Explained
Eccentric braking is the rate at which one can go from peak eccentric velocity to zero velocity (isometric phase). This is an often overlooked aspect of dynamic movements.
The Sympathetic Nervous System: Its Role in Exercise
The Stereotype
The sympathetic nervous system is too often looked down upon. We erroneously associate it with hyperactivation from external psychological stressors and the inability to properly get into a “recovery” state.
Without our SNS, we would never cope with any stressor, period. It’s time we start talking about the SNS with respect, as it plays an integral part in optimal performance.
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Relative Strength Matters
Why Body Weight and Relative Strength Matter
The picture below is a simple mathematical representation of why pounds are not created equal in sport.
In the above theoretical situation, there are two athletes. One weighs 90kg the other 100kg. Let’s assume that they both start from a static position (sitting on a box) and jump straight up into the air. For both athletes, the jump took 1 second to perform (yes very slow) and they both left the ground at 4.4 m/s. Thus, they both jumped the same height. However, the question is, how much more force did the heavier athlete have to create?
Well, the net impulse difference was 44kgs between the athletes, despite only a 10kg difference in weight. Continue reading “Relative Strength Matters”
“The Muscle-Tendon Spring”
MTU
A.V Hill was one of the great sports performance pioneers, whether he knew it or not. One of his many contributions included the 3 element model of the musculoskeletal-tendinous unit (MTU).
In short, it is broken up into 3 regions.
- Contractile element (CE). These are your actively producing contractile structures (myosin and actin).
- Parallel elastic component (PEC). Just kind of a fancy way to say the stuff that surrounds the contractile element, but isn’t actively contracting, making it passive. (The PEC and CE kind of work together. Because the PEC surrounds the CE, when the muscle tightens up, so does the PEC).
- Series elastic component (SEC). This is just the tendon, which if you laid a muscle out on a table, it would be “in series” or basically just an extension of the CE and PEC.
Fast Force
“Fast Force”
The idea that velocity is an independent quality, especially in terms of physics, is a little erroneous. We often, including myself, label exercises as “force” or “velocity” movements. However, such statements are used to simply label the quality we are targeting and not necessarily to identify the underlying mechanism.
Movement occurs from forces acting upon an object; there is no way around it. However, the way we display these forces can vary quite a bit. As noted in the breakdown of F=MA, one can quickly see that in order to improve the magnitude of the movement, and ultimately its velocity, we have to apply more force.
Rigid vs Plastic: balance between the systems
When it comes to your body, you essentially have two systems
On one hand you have a rigid system which is immediately necessary for life. On the other hand you have the plastic system, which is much more dynamic in nature and aids in maintaining the rigid systems.
Due to the fact that rigid systems are immediately necessary for life, they have a small range where disruption can occur. Therefore, any disruptions in the rigid system cause amplified disruptions in the dynamic system.
Because the plastic system supports the rigid, it can handle much larger perturbations (as demonstrated by my squiggly lines).
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Intra- and Intermuscular Coordination
Intramuscular coordination is the firing pattern of fibers within an individual muscle.
For example, prior to a ballistic action, there appears to be a silent period in electrical activity at the local muscle. The thought is that such a silent period is a form of neural inhibition that turns off all motor units to make sure that when the action is about to be performed, non are in a refractory state. Thus, allowing for maximal motor unit activation.
Intermuscular coordination has to do with how muscles fire in coordination with other muscles.
The green arrows suggest that all muscles have acted together in the most efficient way.
Adaptation
What does it mean?
The idea of “general” adaptation is very misleading.
There is no such thing as a “general” adaptation, it is merely a word used to explain an idea we don’t care to specify. For example, people might label the squat, deadlift, and bench as “general” exercises. But if I have three athletes and each performs only one of those exercises, their adaptions will not be the same; All will not have the same “general” response.
Percentage Drop Offs
Plyometrics, Ground Contact Time, Jump Height and Power Monitoring
When performing movements that require reflexive actions such as depth jumps, the ability to monitor jump height and ground contact time is critical.
Reflexive plyometric actions can stimulate near maximal muscle contractions. However, like voluntary contractions, reflexive actions can fatigue.
Small Adjustments: Staggered Stance
Asymmetry in Sport
Jump exercises in training are usually performed in an extremely controlled environment. In addition, they are typically done bilaterally with an attempt to have each foot hit at the same time; a symmetrical stance. There is nothing wrong with this, however, a further progression towards complexity is rarely made.
In action, sport is quite asymmetrical. By no means am I saying all exercises need to be performed just like sport, but variety doesn’t hurt.
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