Swimming: Freestyle

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton and Kim Jackson  

Introduction[edit | edit source]

Freestyle swimming2.gif

The freestyle stroke, also known as front crawl, is the fastest and most efficient of the swimming strokes used in competition.

  • Swimming is a unique activity because it requires primarily the upper body for the propulsive force, with 90% of the driving force provided primarily by the torque generated from the shoulder[1].
  • Freestyle gives a full body workout. It works the muscles in your arms, legs, core and back.
  • Your legs are an important part of freestyle however they provide just about 10 percent propulsion in the bodies of practiced swimmers[2].

Basics[edit | edit source]

The freestyle swim stroke is a complex sports motions. Numerous muscles starting from the finger and ending in the feet are in constant motion, creating and resisting forces in the process. While one side of the body is performing an active motion, the other side must relax and stabilize parts of the body to allow this motion to happen[3].

When swimming this stroke, the body will be in a prone position (on the stomach and face toward the water).[2] The freestyle stroke is divided into six phases:

  1. Hand entry
  2. Forward reach
  3. Pull through
  4. Middle pull through
  5. Hand exit
  6. Middle recovery[1]

The Upper-Body Muscles and Joint Kinematics[edit | edit source]

It is important for the athlete to have a properly balanced shoulder regarding muscle strength. Improper muscle balancing can cause the onset of shoulder pain (see Swimmers overuse injuries).  An absolute or sudden increase in training load and poor technique can also be associated with the onset of pain. The coaching staff can observe a dropped elbow during the recovery phase of the freestyle stroke as one of the early signs of possible injury[1].

  • Stroke power is achieved through the shoulder adductors, extensors, and internal rotators with the serratus anterior and latissimus dorsi being the key propulsion muscles for swimmers. Because the trunk is rotated away from the side that is beginning to pull, the shoulder avoids a true impingement position of forward flexion with internal rotation and horizontal adduction.[4]
  • The swimmer engages their shoulder muscles (deltoids and rotator cuff), the middle back muscles (trapezius) and the muscles around their rib cage (serratus anterior) to help initiate their body’s rotation to help lengthen their stroke and maximise propulsion.
  • The swimmer initiates the catch phase by engaging the muscles in the upper/middle of their back (latissimus dorsi and trapezius) and the chest muscles (the pectorals).
  • The swimmer’s upper arm muscles (biceps and triceps) become engaged to flex and extend their elbow during the propulsive middle and end of the stroke
  • The wrist flexor muscles help to maintain the swimmer’s wrists in the optimum position[5].

The Lower-Body Muscles in Freestyle[edit | edit source]

Freestyle swimming3.gif

Freestyle uses a combination of two types of kick, the flutter kick and the underwater dolphin kick.

  • Both types of kick start with a contraction of the hip flexors (rectus femoris and iliopsoas) during the downbeat which provides the propulsion.
  • As the swimmer extends their knee/s, they engage their thighs (quadriceps).
  • As they recover their leg/s with the upbeat kick, the swimmer’s buttock (glutes) and hamstring muscles contract to extend their hips.
  • Throughout the stroke, the swimmer engages their gastrocnemius and soleus to help maintain a plantarflexed position with their feet (ankles extended & toes pointed)[5]

The Core (Abdominal) Muscles in Freestyle[edit | edit source]

The major core muscles are abdominal muscles.See link.

They help to stabilise the swimmer’s body, helping it maintain an effective position in the water This helps to maximise propulsion and minimise drag. The swimmer’s core should be engaged throughout the stroke, especially during both the arm pull and the leg kick phases.[5]

Freestyle Body Type[edit | edit source]

Swimming 4x100m freestyle relay 2017-08-07 06 (cropped).jpeg

The Swimmer's Body: The best swimmers are very tall, often with unusually long torsos and arms. They have large feet and flexible ankles–great for kicking propulsion. Swimmers carry more body fat than other endurance athletes: 10-12% for men and 19-21% for women.

  • Center of Mass: Every swimmer has a balancing point in the water (center of mass) and the closer it is to the centre of flotation (the lungs), the easier it is for the body to float horizontally with little or no effort on the part of the athlete. Having the centre of mass near the lungs is one of the main reasons why many elite swimmers have very long torsos often shaped like a triangle.
  • Having flexibility, especially in the shoulders and ankles, is a huge asset for swimmers and is a big asset. Having flexible shoulders allows for swimmers to rotate their bodies while keeping their hold on the water in the long axis strokes. In the short access strokes, swimmers with flexible shoulders are able to press their chest down more, thus lengthening their strokes and making them more efficient. Flexible ankles increase the surface area of the foot, essentially making the foot act more like a flipper and allows you to push more water backward, increasing forward propulsion. Flexible ankles also allow for more force to be exerted by the gluteus maximus and quadriceps, which are two of the biggest muscles in the body.
  • Shorter legs have also been found to be advantageous for swimmers, as they help add more power without creating lots of drag.
  • The muscle fiber makeup of a swimmer (specifically the balance of slow-twitch (ST) and fast-twitch (FT) fibers) is a determining factor in the potential of a swimmer. The athletes with the greatest numbers of FT-A fibers are thought to have the greatest potential in the sport of swimming. They have a potential to swim a wide range of events.
  • The most important attribute for becoming a fast swimmer is mental strength. Discipline, focus, confidence, and a good work ethic are arguably just as important as having physical talent[6].

Energy Expenditure[edit | edit source]

Phelps after 200 backstroke (6421140107) (cropped).jpeg

For the average person who simply wants a good, low-impact workout from of their swimming routine, with an hour in the pool, it will burn a good number of calories. That’s largely due to the fact that swimming is a great cardiovascular workout that challenges the whole body and builds cardiorespiratory endurance.

  • Michael Phelps ate 10,000 calories a day while training for the Olympics[7]. Image R
Freestyle METs Calories Burned

(Weight: 68kg / 150lbs) (Duration: 60min)

Freestyle, Fast (Competitive) 9.6 700
Freestyle, Slow (Recreational) 5.8 414


References[edit | edit source]

  1. 1.0 1.1 1.2 Davis DD, Nickerson M, Varacallo M. Swimmer's Shoulder. Available:https://europepmc.org/article/MED/29262079 (accessed 20.12.2021)
  2. 2.0 2.1 All American swim Different Swimming Strokes and Their Benefits Available:https://allamericanswim.com/different-swimming-strokes (accessed 20.12.2021)
  3. Freestyle Swimming Muscle Analysis 1 A Comprehensive Joint and Muscle Analysis Regarding the Motion of Freestyle Swimming Shawn Mantici and Mike Herrmann Rowan University Available:http://users.rowan.edu/~mantic78/Muscle.Anaylis.Paper.pdf (accessed 21.12.2021)
  4. Tovin BJ. Prevention and treatment of swimmer's shoulder. North American journal of sports physical therapy: NAJSPT. 2006 Nov;1(4):166.Available:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953356/ (accessed 20.12.2021)
  5. 5.0 5.1 5.2 eatsleepswim coach Muscles during freestyle Available: https://www.eatsleepswimcoach.com/muscles-during-freestyle/ (accessed 20.12.2021)
  6. Swimmers world The perfect body type Available: https://www.swimmingworldmagazine.com/news/what-makes-the-perfect-swimmers-body/(accessed 21.12.2021)
  7. Openfit calories burned during swimming Available:https://www.openfit.com/calories-burned-swimming (accessed 21.12.2021)
  8. Conquer Swimming How many calories burnt in swimming Available:https://www.conquerswimming.com/how-many-calories-does-swimming-burn/ (accessed 21.12.2021)