So I've been studying to get certified as a trainer and been doing a final review of the textbook, wanted to share some points I thought were important from the chapter on speed and agility training
It's mostly more well known, pretty straight forward or not super practical stuff, but I have added a "***" to stuff that I found of particular interest
GCT ranges:
-Maximal contraction for a lift (300+ ms)
-Agility (230 - 250 ms)
-Change of Direction (440 - 722 ms)
-Acceleration (170-200 ms)
---Second step averages (novice - 223 ms, elite - 123 ms)
-Top Speed (90-110 ms)
--- averages (novice - 101 ms, elite - 87ms)
Misc training information:
Strength Training - one adaption is increased neural drive - faster rate and amplitude of impulses being sent from nervous system to target muscles. Improvements mean an increased rate at which action potentials occur
Plyometric Training - enhances excitability of high threshold motor units
The Stretch Reflex (SSC)
-Performing a movement with a stretch reflex is a completely separate capability from max strength.
-Acute adaptions of the SSC - increase efficiency and impulse via elastic energy use
-Chronic adaptions of SSC - upregulate muscle stiffness and enhance activation
-Plyometrics and heavy resistance training (for both: emphasize technique, brief work bouts, high rest) can both train the SSC
*** Adaptions and MU recruitment patterns for an eccentric contraction are different than those for concentric ones. Adaptions from eccentric training appear to be specific to the velocity of eccentric loading.
Speed
"The amount of vertical force applied to the ground during stance phase may be the most critical component of improving speed. In addition, these forces must be applied to the ground in the shortest period possible."
*** Elite sprinters manage to generate high levels of vertical force quickly, during the first half of a ground contact. Nonelite sprinters tend to have a more gradual buildup of force generation.
-Why? One study suggests that there is an optimized knee height at max flexion during swing phase that then allows an efficient force application during the GCT that follows.
-Stride length and stride frequency are slightly longer and slightly faster during top speed in higher level sprinters.
-Elite sprinters reset of the swing leg takes about the same time as non-elite.
-emphasize merging max strength and speed-strength
-Especially important are to display forces and velocities similar to those found in sprinting: hang clean, snatch, thigh variations - offer most benefit to rate coding, firing frequency and type II fibers
Change of Direction and Agility
shown to improve with:
-low center of mass height
-increased hip extension velocity
-increased braking and propulsive impulses
-increased knee flexion when entering CoD
-decreased trunk angular displacement entering CoD
-increased lateral trunk tilt (during 180 CoD's)
psychological components:
-anticipation
-visual scanning
-pattern recognition
-decision making accuracy and speed
cues for CoD:
braking:
-control trunk during deceleration
-reorient trunk to CoD angle
-body lean, alignment of body
-enter and exit with lower center of mass
leg action:
-avoid stiff-legged force absorption style
***-focusing on cues related to ground and not body parts has been shown to improve CoD
-well rounded approach to training, including isometric, dynamic and in particular eccentric strength is recommended
*** -training that allows the neuromuscular system to adapt to rate of loading during the braking phase must be specifically trained with high velocity eccentric contractions: drop landings, loaded jump landings, catch of power clean and snatch
-development of agility with random programming and only sport-specific methods such as games has been shown to be less effective
