Muscle Fibers and Sports Performance

Types of Muscle Fibers and Their Roles in Sports Performance

By Mike Caza, CSCS

Running long distances to get in shape is detrimental to your speed and power output as an athlete unless you are a cross country runner and/or run distance in track. For some reason, many individuals are caught up in this "old school" train of thought that the only way to get in shape for their sport is to run 2-5 miles. Below is an overview and explanation of the different types of muscles fibers and their involvement in sports to give you a better understanding on how distance running reduces power output in muscles.

Muscle fibers are commonly characterized by their speed of contraction. These contractions are called twitches and are the result of a chemical release causing contraction of the muscle fiber. The two types of fibers found in skeletal muscle are …

Slow Twitch (Type I)

Slow twitch muscle fibers generate force rather slowly and have long twitch times. These fibers are generally fatigue resistant and have a high aerobic capacity. These are the primary fibers developed in distance running.

Fast Twitch (Type IIa/IIb)

Fast twitch fibers are essentially the opposite in that they generate force quickly, are highly fatigable and have low aerobic power. These are the primary muscle fibers used in most athletic movements (i.e. sprinting, kicking a ball, doing a layup, hitting a baseball, serving a tennis ball, coming off the line in football etc.)

Fast Twitch (Type IIa/IIb)

Here are some examples of the involvement of FT and ST fibers in sport events:

• 100m Spring - Fast Twitch
• Marathon - Slow Twitch
• Power Clean - Fast Twitch
• Soccer - Fast and Slow Twitch

Responses to performance training on muscle fibers…

• Increased muscle size for greater force development
• Improved anaerobic and aerobic capacities (endurance)
• Increased amount of muscle fibers recruited to improve efficiency and performance.

The Bottom Line

Most sports plays require explosive fast twitch movements done repetitively throughout the duration of a game. Being able to accelerate 10 yards fifty times in a football, soccer, basketball or lacrosse game still has an aerobic component so the key is to make the training anaerobic but within an aerobic time frame. For example, instead of doing a 30 minute distance run, do a combination of different speeds that mimics the running demands of most sports for a total of 30 minutes. Below is a sample conditioning workout that can be done at a track for a speed/power sport athlete:

• Jog 50 meters
• Stride 50 meters (about 40% of maximum running speed)
• Sprint 50 meters (about 80% of maximum running speed)
• Walk 50 meters
• Repeat for 30 minutes

The distances, times, frequencies, speeds can be manipulated to reflect the athlete's level, time of year, sports played, age and specific sport position. This workout would only be done about 1 day/week in combination with the other training components (power training, agility training, core work, integrated strength training, flexibility, joint stability work etc.)

Mike Caza is Owner and Director of Performance at Premier Sport Conditioning in Twinsburg, Ohio. Mike is the creator of Breakthrough Vertical Jump Training, a complete 12 week program designed to help coaches, athletes and trainers enhance vertical jumping ability in volleyball, basketball, football and track and field athletes. Mike was himself a successful world class high jumper and member of the Canadian National track & field team having jumped 7'5 which measures 18 inches over his standing height of 5'11. For more information on the Breakthrough Vertical Jump Training program, visit www.mikecaza.com or call (330) 487-0810.

Purchase the DVD only $39.95

Download version only $29.95