What Makes Your Muscles Get Stronger?

By: Kian Kardestuncer, Lindsay Arthurs, and Dalya Munir. Kian is a recent Middlebury College graduate and former varsity squash player pursuing admission to medical school, Lindsay is an SOVT athlete and SOVT Health Intern. Dalya is a current medical student at the University of Vermont Larner College of Medicine.

Have you noticed that a weight feels easier to lift after a few weeks? Maybe you can do more push-ups. Or maybe a move in your sport feels easier.

Your body gets stronger as it responds to exercise. This happens in 2 main ways: your brain gets better at using your muscles, and your muscles grow bigger.

Strength training means doing exercises to help your muscles get stronger. You can use weights, resistance bands, or your own body weight. These exercises challenge your muscles and help you build strength over time.

Your brain helps you get stronger

Your brain and muscles work as a team. When you kick a ball, your brain sends a signal, through a special “highway” called your nerves, to your muscles. The signal from your brain activates your muscles allowing you to move.

Think of your brain as a remote control. A remote sends a signal to a TV. Your brain sends signals through nerves to your muscles.

With practice, your brain gets better at using the right muscles to do a specific task. It also gets better at helping muscles work together. This helps you get stronger.

Think of a sports team at the start of a season. Players are still learning how to work together. With time and practice, their coach helps them work better as a team. Your brain does something similar with your muscles.

Your muscles can grow stronger

Strength training also changes your muscles. When you lift weights or do push-ups, your muscles have to put in effort to push or pull the weight. The effort your muscles use to push or pull a weight is called force. Working against this heavy force makes the movements more difficult. This extra challenge sends signals to your body that help your muscles grow and get stronger.

For example, imagine lifting a heavy weight. At first, it may feel hard. After some practice, that same weight might feel easier. You might then try a slightly heavier weight. This gives your muscles a new challenge.

Over time, your body can respond by building more muscle which helps the muscle you already have grow bigger and stronger.

Where does your body get the materials to build more muscle? From the food you eat! Foods such as beans, eggs, yogurt, and fish contain protein. Your body uses the protein from these foods to help build muscle.

With regular training and enough rest, your muscle fibers may grow bigger. This is called muscle growth. Bigger muscle fibers can often do things like help you lift a heavier weight or jump better.

Think of it like teamwork. When more people work together to complete a task, the team can often accomplish more. In a similar way, having more muscle proteins working together can help your muscles produce more force.

How can you get stronger?

1. Challenge your muscles. Try weights, bands, or exercises like push-ups. An exercise should take effort, but you should still be able to move with control. As it gets easier, try to do it more times or using a slightly heavier weight.

   1. To build muscle strength, a great goal is to do an exercise 12 times. Every time you do the exercise, that is called a rep. Doing 12 reps together is called a set. You want to do 3 sets total, taking a short rest between each set.

   2. For example, you can start by lifting a 10-pound weight 12 times, for 3 sets. When that gets too easy, it means your muscles are getting stronger! Then, you can challenge yourself by moving up to a 15-pound weight for 12 reps and 3 sets.

   3. A challenge should not mean pain. An exercise may feel hard, but it should not hurt. If an exercise causes pain, stop and ask your coach for help. Running a lap may feel challenging. Twisting your ankle can cause pain and injury.

2. Keep practicing. Regular exercise helps your body improve. For many adults, strength training 2 days each week is a good starting point.

3. Eat enough food. Your body needs energy and protein to help your muscles grow and recover.

   1. For example, you can get a well-rounded mix of nutrients by eating scrambled eggs for breakfast, a turkey and cheese slice sandwich for lunch, a warm bowl of chicken and rice soup for dinner, and a cup of applesauce or pudding for dessert.

4. Make time to rest. Sleep and time between hard workouts help you recover. Adults need 7 to 9 hours of sleep every night!

5. Notice your progress. Your muscles do not need to feel sore after exercise to get stronger.

   1. For example, if you can now carry two heavy bags of groceries easily without getting tired, your strength training is working!

You can change exercises to fit your needs. You might use a chair, bands, light weights, or your own body weight. Choose exercises that match your goals and let you move safely and with control.Getting stronger can help you in sports and daily life. You may find it easier to run, climb stairs, or carry things.

The Key Message: Strength is not only about bigger muscles or heavier weights. It is about helping your body do the things that matter to you.

References

1. Currier BS, D'Souza AC, Fiatarone Singh MA, et al. American College of Sports Medicine Position Stand. Resistance Training Prescription for Muscle Function, Hypertrophy, and Physical Performance in Healthy Adults: An Overview of Reviews. Med Sci Sports Exerc. 2026;58(4):851-872. doi:10.1249/MSS.0000000000003897

2. Siddique U, Rahman S, Frazer AK, Pearce AJ, Howatson G, Kidgell DJ. Determining the Sites of Neural Adaptations to Resistance Training: A Systematic Review and Meta-analysis. Sports Med. 2020;50(6):1107-1128. doi:10.1007/s40279-020-01258-z

3. Paluch AE, Boyer WR, Franklin BA, et al. Resistance Exercise Training in Individuals With and Without Cardiovascular Disease: 2023 Update: A Scientific Statement From the American Heart Association. Circulation. 2024;149(3). doi:10.1161/CIR.0000000000001189

4. Bishop DJ, Beck B, Biddle SJH, et al. Physical Activity and Exercise Intensity Terminology: A Joint American College of Sports Medicine (ACSM) Expert Statement and Exercise and Sport Science Australia (ESSA) Consensus Statement. Med Sci Sports Exerc. 2025;57(11):2599-2613. doi:10.1249/MSS.0000000000003795

5. Van Every DW, Lees MJ, Wilson B, Nippard J, Phillips SM. Load-induced human skeletal muscle hypertrophy: Mechanisms, myths, and misconceptions. J Sport Health Sci. 2025;15:101104. doi:10.1016/j.jshs.2025.101104

6. Churchward-Venne TA, Burd NA, Phillips SM. Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism. Nutr Metab. 2012;9(1):40. doi:10.1186/1743-7075-9-40

7. Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376-384. doi:10.1136/bjsports-2017-097608

8. Knowles OE, Drinkwater EJ, Urwin CS, Lamon S, Aisbett B. Inadequate sleep and muscle strength: Implications for resistance training. J Sci Med Sport. 2018;21(9):959-968. doi:10.1016/j.jsams.2018.01.012

9. Special Olympics. Building a Culture of Fitness: Fitness Implementation Guide. Special Olympics; 2024. https://media.specialolympics.org/resources/health/fitness/Special-Olympics-Fitness-Implementation-Guide-2024.pdf

This article gives general health and fitness information. Exercises should fit each person's needs and goals.