I run into this all the time…Johnny or Suzy needs faster legs, we have to get their legs moving faster! So the parent has them doing sprints until exhaustion; that in itself can actually slow them down, and I will tell you why.
To generalize this discussion for time purposes….A sprint athlete is primarily using fast twitch muscle fibers. Once you pass the time frame of good sprint times (hint-use a timer) the workout should be over. If the athlete is exhausted and the workout continues, you will dig into the slower more endurance focused type 1 (slow twitch) muscle fibers. If this is a common training practice, you will in-fact be training the body to survive (endure) the workout. Thus slowing the athlete down, not to mention teaching bad form.
The goal here is a better athlete. So lets start with some basic foundational rules:
How high someone can jump, or how fast someone can explode out of the gate/blocks, is directly related to how fast they can apply force to the ground. The same holds true for acceleration-its all about the force! Sounds like we are talking about POWER =Work/Time. So how do we increase or maximize power?
Lets assume we have appropriate foundational core strength (I hate that term/buzz word), ok lets call it the “frame”.
The frame has to be solid, as to not flex or compress, in order to put the most power to the ground. A weak frame would be like a comparison of trying to help your friend push his car to the gas station in a rut filled 5ft deep with Jello. A strong frame is trying to do the same on solid concrete.
The frame is all of the space between the shoulders and hips, and should be solid (concrete), in order for the bottom line (the arms and legs), to be able to produce greater amounts of force, and have less energy loss due to jello:) The four limbs (arms and legs) are securely anchored to this strong foundation (frame) and the joints need both stability and mobility to produce the most power and performance.
When an athlete comes to us for more performance, sometimes they are disappointed at our analysis and prescribed plan of action, because they were expecting it to involve more and heavier work. We can provide a better formula by anchoring and mobilizing the poor performing joint structures and reigniting muscles that have shut down.
That brings us to movement patterns (muscle firing order) and agonist and antagonist muscle synergy. Muscle synergy is when muscle groups work together to coordinate movement. Muscles that oppose one another (agonist and antagonist) can be working together in order for a muscle to perform correctly and also to stabilize that movement. The ability to turn muscles on and how fast we turn them on (and off) is the pure definition of power, and obviously plays a very important role in power development. We need to have the neurology to fire muscles quickly, in the correct order, and turn them off just as fast to maximize power production.
Let’s use the vertical jump as an example: To maximize this movement the athlete drops down quickly and flexes the hips, knees, and ankles right before take-off. This action, if performed correctly, activates the extensors (glutes, hamstrings, calves) like the pre-stretch of a rubber band before shooting it across the room. Specific muscles fire to allow the body to come down fast and opposing muscles fire in the reverse action to jump as high as possible. There is a lot of skill involved in a seemingly non complex movement such as a vertical jump. The specific skill I am referring to is the ability to turn on and shut off motor neurons that are activated within the muscle. The ability to recruit and turn on and off motor units (a measure of motor neurons) is a foundational component to power development. I have the pleasure of working with a neuromuscular therapy technology called ARP Wave (a proprietary electronic device) that can help me determine what muscles are not firing and turn them back on!
Now lets focus on motor unit recruitment and performance training…When we perform traditional isotonic weight training, we are recruiting a specific amount of motor units based on the amount of force needed to lift the weight. And how fast we lift the weight will determine if we recruit fast twitch motor units or slow twitch. Research has shown that an increase in the speed of the contraction will result in a higher level of fast twitch motor unit recruitment. This again results in more power.
I will use a squat or a press motion as an example here:
As we go through a range of motion we go through mechanical advantages and disadvantages at different ranges throughout the movement. We are stronger at certain points and weaker at others. As in a squat or a press, the deeper you go the weaker you are, and the closer to the top of the motion or lockout you are the strongest because you have a greater mechanical advantage. When our muscles are at the mid range of contraction they are at the optimal length to produce the most force. So it seems that this tells us…the best time to have the most resistance is at the top or end of the movement to produce added challenge for producing performance gains. It would not be as productive to add resistance to the weakest part of the lift for performance gains, as fatigue would result in this weaker position and produce premature failure- session over!
This is where the addition of chains and bands come into play to help create accelerated muscle contractions and dynamic strength. This has by far been becoming my favorite type of training as of late- add a band to that movement as part of the progression plan! By applying a chain or band to the bar it allows for lesser tension at the bottom of the movement and greater tension at the top of the movement. This also helps with recruiting the faster motor units we spoke of earlier, as you will be required to use less weight and thus move the bar faster. Another good benefit of the bands and chains are the smaller auxiliary muscles it fires as well to help to train that core, ugh, I mean frame!