Pillar 4 of our 5 part series on explosive power by @strong_by_science. .
Rate of force development is calculated by the amount of force one can produce divided by the time it takes to produce that force. .
If you have the ability to produce a large amount of force without limitations on time (absolute force), theoretically you will be able to produce a larger amount of force in a given period of time (rate of force development). Ex: 25% of 100lbs = 25lbs, but 25% of 200 = 50lbs. The person with a larger absolute force will produce a a higher RFD in a time frame. However, a large RFD can also be achieved through being able to express a large percentage of absolute strength. So, if the weaker athlete can produce 75% of their absolute strength, they will produce 75% of 100 = 75lbs and out perform the stronger athlete who can only produce 25% of their absolute force. In a perfect world you would have both a large absolute strength and be able to express a large percentage of absolute strength. .
Training RFD is normally done through a mixture of plyometrics, slow velocity strength training, and high velocity strength training. It is its own quality, but it can often be trained in conjunction with other qualities. Some coaches may use static start movements to remove the usage of the strength shortening cycle. In theory, by removing the eccentric portion, you are putting all of your force development on the contractile properties of the muscle. For a lack of better words, it emphasizes concentric rate of force development. .
Komi, P. V. (2003). Strength and Power in Sport, Second Edition (ed P. V. Komi), Blackwell Science Ltd, Oxford, UK. .
Cormie P et al. Developing maximal neuromuscular power. Sports Medicine 41(2). February 2011. .
Newton, R. U., Kraemer, W. J. (1994). Developing explossive muscle power: implications for a mixed methods training strategy. Strength and Conditioning, October(May 2016), 20–31.