Fast swimming is determined by a number of factors – physiological, psychological, biomechanical, etc. A swimmer may be so gifted in one attribute (e.g. strength, lung function, pain tolerance) that it offsets his/her technique limitations. A swimmer with a high maximum oxygen uptake (75 ml/kg/min) or a high peak hand force (60 lbs) can have substantial technique limitations and still swim very fast.
Our research shows that faster swimmers have more effective technique than slower swimmers. However, our research also shows that even the fastest swimmers have limiting factors. If you copy the technique of an Olympian, you risk adopting their limiting factors as well as their positive technique elements.
A characteristic technique element of an Olympian may be obvious, but not necessarily helping him/her swim faster. It’s vital to differentiate between characteristic technique and effective technique, especially in Olympians.
Hand force is the single most important factor in swimming propulsion. Research shows that hand force is directly related to swimming speed – the greater your hand force, the faster you swim. Research also shows that faster swimmers generate more hand force than slower swimmers. While most swimmers have peak hand force values of less than 50 lbs (220 N), Olympians generate as much as 80 lbs (350 N). The arms account for about 80% of total propulsion and hand force accounts for about 80% of arm propulsion, so learning how to position your arms to generate maximum hand force throughout the stroke cycle is essential to swimming your fastest.
Most swimmers can increase hand force by increasing hand speed throughout the stroke cycle. Improving bilateral symmetry, minimizing wasted motion, and decreasing force losses will help to increase the average force on each stroke.
The arm can move into stronger and stronger positions at faster and faster speeds throughout the stroke cycle. Hand force peaks about halfway into the push phase (after the arm passes the shoulders) for freestyle, butterfly and backstroke. For a swimmer with effective technique, the force value on the push phase is typically twice as much as on the pull phase.
The entire stroke cycle is important. Most swimmers don’t take full advantage of the push phase because the arm exits prematurely. Maintaining the elbow below the surface can increase the force and time of the push. A swimmer who does not double the force from the pull to the push has a major technique limitation.
Three contributing factors to shoulder injuries are: overuse (excessive training distance), ineffective technique, and inadequate strength training. Any single factor can cause injury, but a combination is often responsible. A decrease in training distance, a change in technique to decrease stress on the shoulder, and strength training that targets muscular imbalances are all necessary to recover from a shoulder injury.
No. In freestyle, the torso rotates about the polar axis (a reference axis through the center of the body from head to feet). Summation of forces requires that successive body segments (e.g. torso, upper arm, lower arm, hand) rotate in the same direction (as in throwing). The freestyle arm motion is perpendicular to the torso rotation and the hand force cannot be increased by the force of hip rotation. Although the timing of the push phase in freestyle is usually simultaneous with torso rotation, rotating the hips harder or faster will not increase hand force. Exaggerated torso rotation can even produce counterproductive motions.
It is appropriate to glide when the body is moving faster than swimming speed. For example, when the body enters the water after a start or leaves the wall after a turn, it is moving faster than swimming speed and gliding is appropriate. There is one other time when gliding may be appropriate. During breaststroke, for a fraction of a second after the kick, the body may be moving faster than swimming speed. When this is the case, it is counterproductive to immediately begin the arm motion.
No. Gliding in freestyle (usually associated with “catch-up stroke”) is counterproductive. During a glide phase, there is no propulsion from either hand. The body slows down and requires considerable energy to speed up. The energy cost of speeding up on every stroke is greater than maintaining a relatively constant speed. Gliding in freestyle is biomechanically ineffective, physiologically inefficient, and anatomically stressful.
Reducing the body cross-section (the area perpendicular to the direction of body motion) is the most important factor in swimming resistance. Keeping the hips and legs directly behind the shoulders minimizes the cross-section.
Counting strokes is the easiest way to measure technique, but not the best. A decrease in stroke count does not always indicate a more effective technique. An increase in stroke count does not always indicate a less effective technique. The active drag coefficient is the most accurate measure of swimming technique.
Skills must be learned at a slow swimming speed. Once a swimmer has learned to control his/her movements at a slow speed, gradually increasing the stroke rate will help a swimmer maintain control at faster speeds. Individual instructional sessions and regular analysis sessions expedite the learning process.
No. One of the many misconceptions about swimming technique is that the head must be submerged for the legs to stay behind the shoulders and minimize resistance. A more effective way to minimize the body cross-section is to arch the lower back to bring the heels to the surface. Maintaining the water level just above the hairline puts the head in an optimal nonbreathing position that also minimizes the head motion necessary to breathe.
