Sprint designed to tweak ‘fast twitch muscle fibers’
Fitness information seekers will eventually run across an article related to fast twitch and slow twitch muscle fibers, and how certain exercises target one vs. the other. That’s an interesting topic that has far-reaching applications within the research and medical communities.
Generally, fast twitch muscle fibers are responsible for short, quick contractions, while slow twitch muscle fibers hold greater endurance properties.
Cardiovascular activities such as running or biking are more reliant upon slow twitch fibers, simply because these activities are performed at a moderate or lower intensity level for longer periods. But a jog can become a sprint in a matter of seconds. When the pace escalates, fast twitch muscle fibers are recruited.
But what’s the point? Why does it matter which type of muscle fibers we recruit? It matters because you want to train in a way that is consistent with the goals of your exercise program.
This is the physiology behind the training parameter known as “specificity.” Fitness information seekers will also have read about the principle of specificity. Basically, it states that the results of your exercise program are determined by the training you do (exercise type, duration, frequency, intensity, etc.).
If an individual chooses to spend 45 minutes biking at a moderate or low intensity for four or five days per week and does nothing else, that exercise program will naturally engage a higher percentage of slow twitch muscle fibers. These muscle fibers will experience greater endurance and, eventually, the individual will be able to perform a higher workload without tiring.
Conversely, those interested in becoming skilled at short, quick movements for sports such as basketball or volleyball will want to engage in training targeting fast twitch muscle fibers. If you want to sprint, train for sprinting.
This week’s exercise is designed to recruit a higher percentage of these fibers and produce increased quickness and agility. The Eccentric Load Sprint is a movement that will challenge pretty much anyone, regardless of fitness level.
1. Use a plyometric platform or aerobics step 1 to 3 feet tall. Stand on top of the platform with your feet shoulder-width apart.
2. Jump off.
3. Just as you land, allow both knees and hips to bend and soften the landing.
4. Once you feel your legs absorb the landing, quickly push off your left foot and sprint 6 to 8 feet to your right.
5. Move back to the step and do five repetitions of the jump and sprint, then switch sides and sprint to the left for five reps.
6. Perform two sets on each side.
The intensity of the Eccentric Load Sprint can be adjusted by increasing or decreasing the height of the platform. Those with higher fitness levels can start from a higher point, and vice versa.
The key to performing this exercise correctly is to feel exactly when the lower body muscles have been loaded just the right amount before taking off in the sprint. Waiting too long will waste the potential energy created from the landing, and going too quickly won’t allow the energy to build up enough.
Practice this one a few times before going full speed, as the technique takes a little time to master. Enjoy!