Week 11. Pure Strength & Speed Training – The Science of Power

Maximum Strength vs Contraction Speed

Classic power lifts do not maximize explosive ability because moving very heavy weight reduces contraction speed. Oppositely to power lifters, Usain Bolt maximizes his contraction speeds and velocity running, which requires about 30% of the force produced from the hamstrings in a 1-rep max squat or dead lift.

Squats and dead lifts do not build explosive quick twitch strength; they build maximal tension, which makes a person ‘slow and plodding’ – especially if they already lack quick twitch fibers. Thus, power lifts help you strengthen hamstrings, but do not help you create explosiveness from the hamstrings, which you need for sprinting. 

The next section shows how to develop both strength and contraction speed using weights.

There are three components for developing power:

1. Strength; 2. Contraction Speed; and 3. Force Absorption – shown in this Video

To maximize explosiveness, you must correctly train the limited number of quick twitch fibers you possess.

• “Like trains like”. To develop and maintain explosiveness you must train explosively.
• Heavy weights prohibit speed, and therefore prohibits explosiveness.

Performing plyometric exercises maximize contraction speeds.

• In classic plyometric exercises, a ‘speedy drop’ onto your feet from a height instantly “loads the hamstrings”. Hamstrings absorb the energy while dropping into a squat or lunge position, as shown in the video link above.
• Plyometrics activate the stretch reflex, which makes the hamstring contract explosively – involuntarily.

These videos show the stretch reflex in action:

Spud Webb video.

Plyometrics in Olympic action

Good surface vs. bad surface for plyometrics. (first the bad in the video).

Summary

Landing on the ground from above the floor increases the reactive force driven back up through your legs. The hamstrings absorb the force. And under the sudden increased tension in their ‘stretch position’ – the hamstrings could rip – but they don’t – they protect themselves by reflexively contracting.

The faster and harder the drop onto your feet – the more forcefully and quicker the hamstrings react (contract) to prevent themselves from ripping.  If you time your ‘conscious activation’ of your hamstrings with the moment the hamstrings ‘twitch’ after you drop from a height – you will rebound/jump higher.

You should never add weight onto your back to do plyometrics. Dropping from a height creates the resistance. Doing jump squats is a stupid and unsafe way to create a speedy drop. They’re a great way to wreck your spine and knees.

High Jump Experiment in Fitness Lab

Part 1. Try jumping as high up as possible from the floor. The starting position is with only a very slight bend in knees, but do not drop down from the starting position.

Part 2. Repeat Part 1. But first drop down suddenly from the starting position into a deeper squat position and then jump.

• The latter is what you would have done without thinking if I had asked you, “Jump as high as possible”.
  

By dropping into a squat position quickly, you ‘stretched’ the hamstring by surprise. This puts it into a ‘reactive position’ and makes it contract more explosively – as seen in the jumping videos above.

Part 3: Plyometric Jump From a Height Above the Floor. Drop from a box onto the floor and then jump as high as possible after absorbing the force in the squat position.

• The drop itself produces ‘increased weight’ as the hamstrings absorbs force.
• Then the hamstring will in turn contract even more forcefully than if you drop from standing position.

The keys to controlling and playing with power is knowing how your body transfers and redirects the force and energy relative to:

• The hardness and firmness of the surface you stand on
• Grounding your feet
• Hip rotation and follow through

Compare Force Transmission Between Hard & Soft Surfaces

The greatest amount of force an athlete can redirect – either into their own body motion such as sprinting or into object when striking a baseball or jaw of an opponent – occurs when the feet are grounded on a hard surface.

• When we push hard on the ground (or strike an object), the ground imparts an equal amount of force instantly back up through our skeleton.

• In sports, we transfer force ‘best’ – or most forcefully – when feet are grounded on a hard surface. This applies to pitching off the hard rubber on a mound, striking in boxing, hitting baseballs or golf balls, or stopping a running back cold stone still with a vicious tackle.

An unstable or squishy surface such as a bosu ball weakens the powerful jolt of a strong ‘push off’ because transfer of force is scattered throughout the ball in various directions rather than in the line you intend to direct the force. In short, the energy ‘spreads out’ within the system – not out of it.

• Performing on a hard solid surface is a must for transferring muscle power into motion in any sport.

There are two primary but polar opposite ways to direct energy out of your body:

1. Striking and Follow Through (to drive an object): The goal is to maximally drive an object or your body as fast and far as possible – when striking anything -e.g. the ground with feet when sprinting, a person, or an object like a golf ball.

2. Strike but Pull the Punch at the Point of Contact: Transfer energy into the object so it explodes within the object. The goal is not to drive it with a follow through – but to dissipate the energy within the object and destroy it explosively within.

Striking to drive an object: Demands following through with your motion, while timing rotating the hips as you firmly ground your back foot. Examples of athletes whose injuries prevented maximal striking power:

• Once Bo Jackson dislocated his femur/hip – he could no longer drive the ball. (Hitting a baseball)
• Same with Joe Mauer; in 2014 his left knee soreness and weak legs prevented him from grounded his back leg firmly and his hitting ability diminished.

Transfer energy into the object so it explodes within the object. Example:

• ‘Spider web’ a windshield or stop someone’s heart by pulling the punch.
• Special commentary by Bruce Lee.  Lee on how to cause energy to explode within an object.

COMPARE:  Good surface vs. bad surface for plyometrics. (first the bad in the video)

Questions:

1. Pushing off which one (squishy ball or ground) dissipates energy?
2. Which one allows you to maximize the force through your legs and skeletal system in order to generate more force and power into throwing a fastball?
3. What are the physical keys for the powerful 1-inch punch popularized by Bruce Lee?

Demonstration: Neural Recruitment vs Reps Exhaustion

Demonstration: Instant Strength Through Power of the Mind

Demonstration: Hand Clasp

Muscles create the greatest tension when they are half contracted. The demonstration in class makes understanding this graph easy.

• Fully extended or stretched muscles can’t generate high forces and neither can fully contracted muscles.
• Special video: excerpt from an ESPN 30×30:  In the Heads of Champion Olympic 100m sprinters.

Experiment in Fitness Lab

It is possible to gauge the level of tension – not just in muscles, but also tendons.

• In lab, each of you will experience feeling tension in a tendon.

• Based on the technique I show you to feel a tendon, I will ask you to imagine dropping into the position quickly and then trying to instantly reverse direction – as in a plyometric. This is what your hamstrings experience when drop from a height into a squat position. This is why hamstrings often tear during sprinting. Just the thought of it is frightening.

Before doing exercises that require create ‘snap-like’ explosive power – it’s wise to learn how to feel tension in a tendon. This provides deep experiential insight into how muscles and tendons generate tension.