If the elbow is flexed and the forearm is vertical, the hand must be lateral (to the outside of) the shoulder. As force is applied during this motion, torque is generated and the body twists about the antero-posterior (front to back) axis. The twisting increases resistance and slows swimming velocity. It is more effective to diagonally orient the forearm during the pull phase, so that the hand passes beneath the head. The swimmer will benefit from the improved mechanical advantage of the elbow angle and have the arm in a stronger position to generate force on the push phase.
While it’s possible for paddles to cause an overload on the shoulder joint, it is far more likely that an ineffective technique is to blame for a shoulder injury. For example, if the arm entry on freestyle is parallel to the surface, the arm is in a weak and awkward position that can stress the shoulder when the pull begins. Swimmers often continue torso rotation after the entry is complete, which further stresses the shoulder. If additional stress is added with paddles, the combination of these three factors is equivalent to a “perfect storm” for the shoulder.
If hand paddles cause shoulder pain, it is advisable to stop wearing them during conditioning. Paddles can serve a very important purpose, however, during technique work. Paddles slow the hand speed and make it easier to track the hand path that is within the swimmer’s field of view. Paddles also make the orientation of the hand on entry and exit more obvious. The enhanced feedback is vital to improving technique to overcome the injury.
In spite of advertising claims, improving technique is far more complicated than just wearing a piece of plastic on your hands. There is no research that supports an improvement in technique by simply training with a specific paddle design. The paddle goes where the hand takes it, not the other way around. The strength training benefit of paddle design, however, has been documented.
If you do the math, it’s easy to understand why there’s not more time for instruction during a team practice. On a typical team, a coach will have 30 swimmers for a 2 hour workout. If only 30 minutes of the coach’s time is taken up by explaining sets, fixing goggles, checking performance times, etc, he/she has 90 minutes left. If the coach uses all of the remaining 90 minutes for technique instruction, each swimmer gets 3 minutes of individual attention per workout. On the average, 3 minutes is only enough time for a coach to evaluate and interact with a swimmer about a single technique element.
Although 10,000 hours is considered a necessary minimum to develop expertise in any field, simply putting in 10,000 hours does not guarantee expert level performance. Many swimmers have trained for 10,000 hours by the time they finish high school. Very often they have considerable expertise in training (maintaining effort level, making difficult intervals, etc), yet still have not mastered technique. Swimmers must practice with cue-focused strategies for the hours to count towards making them an expert.
In attempts to get swimmers to maximize effort, care must be taken to avoid counterproductive actions. For example, Aquanex testing shows that swimmers emphasizing hip rotation in freestyle often slide their hand sideways and upwards on the push phase in the same direction as the hips, resulting in a sudden loss in hand force. Recent research by Dr. Tim Henrich (presented at BMS 2010 in Norway) found that contracting abdominal muscles decreases pulmonary function. Pioneering work by Dr. Jan Clarys (one of the world’s leading biomechanists for over three decades) showed that more skilled swimmers only used muscles critical for an activity, while less skilled swimmers also activated nonessential muscles. An increased effort is more likely to improve performance if there no negative aspects from actions that increase resistance or fatigue.
There are at least three reasons not to use a straight arm recovery in freestyle. 1) If the arm is straight as it exits the water, the upward arm motion will force the body further underwater and cause needless fatigue. 2) If the arm is straight as it recovers through the air, it is more likely to stress the shoulder. 3) If the arm is straight on entry, misdirected force will waste time and energy. While some swimmers may benefit from improving their push phase in an effort to straighten the arm for recovery, it is far better to improve the push phase independently of the arm recovery.
It depends on the individual. If a swimmer’s legs are below the torso causing an increase in the body cross-section, decreasing resistance could make a sudden improvement in performance. A swimmer who has .2 sec of wasted arm motion at the beginning of each stroke cycle, would see a dramatic time drop from adjusting the arm motion to generate more propulsion.
There is data that shows that some swimmers use a different technique for short course and long course. However, an optimal technique would be identical for short course or long course. Minor differences in stroke rate and stroke length would be related to the distance of the swim, as opposed to the distance of the course.
Probably more important than “how big” is “how many” misconceptions are prevalent in swimming. And maybe even more important is “how long” will these misconceptions endure? At least one misconception (that catch-up stroke is a viable competitive stroke) persists – even after 56 years of research (not to mention principles of mechanics, physiology, and anatomy) unequivocally prove otherwise. I was prompted to address this question because of a comment made by Nobel Laureate Dr. Harold Kroto at a sport psychology conference. In a presentation on creativity in science and art, he explained that people are generally willing to accept “conventional wisdom” without any supporting facts.