I would bet money that they have a high level of relative body strength, a low body fat level and a high rate of force development. (dieselcrew.com)
Stiffer springs have greater rates of force development when included in a system, because they transmit forces quickly from one end to the other. (strengthandconditioningresearch.com)
The observations of altered rates of force development and relaxation during maximal twitch contractions suggested an alteration in calcium - related markers in the muscles from IL - 15Rα — KO mice. (jci.org)