The crawl, also called the front crawl or freestyle, is the fastest and most common swimming stroke. You lie face down in the water, alternate your arms in an overhead windmill motion, and kick your legs in a rapid up-and-down flutter. It’s the stroke you’ll see in nearly every freestyle race, and it’s the first powerful stroke most swimmers learn after the basics. A 150-pound person swimming front crawl at a moderate pace burns roughly 594 calories per hour, climbing to about 716 calories at a vigorous effort.
Why It’s Called “Freestyle”
In competitive swimming, “freestyle” doesn’t technically mean front crawl. Under World Aquatics rules, freestyle simply means a swimmer may use any stroke. But because the front crawl is significantly faster than butterfly, backstroke, or breaststroke, virtually every competitor chooses it for freestyle events. The rules are minimal: some part of your body must break the water’s surface throughout the race (except for up to 15 meters after a start or turn), you must touch the wall at each end, and you can’t walk along the bottom. In medley events, the freestyle leg must be a stroke other than the three already swum, which again defaults to front crawl.
How the Arm Stroke Works
Each arm cycle has four phases: entry, pull, push, and recovery. During the entry, your hand slices into the water ahead of your shoulder and extends forward. The pull phase draws your hand downward and back underneath your body. This is actually the slowest phase of the stroke, where your hand anchors against the water and begins generating force. The push phase follows immediately, sweeping your hand past your hip, and research from motion-capture studies shows this is the most consistently propulsive phase for the whole body regardless of what the other arm is doing.
Recovery is the above-water portion, where your arm swings forward through the air to begin the next stroke. Interestingly, the recovery phase creates a small net drag on your body, except during the brief moment it overlaps with the opposite arm’s push. This is why good timing between arms matters so much. When one hand enters the water while the other is in its pull or push phase, the combined effect is propulsive for the whole body.
The Flutter Kick
Your legs move in a continuous alternating pattern called the flutter kick. The motion originates at the hips, travels through relaxed knees, and ends with a whip-like snap of the feet. Your ankles need to stay loose so your feet act like flexible fins rather than rigid paddles. Stiffening the ankles in the lower leg actually helps stabilize the joint and reduce drag, but the range of motion should still feel natural rather than locked.
All effective kick rhythms are built on a two-beat foundation, meaning each leg kicks once per full arm cycle. This basic pattern matches the side-to-side rotation of your body. A six-beat kick layers two additional smaller kicks per leg on top of that same base, adding propulsion and helping counteract the sinking force that the arm pull creates at your hips.
Which kick rate to use depends on distance. In short sprints of 50 meters or less, a full six-beat kick maximizes speed with little concern for energy conservation. In distance events like the 1500 meters, most swimmers scale back to a two-beat or four-beat kick to conserve their legs, saving the six-beat for a final sprint.
Body Rotation and Position
The front crawl isn’t swum flat on your stomach. Your shoulders roll along your body’s long axis with each stroke, and the optimal rotation falls between 40 and 50 degrees to each side. This rotation serves multiple purposes: it lets your arms reach farther forward during entry, engages the powerful muscles of your back and torso during the pull, and reduces the frontal area of your body pushing against the water. Swimmers who stay too flat lose power and create more drag. Those who over-rotate waste energy and lose streamlining.
Your head position anchors everything. Most coaches recommend looking slightly forward and down, with the waterline hitting near your hairline. Lifting your head too high drops your hips and legs, creating drag that slows you down far more than any arm technique error would.
Breathing Technique
Breathing in front crawl happens by turning your head to the side during the recovery phase of one arm. Your mouth clears the water in the small trough that naturally forms alongside your head as you move forward. You exhale steadily underwater through your nose or mouth, then take a quick inhale when you rotate.
Bilateral breathing, alternating the side you breathe to every three strokes, helps prevent muscular imbalances that develop from always rotating to one side. It also lets you see competitors or open water conditions on both sides. The trade-off is that breathing every third stroke delivers slightly less oxygen than breathing every second stroke, which is why many swimmers practice bilateral breathing in training but revert to their stronger side during races, especially in sprints where oxygen demand peaks.
Some swimmers with shoulder injuries or deeply ingrained habits find bilateral breathing impractical. That’s common and not necessarily a problem, though it can reinforce asymmetry over years of training.
Muscles Used in the Crawl
About 85% of your forward propulsion in front crawl comes from your upper body. The biggest contributors are the large back muscle that runs from your mid-back to your arm (the lat), the chest muscles, and the muscles on the front and back of your upper arm. These generate the force during the pull and push phases.
Your core muscles, including the abdominals and the muscles along your spine, act as stabilizers that transfer power between your upper and lower body and maintain your streamlined position through each rotation. The oblique muscles on the sides of your torso are especially active during the twisting motion of each stroke cycle. In your legs, the front and back thigh muscles drive the flutter kick, while the lower leg muscles co-activate to stiffen the ankle and reduce drag during each kick.
Three Styles of Crawl Technique
Not all front crawl looks the same. Coaches generally recognize three variations: hip-driven, shoulder-driven, and hybrid (sometimes called loping or galloping freestyle).
- Hip-driven: The slowest stroke rate, typically under 75 strokes per minute. The hand pushes forward after entry rather than immediately pulling down, creating a brief glide. Power initiates from hip rotation. This style conserves energy and suits distance events of 400 meters and longer, as well as warm-ups.
- Shoulder-driven: The fastest stroke rate. Arms turn over quickly with minimal glide, and propulsion relies more on rapid arm turnover than hip rotation. This is a sprinter’s technique.
- Hybrid: A stroke rate between the other two, borrowing elements of both. Many 100- and 200-meter swimmers use this approach, balancing speed with sustainability.
Choosing the right style matters for performance. Hip-driven technique simply cannot generate the speed needed for a 50 or 100-meter race. Shoulder-driven technique burns too much energy to sustain over 400 meters or more.
A Brief History of the Stroke
Over-arm swimming strokes existed at least 2,800 years ago among the Assyrians and Greeks, and variations of the crawl were the natural style of South Sea Island natives, North American Indians, and the Kaffirs of South Africa. Europeans lost the technique during the Dark Ages, when swimming fell out of favor over fears it could spread disease. When swimming revived in Europe around the 16th century, it started with a basic dog-paddle, eventually developing into the breaststroke used in London’s first organized races in 1837.
A memorable turning point came in 1844, when two North American Indians, known as “Flying Gull” and “Tobacco,” raced an Englishman named Kenworthy in London using their native over-arm stroke. The English side-stroke and its variations dominated competitive swimming through the late 1800s, but Australian swimmers eventually refined the over-arm technique with a continuous flutter kick, producing the modern crawl stroke that took over racing in the early 20th century.