The rate of force development(RFD) is one of the most misunderstood measures of physiology for both researchers and coaches. I spent last week combing through the research, and there was very little congruence amongst authors. Some defined a fast RFD contraction as ≤250Ms and slow as ≥250Ms, while others said 50-75Ms was fast. Some related RFD to the stretch shortening cycle and some to overcoming inertia.
However, here is what I was able to come away with. The first 100Ms of a contraction rely heavily on neural properties like rate coding, high threshold motor unit recruitment, and the stretch shortening cycle(SSC) and certain elastic properties found within the muscle-tendon unit(MTU). Longer contraction rates longer than 100Ms rely more heavily on maximum strength.
Here’s the takeaway: neural properties, elastic elements of the MTU, and maximum force production properties are important at any rate, but one or more of these physiological components are more important depending on the rate of contraction. Let me say this in an easier way to understand with an example. In the countermovement jump, the first 100Ms of the jump relies more heavily on neural and elastic components, and then maximum force production becomes more prevalent during the stages after the first 100Ms. The SSC of a typical countermovement jump lasts around 500Ms. I would also like to add that RFD is important for the sport of Powerlifting as well because improved RFD means that high threshold motor units are recruited faster and improved elasticity means more explosion out of the hole with back squats.
The back squat and deadlift are known to elicit adaptations leading to neural, elasticity, and muscular improvements known to improve the RFD including:
No wonder strength coaches will fight over the importance of the back squat and deadlift to improve jumping and sprinting times especially in the first years of an athlete’s development. The best part is that the powerlifts can lead to even greater improvements in RFD depending on how you use them. Here are some examples:
The moral of the story
Every strength coach on the planet has heard a parent or athlete say that they didn’t want to get big, strong and slow, which most of us laugh at. However, there is a point that the Big 3(squat, bench, and deadlift) might lead to slower RFD if taken to the extreme like trying to back squat 900 pounds. However, for the masses, the Big 3 will lead to RFD improvements equalling higher vertical leaps and faster sprint times. The magnitude of improvements will depend on how those movements are applied especially for the more advanced athlete.
P.S. If you want to learn the latest in the world of Powerlifting and application of the Squat, Bench, and Deadlift for athletic performance, don’t forget Stronger Experts is planning their inaugural clinic at Rise Indoor Sports in Advance, NC right outside of Winston-Salem and one hour north of Charlotte and Streaming LIVE around the globe. We are going to discuss the sport of, you guessed it, Powerlifting:
⇒ Powerlifting: The Age of Science
I promise that you will learn new truths about the Big 3 Lifts that we all love. The information will apply to powerlifting, strength and conditioning, and even weightlifting, so get signed up and come hang out. AEL, Accommodating Resistance, and VBT will definitely be some of the topics along with RFD.
Fast track your carreer and learn from some of the best experts in Strength and Conditioning.