Tuesday, April 16, 2013

High Tension vs High Speed Movements






High Tension vs High speed movements

To better understand the reasoning for the various training methods and their focus think of it this way.  Methods that improve maximal force tend to be high tension/long duration movements. That is, the weights are generally heavy, our force output is high and the muscle fibers are subjected to a fairly long duration of tension due to the load.   When you execute a maximal squat it is impossible to move the weight at a lightning rate of speed no matter how hard and how fast you push.  The muscle cells are under tension for a longer period of time, which improves their maximal force capacities.

In contrast, an exercise such as a jump squat is a high tension/low duration movement. The force output is high, but because of the reduced loading and the speed at which the exercise occurs, the duration of this tension is much shorter.  This doesnt do a whole lot to improve maximal force output yet it does do a great job at improving maximal rate of force development or the speed at which you can build up to maximum force!


Now consider a depth jump.  When stepping off a high box and impacting the ground at the moment of impact the force output is very, very high.  In fact, the amount of force is up to 9 times your bodyweight or more! At first glance you might think this may be good for increasing maximal force production and it does provide value in this regard, yet the duration is also very, very short. The depth jump, due to the quick stretching of the muscles and tendons and subsequent powerful contraction, trains the stretch-shortening cycle.  This is something that heavy load weight training and even lighter load/high speed power training do not do quite as well.  Likewise, the depth-jump, although great for training the stretch shortening cycle and reactive strength, is not as good as weight training at boosting maximal force capacity.  Also, due to its reliance on the quick stretch-shortening cycle, which is largely an involuntary reaction, this training method is not as good as some others at improving the rate of force development. Pure rate of force development training is purely voluntary and “cheating bouncing or trying to get a reflexive reaction actually takes away from its training effect.

Now, to see how these training methods all fit together if you were to take out a sheet of paper and to the far left hand side writeSquat, and to the far right hand side write Depth-Jump, those exercises are at the 2 extremes for power training. The squat for pure voluntary force and the depth jump for involuntary force.  They are both necessary but do not train the same qualities. One is high tension/long duration and one is high tension/short duration. One is dependent on muscular strength and one is more dependent on tendon strength.

Next, if we were to progress from left to right from high tension/long duration to high tension/short duration there are a lot of middle ground training techniques to fill in the big gap between squats and depth jumps.  These would include for example: squats progressing to lighter weight explosive squats, weighted jump squats, 1 and 2-legged skips, hops, and jumps, jumping on or over objects, bounding activities, and finally, drop jumps and depth jumps.

The following table categorizes the different training methods as either targeting maximum force, rate of force development, or stretch-shortening cycle/reactive strength.

Maximum Force and
Strength (high
tension-long duration)
Rate of Force Development (high
tension-short duration)
Reactive Strength
(very high tension- very short duration)
Any strength training
movement using 75% or more max weight in that particular movement
Any strength training movement using
less than 60% maximum weight done with maximum speed and force along with little if any prior countermovement.
Any rhythmic
exercise heavily involving the stretch-shortening cycle
Squats
Weighted jump Squats and speed Squats
especially those done with a pause before the contraction
Jumps back and
forth over obstacle
Deadlifts
Stationary up” and out” variety
Hurdle jumps




plyometrics

Lunges
On-box jumps
Depth jumps
Romanian Deadlifts
Standing broad jumps
Shock jumps (depth
drops)
Glute-Ham raise
1-leg step up jumps
One leg speed hops
Leg-curl
Un-weighted jump squats
Jumping off of 1
leg for height
Calf raise
Vertical jump from dead stop crouched
position
Rhythmic rim
jumps

Of course, no single exercise is usually going to be purely a maximum strength, rate of force development, or reactive strength exercise.  With most exercise variations there is generally going to be some overlap between the different qualities.  However, I wanted to make the point that certain exercises do a better job at targeting different qualities.

The following table summarizes the effects different types of training have on different strength qualities.

Strength Quality
Heavy
Weight
Training
Lighter load explosive
weight training (jump squats) and other explosive bodyweight exercises
Plyometric drills
like shock jumps and depth jumps
Maximum Strength
Excellent
Fair
Fair to Good
Maximum Rate of
Force Development
Good
Excellent
Fair
Stretch- shortening
cycle/Reactive strength
Poor
Good
Excellent
Jumping skill and
muscle coordination
Poor
Good
Excellent



You know you need optimal levels of all the 3 qualities (maximum strength, rate of force development, and plyometric strength) to really improve your vertical.