Flawless Physio Logo

Does Swimming Build Muscle?

Minute Read


Posted 8 months ago


Last updated: 30/11/2022


by James McCormack

Does Swimming Build Muscle? Yes. But as swimming is an endurance exercise so when compared to heavy weight lifting is not in the same league for developing muscle bulk. If you want to build large muscles, you are better off going to the gym and lifting heavy weights. However, like with other endurance sports, it does build endurance strength in the muscle, which often results in a lean but toned body with strong muscles. Swimming is a sport that works most of the muscles in the body it is an effective exercise to get stronger in general, in particular the upper body and core muscles.

As swimming is a non-weight-bearing exercise it is often used as a form of exercise during recovery from injury or for cross-training, from other more impactful exercises such as running. The core strength gained from swimming is also effective to aid many other sports.

Does Swimming Change Your Body Shape?

If you look at elite swimmers they often have a similar body shape. Broad shoulders, muscular backs, narrow hips, long arms, and large hands and feet. But are these pre-existing body shapes that have made them great swimmers, or are these shapes developed through swimming?

Maybe a bit of both. Feet and hands are not going to change with training, and neither will arm length or hip width. The musculature of the back, shoulder and arms, and therefore how broad their shoulders look are going to be influenced by the thousands of lengths of of the pool that they swim.

What Muscles Does Swimming Work?


The legs muscle account for greater propulsion with breaststroke than all the other strokes. In particular the abductor and adductor muscles of the hips. These are the muscles that move the hips and legs out and in together, respectively. The arms create a circular movement so use many muscles, with the most powerful movement working the pectoral muscles of the chest.

Related article: Swimmers Knee

Front crawl

Front crawl is a more balanced stroke with the use of muscles of the whole body. Dependant on the style of swimming, this is usually a more upper body dominant stroke for forward propulsion. The powerful propulsion comes from the latissimus dorsi, and internal rotator muscles such as the pectoral muscles, sub scapularis, and serratus anterior. The deltoids, trapezius and external rotator muscles work when the arm recovers over the water.

The kick is from the hip and therefore uses the gluteal muscles and hamstrings. The core muscles are essential to keep the body straight and resist the forces generated by the limbs to keep the swimmer moving efficiently and straight in the water.


Butterfly is a challenging stroke with the arms generating the majority of the forward propulsion, from the latissimus dorsi, pectorals, as well as subscapularis and serrated anterior. This stroke also requires a lot of strength for arm recovery over the water. Both arms simultaneously move overhead, using the deltoids and upper trapezius muscles. To maintain forward propulsion as the arms recover over water, the legs kick powerfully together using the hip flexors, quadriceps, glutes and hamstrings.


Backstroke as with most of the other strokes, uses the powerful latissimus dorsi muscles for propulsion, along with the deltoids and triceps. The legs are less powerful in the backstroke but use the glutes, hamstrings, hip flexors and quads. The core muscles are also necessary to keep the body in alignment as this is a unilateral stroke.

Physiotherapy with James McCormack

This is not medical advice. We recommend a consultation with a medical professional such as James McCormack. He offers Online Physiotherapy Appointments for £45.

Share this page