Swimming fast with the least possible energy expenditure is the goal in triathlon.
Credit: Al Bello/Getty Images
In Part I, we started our swim lesson, led by Jonty Skinner, director of performance science and technology for USA Swimming. We learned about quadrant swimming, breathing and head position, and front-quadrant loading. This article continues to look at what triathletes can learn from the world's top swimmers.
Flat Body Position vs. a Rotated Body Position
Some of the beginning swimmers I coach have been so focused on form drills and body rotation that they actually over-rotate. However, Jonty sees more pool swimmers with a flat body position. Either extreme, flat body position or over-rotation, produces sub-optimal results. What does a good rotation look like?
Good rotation is a combination of angle and timing. Take another look at Photo Set 2 below. In the top frame (2002), Kayln's hips are rotated; but her head is lifted, causing her hips to fall farther below the water surface than the 2004 frame below.
In the 2004 frame, her hips have already rotated toward her left side creating power through body roll. Think about a baseball player or a golfer trying to hit the ball using only his or her arms—the potential power using arms alone is far less than what's possible when several muscle groups are used. This power generation is why swimmers should use the entire torso to initiate the freestyle stroke.
Also notice in this photograph that Kayln's body is much higher in the water in the 2004 frame than in the 2002 frame. If she's positioned higher in the water, she uses less energy to propel herself. In triathlon, it's important to limit the energy expenditures in swimming in order to have enough energy to complete the remaining two events.
Photo Set 2
In order to get a better feeling of a high body position in the water, wear a wetsuit. Notice how easy it is to glide through the water when you're positioned higher?
High Elbow vs. Straight Arm Pull Underwater
In Photo 2, the 2002 frame, Kayln's right elbow is low in the water and her arm has less bend than the 2004 frame. A high-elbow and bent-arm position is much more powerful than a straight-arm pull because you're engaging larger muscles and getting more leverage.
For example, try to get out of the pool without bending your arms to hoist yourself on deck. It's impossible. Now, get out of the pool the easiest way you can—I bet your arms are bent. Of course, my example is exaggerated because your arm, hand and body positions aren't the same exiting the pool as they are in swimming, but I think it makes the point.
Tempo vs. Distance per Cycle
Swimming is similar to cycling and running in that there's an optimal cadence range for top athletes. For cycling, the optimal cadence is somewhere between 80 and 100 pedal revolutions per minute (rpm.) If the pedaling rpm is too low, the athlete is likely mashing the gears, causing greater stress on the knees and more muscular fatigue. At the same time, spinning the pedals at 120+ rpm is good for powerful track sprinters going relatively short distances; but doesn't work well for longer cycling events.
World-class swimming cadence is typically 40 to 55 cycles per minute. A right-arm entry to the next right-arm entry equates to one cycle. Top women are on the higher end of the spectrum, and men are on the lower end. Because women aren't typically as strong as their male counterparts, they utilize higher cadences instead of strength to generate speed.
For example, Janet Evans swims 55 cycles per minute and Brooke Bennett swims 53 to 54 cycles per minute. Grant Hackett is at 40 and Larsen Jensen is at 38 cycles per minute.
In wavy, open water conditions, Jonty notes that it's important for triathletes to keep cadence high—particularly in windy, wavy water with chop. A swimmer with low turnover will be tossed around more than a swimmer with a higher turnover. Getting tossed around can potentially increase form drag and result in a higher metabolic cost.