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Table of Contents

Magill’s Medical Guide, 9th Edition

Strength training

by Bradley R. A. Wilson, , PhD

Category: Procedure

Anatomy or system affected: Musculoskeletal

Specialties and related fields: Physiology, fitness, gerontology

Definition: Strength training is a type of physical exercise specializing in the use of resistance to induce muscular contraction which builds the strength, anaerobic endurance, and size of skeletal muscles

Key terms:

anabolism: the repair/growth stage of muscle development

body weight: the use of the person’s natural weight as the form of resistance while exercising

catabolism: damage to muscles

free weight: a freestanding object whose weight is used as resistance while exercising

stretchable tubing: elastic workout object with little to no weight that uses tension to create resistance for exercise

spotter: a person who assists with a person exercising to ensure proper technique and injury prevention; this can hands-on, by being in a physical position to prevent accidents, or hands-off by watching the exercising person and being ready to assist as needed

weight machine: a stationary machine used for exercise that uses attached weights and gravity to offer resistance

INTRODUCTION

Strength training, also called “resistance training” or weight lifting, is a type of exercise that uses resistance to build strength, muscle mass, and endurance. Resistance may be in the form of weights, weight machines, stretchable tubing, or body weight. Using resistance causes muscles to contract, or shorten, which strengthens them.

When a person creates resistance on a muscle, tiny tears damage the muscle cells. After strength training, hormones, nutrients, and proteins in the body repair and replenish muscles, helping them to grow. The damage to the muscles is called “catabolism,” and the repair/growth stage is called “anabolism.” Building muscle has many positive health effects. It has been shown to help people manage their weight, strengthen their bones, and build up their stamina.

TYPES OF STRENGTH-TRAINING EXERCISES

Fitness experts group strength-training exercises by the type of resistance used. These exercises can be performed by using free weights or items found in the home, specialized machines found at gyms, resistance tubing, or even one’s own body weight. People can use a combination of different strength-training exercises along with cardiovascular exercise to achieve maximum health and performance.

Free Weights. Free weights, such as barbells and dumbbells, can be used to provide resistance. Lifting free weights has many advantages. People do not need expensive equipment or even a gym membership to lift free weights. At home, they can use heavy objects—such as canned goods, bricks, or bottles of water—to exercise their muscles.

Moving and controlling free weights takes great focus and helps people improve their coordination skills. People who have injuries or limited movement can adjust the way they lift free weights to accommodate their needs. In addition, lifting free weights exercises many muscles at once, even ones that are not being specifically targeted. For example, if people stand and raise weights in front of them, the muscles in the abdomen and back will work to help keep the body steady.

Nevertheless, there are some disadvantages to lifting free weights. If people do not use proper form while lifting weights, they may risk serious injury. To prevent injury, people should not lift weights that are too heavy. Furthermore, they should always lift weights—especially heavy weights—with another person, known as a “spotter,” to ensure they are using correct form. Other disadvantages involve the storage and cost of free weights. Storing free weights and designating an area to lift can be an issue in homes with little free space. Free weights can also be costly if people purchase multiple pieces of equipment, such as weight benches, bars, and weight plates.

Weight Machines. Weight machines are relatively easy to use. People position themselves on the machines, move a pin in the weight stack to the desired weight, and then move the machine by either pushing or pulling on handles or bars. They are safer to use than free weights and do not require as much coordination. Still, people must use good form on the machines so they do not injure themselves, and they should avoid lifting weights that are too heavy.

Using weight machines has several disadvantages. They are large and expensive, so most people must join a gym to use them. Machines usually target only one set of muscles, which means a person must use multiple machines to work different muscle groups. People who are not of average size may have difficulty using the machines correctly, and most machines cannot be adjusted to accommodate people who have limited movement or injuries.

Stretchable Tubing. Stretchable or resistance tubing is made of elastic tubes that stretch to provide resistance. They come in different sizes and thicknesses, which create more or less tension. To use them, people put them around a body part and pull on them to create tension. This causes the muscle to contract. Stretchable tubes are inexpensive, portable, easy to use, and take up little space. They can also target a variety of muscle groups. However, these tubes lose elasticity over time and may need to be replaced. Additionally, they can snap and cause injury.

Body Weight. People do not need free weights, machines, or stretchable tubing to strength train. They can use their own body weight as resistance to perform exercises such as abdominal crunches, leg squats, lunges, pull-ups, push-ups, and more. These types of exercises use the weight of a person’s body as resistance. The major advantage to using one’s body weight is that it is free. No special equipment is needed. Also, exercises that rely on body weight can be performed anywhere. A disadvantage to this form of strength training is that the resistance cannot be decreased. Yet, resistance may be increase by altering the way some exercises are performed.

