hours after exercising, eating high-quality protein helps stimulate muscle protein synthesis.

Weight trainers also design workouts to challenge their muscles, so the body responds by building more muscle. Weight training and resistance workouts that target different muscle groups are particularly effective. Maximizing rest and recovery between workouts can also improve strength and endurance.

Getting adequate sleep is another important component of the anabolic state, allowing the body to build and repair muscle more effectively.

Anabolic Products

You may see nutritional products and supplements labeled as either anabolic or anti-catabolic. Anabolic products provide carbohydrates, proteins, and amino acids that they claim will be absorbed quickly and available to the muscles to build more muscles.

Tribulus (Tribulus terrestris) is a dietary supplement that claims to have anabolic effects by increasing testosterone levels and muscle mass. However, these claims are mostly unsubstantiated.

Anti-Catabolic Products

Anti-catabolic labels, on the other hand, might be added to food and supplements that take longer to digest, so they provide the needed nutrients over a longer period of time. Anti-catabolic products slow down the breakdown of muscle. Creatine, for example, has an anti-catabolic effect on the body and helps protect against muscle protein catabolism.

Hydroxymethylbutyrate (HMB) also has anti-catabolic effects and is often marketed as a performance-enhancing supplement. A 2017 review of nine studies showed that daily intake of 3 grams of HMB in combination with resistance training reduced muscle damage, stimulated muscle growth, improved strength, and improved power. Although promising, more studies need to be done to verify these outcomes.

Frequently Asked Questions

How can you remember the difference between anabolic and catabolic processes?

When it comes to anabolic processes, think of building. With catabolic processes, on the other hand, it's all about breaking down. Anabolic processes require energy to build large, complex molecules from small, simple molecules to help build and maintain muscle. Catabolic processes release energy as they break down large, complex molecules into small molecules, and break down muscle and fat.

What is metabolism?

Metabolism refers to the continuous processes that your body uses to sustain life by converting food into energy. Some examples of these processes include breathing, circulating blood, digesting food, and building and repairing muscles and tissues.

What is activation energy?

Activation energy is the minimum amount of energy required to make a chemical reaction occur. Think of it as the extra little push you need to get started on a task or exercise.

A Word From Verywell

Anabolism and catabolism work together as part of very important metabolic processes. However, weight lifters often focus on building up their anabolic hormones to stimulate muscle growth. There are many anabolic and anti-catabolic supplement products available, but some are banned by athletic associations. Consult with your physician before taking any new weight training supplements. A balance of anabolic and catabolic exercise as well as proper nutrition may be the best way to maintain health.

9 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Paul Rogers
Paul Rogers is a personal trainer with experience in a wide range of sports, including track, triathlon, marathon, hockey, tennis, and baseball.