Plyometrics for triathlon: How do plyometrics help triathletes?

Elite runners' gaits take advantage of plyometric principles
to decrease ground contact time and make their running
more efficient. © AP Photo/Jason DeCrowm File

While speed and agility training help with cycling and swimming, plyometric drills are especially effective speed training drills for running. Paavolainen et al (1999) found that adding plyometric training to the programs of highly-trained runners significantly improved their 5K times. Spurrs et al demonstrated a 4.1% increase in efficiency while running at 10 mph (6 min/mi pace).

Why plyometrics improve running

When you run, most of your power is generated by the spring action of your foot pounding into, and then blasting off the ground again. Each step is itself a tiny plyometric movement, with your muscles overstretching as your foot drives into the ground, and then rebounding with a powerful contraction as your foot pushes off the pavement. The amount of time your feet are in contact with the ground is actually one of the predictors of running speed. Compare how elite runners look, (bounding off the ground with each step) compared to the old man who plods around your neighborhood every morning with one foot always planted firmly on the ground. Who's moving faster? Plyometric speed training drills such as standing jumps, bounding, and skipping teach you to reduce your ground-contact time, thus maximizing your muscles' recoil and the power with which you push off the ground: all of which make you run faster.

Another speed-killer that plyometrics address is fatigue. Think of how most runners' strides look at the end of a marathon: dragging their feet along the ground in a sad shuffle. While they may have started with an efficient gait, keeping ground contact time to a minimum, by the last 10K they look more like the old man running around your neighborhood. Fatigue is the enemy of efficient running form. As you get tired, your muscle contractions are less coordinated and thus less efficient. As you spend more energy running badly, you get even more tired, and run even more slowly. Plyometric run training teaches your muscles to activate more efficiently, delaying fatigue and keeping muscle activation (and speed) high even as fatigue sets in.

For an excellent explanation of the importance of strengthening neuromuscular pathways, read Matt Fitzgerald's Brain Training for Runners.

References: Mauro, P.; Using Plyometrics to Improve your Triathlon Performance; 2005
Paavolainen et al; Explosive-strength training improves 5-km running time by improving running economy and muscle power; Journal of Applied Physiology; 1999