Last Updated on January 13, 2017 by Jimson Lee
I was watching a great YouTube video with Coach Ron McKeefery interviewing Dr. Michael Yessis. You can fast forward to 3:45 and get to the meat of the interview.
Dr. Michael Yessis received his Ph.D. from the University of Southern California and his B.S. and M.S. from City University of New York. He is president of Sports Training, Inc., a diverse sports and fitness company. Dr. Yessis is also Professor Emeritus at California State University, Fullerton, where he was a multi-sports specialist in biomechanics (technique analysis) and sports conditioning and training.
I was interested in this video because it was Dr. Yessis’ research that introduced me to the delayed squat way back in 1987.
The Delayed Squat
You can thank Michael Yessis and the Secrets of Soviet Sports Fitness and Training
for making Dynamic Isometrics popular. Back then, he described the “delayed squat” where you do several “stops” before the explosive concentric phase.
For weight numbers, they recommend 60-70% of the one RM squat with only 2 or 3 reps. (see my chart on calculating 1RM and Weight Percentages as well as Weight Training, Reps, Intensity and Benefits)
For a Primer, read my October post on Weight Training: Strength, Muscle Mass, and Endurance
To perform the delayed squat:
- slowly descend by bending hips and knees until there is a 160° angle in the knee joints, and hold this position for 3-4 seconds.
- Lower with the same controlled speed until there is a 145° angle in the knee joint, and hold again for 3-4 seconds.
- Again lower to 115°, hold 3-4 seconds,
- and then finally to 90° and hold again.
- Rise in an explosive push, if you can!
As you can see, the whole movement takes 12-16 seconds. This method develops explosive power out of a static position.
Another study came from Weineck 2004 and they suggests 6 sets 6 repetitions using 60-70% of the one repetition maximum, but I think that is overkill. If you are going to do 6×6, I recommend 5×5.
Delayed Squat and Sprinting Applications
I like bench press for 2 reasons: bragging rights, and holding my arms steady in the SET position.
For sprinters and developing leg power and strength, you can use angles of 129 and 95 degrees, since those are the numbers coming out of the blocks “SET” position. Even back in 2007, Ralph Mann suggested you train at those angles with the force-velocity considerations.
Optimal theoretical starting “set” position. Illustration by Derek Hansen of Running Mechanics.
So Dynamic Isometrics for sprinters would look like this (adjust your weights and reps accordingly):
- Using a squat rack, lift the bar off the rack.
- Lower to 129°, hold 3-4 seconds,
- Lower to 95° and hold again 3-4 seconds,
- Rise in an explosive push
Today, we squat to parallel AND squat PAST parallel (i.e. what I call full squats) to ensure adequate hamstring involvement. (see the series on hamstring pulls)
Here is another isometric lift I found useful. It is good for building strength at very specific knee angles. I Try to keep my athletes front knee angle at either 90-95 degrees if we are focusing on block starts, or at slightly greater knee angles if we are focusing on pushing through the first 10m.
http://www.stack.com/2011/03/02/exercise-of-the-week-isometric-deadlift/
Jimson,
A modification to that is one could stagger their squat stance to more closer replicate the foot spacing in the blocks. However, that makes it difficult if not impossible to descend to 1/2 squat depth (parallel) without lifting the heel of the back foot off the ground, causing a less stable base of support and uneven load distribution.