BENEFITS OF STRENGTH TRAINING

Strength training has many benefits. These benefits include improved athletic performance, injury rehabilitation, weight loss and stress, and to combat effects of ageing. According to the American College of Sports Medicine, a person should work out all the muscle groups to fatigue at least two to three days a week with rest days in between active workout days to achieve maximum results. The major muscle groups include the abdominals, arms, back, chest, legs, and shoulders. Working out a muscle to fatigue means people should perform an exercise with weights that are heavy enough so that they can only perform eight to twelve repetitions. This is just an average number and can change depending on several factors, such as the age, health, goals, and strength of a person.

Strength training is one of the primary methods used by persons to improve athletic performance. Strength training programs can improve an athlete’s muscle power and economy. An improvement in economy allows an athlete’s body to burn through less energy at lower levels of intensity, as well as slowing down the draining of carbohydrate stores. An improvement in muscle power allows an athlete to increase the amount of force produced which can improve performance.

Injury rehabilitation, facilitated by a physical therapist, often utilizes body weight, resistance bands, and at latter stages weight machines, to regain muscle strength and function. Regaining muscle strength is accomplished through a focus on stabilizing muscles. Increased function is accomplished through a program designed to increase the muscles range of motion.

Research has indicated that the average American does not move enough and leads a sedentary lifestyle. Many people have jobs that keep them inactive during the day. In addition, many people spend much of their free time doing sedentary activities, such as watching television or playing on computers, instead of engaging in physical exercise. These conditions can lead to weight gain and stress. Strength training releases the brain neurotransmitters dopamine and serotonin, which when released help combat depression. Muscles during strength training also burn through carbohydrates, which when combined with a healthy diet, results in weight loss.

Research has shown that specific effects of aging on the brain, muscle strength and muscle density, can be slowed down through the incorporation of strength training. Strength training increases neurogenesis, neuroplasticity, and cognition performance, slowing down the deterioration of brain function. After the age of thirty, people lose five pounds of muscle every decade. In addition, people lose bone density as they age. Research has proven that performing resistance exercises can help slow or even reverse age-related muscle and bone loss. Strength training also helps to reduce the loss of motor function.

RISKS OF STRENGTH TRAINING

Strength training can also have harmful effects on the body. These effects usually occur due to overtraining or improper technique. Through proper research and consulting with strength and conditioning professionals, the risks of strength training can be greatly reduced.

Overtraining occurs when the intensity and frequency of strength training routines over an extended period of time doesn’t allow the body significant time to recover. This has a variety of negative consequences, including muscle weakness, decreased athletic performance, reduction in quality of sleep, and increased resting heart rate. Overtraining is easily preventable by recognizing body fatigue and allowing ample time for the body to recover following strength training.

Improper technique occurs when a strength training exercise is done incorrectly. This can have immediate and long-term effects on the body. Improper technique adds additional pressure on joints and muscles, stretching of soft-tissue muscle, and can make preexisting injuries worse. Ways to avoid improper technique involve the use of a spotter to monitor exercise, proper research on exercises, and avoiding continuing exercise when muscle fatigue occurs.

For Further Information:

1 

Collins, A. Strength Training Over 40: A 6-Week Program to Build Muscle and Agility. Rockridge Press, 2020.

2 

Haff, G. Gregory, and N. Travis Triplett. Essentials of Strength Training and Conditioning. 4th ed., Human Kinetics, 2016.

3 

Hunt, K. Beginner’s Guide to Weight Lifting: Simple Exercises and Workouts to Get Strong. Rockridge Press, 2020.

4 

______. Bodybuilding for Beginners: A 12-Week Program to Build Muscle and Burn Fat. Rockridge Press, 2019.

5 

______. Strength Training for Beginners: A 12-Week Program to Get Lean and Healthy at Home. Rockridge Press, 2020.

6 

Noelle, B. Weight Training for Women: Exercises and Workout Programs for Building Strength with Free Weights 2020.

7 

“Strength Training: Get Stronger, Leaner, Healthier.” Mayo Clinic. Mayo Foundation for Medical Education and Research, www.mayoclinic.org/healthy-living/fitness/in-depth/strength-training/art-20046670.

8 

Derived from “Strength Training.” Salem Press Encyclopedia of Health, Salem Press. Accessed 15 May 2021.

Citation Types

Type
Format
MLA 9th
Wilson, Bradley R. A. "Strength Training." Magill’s Medical Guide, 9th Edition, edited by Anubhav Agarwal,, Salem Press, 2022. Salem Online, online.salempress.com/articleDetails.do?articleName=MMG2022_1295.
APA 7th
Wilson, B. R. (2022). Strength training. In A. Agarwal, (Ed.), Magill’s Medical Guide, 9th Edition. Salem Press. online.salempress.com.
CMOS 17th
Wilson, Bradley R. A. "Strength Training." Edited by Anubhav Agarwal,. Magill’s Medical Guide, 9th Edition. Hackensack: Salem Press, 2022. Accessed September 16, 2025. online.salempress.com.