Your fast twitch fibers are important to maintain, they are what help you respond to a sudden change in your walking surface, helping to prevent falls, the leading medical issue as a person ages. One of the ways to test your fast twitch fibers is by jumping.
it is important to practice your jump technique by jumping over a board, line, or book. Make sure both feet travel together, use your arms and legs to propel you over the object landing on both feet at the same time, knees bent.
Stand with two feet together in front of a raised platform that is about 6 inches or 15 cm off the ground. Use your arms and legs to propel yourself up onto the raised platform, landing both feet at the same time, knees bent.