A plyometric motion is defined as a quick, explosive eccentric and concentric contraction of a given muscle. For example, when an athlete jumps, the plyometric motion includes an eccentric (stretching) contraction of the athletes gastrocnemius (calf), a quick amortization phase (time of stretch to concentric contraction), and a rapid concentric contraction. The time it takes to go through this entire stretch shortening cycle, is called ground contact time.
If an athlete is looking to improve their vertical jump, improving their ground contact time, and overall force production is of utmost importance. One way to train that ground contact time, is by incorporating plyometric exercises into your training program. These may include box jumps, depth jumps, squat jumps, line hops, even jump rope. If ground contact time is too long, the athlete’s ability to push, accelerate and even jump is going to be compromised.
Shalfawi et al. found that there was a strong correlation between vertical jump height and sprint speed in a study performed with professional basketball players. These results make sense since jumping requires rapid force production in to the ground, similar to sprinting. A previous article done by Wisloff et al., also found a strong correlation between squat strength and vertical jump heht and sprint speed. Strength always plays a role in force production. The only issue would be if strength training alone can improve jump height enough to gain a significant advantage.
If a program is designed around increasing lower body strength and power, one could infer that the athlete should be able to see even greater improvement in their vertical jump height. An article by Fotouros et al. performed a study that found that a program consisting of weight training, Olympic lifting and plyometric exercises elicited the greatest improvement in vertical jump performance compared to programs that soley focused on weight training or plyometric training.
– Dave Robbins
Facility Director at BlueStreak Headquarters
Masters in Exercise Science and Nutrition
Fatouros, Ioannis G.; Jamurtas, Athanasios Z.; Leontsini, D.; Taxildaris, Kyriakos; Aggelousis, N.; Kostopoulos, N.; Buckenmeyer, Philip. Journal of Strength & Conditioning Research: November 2000
Shalfawi, Shaher AI1; Sabbah, Ammar2; Kailani, Ghazi3; Tønnessen, Espen4; Enoksen, Eystein5
Journal of Strength & Conditioning Research: November 2011 – Volume 25 – Issue 11 – pp 3088-3092
Wisløff U, Castagna C, Helgerud J, et al. Strong correlation of maximal squat strength with sprint performance and vertical jump height in elite soccer players. British Journal of Sports Medicine 2004;38:285-288.