Several performance components affected by strength training can boost your triathlon results. The first component is muscular power. Power is the ability to produce force quickly. In triathlon this is useful during short sprints, uphill cycling, and transitioning into and out of the water. A powerful muscle is able to call upon its anaerobic energy to provide quick movement. Strength training increases muscular power in two ways: The more muscle you have, the less effort it takes to produce a given amount of power (remember the SUV analogy), and strength training trains you muscles to reproduce energy quickly so they don’t tire as fast and can recover from short bouts of high-intensity movement. Energy production is achieved deep down in the muscle fibres, where the stores of glycogen (the storage form of glucose), enzymes that increase the speed of muscular contraction, and stored creatine and phosphocreatine (energy substrates) are all increased because of strength training.
The second component is that you can increase in every event through strength training. This is the result of selective recruitment of fast-twitch muscle fibres during strength training. During endurance training you mainly use toy slow-twitch fibres, which are designed for low power output and long-term use. During strength training you have to call upon the fast-twitch muscle fibres for their high power and force output. The downside to fast-twitch fibres is that they fatigue very quickly – usually in less than five minutes. When you are endurance training and decide to put on a burst of speed, you know that it won’t last very long and that you’ll have to slow back down your regular pace. Strength training builds up the ability of the fast twitch muscle fibres to activate and provide that burst of speed. You will have to slow back down, but you can obtain a higher-intensity burst of speed (meaning faster) that you will recover from faster, so you can do it again when you need to.
The third component that strength training improves has an indirect effect on your immediate performance: a reduction in body fat is typically equated with losing fat but the equation has two sides – you can also increase lean tissue. Endurance training burns a lot of fat, but it doesn’t build much lean tissue. Strength training is all about increasing lean tissue. Again, we are not talking about body-building size muscles, but about making muscles you have more dense. Increasing muscle density bring down your fat-to-lean ratio, which equals improved performance because fat doesn’t assist in movement – all it does is sit there, needing muscle to move it along. Increase lean tissue means more muscle to produce movement, which is exactly what you want, because muscle essentially carries itself – it isn’t a freeloader like fat.