by: Kelly Baggett
It's an excellent way to organize training. The basic tenet is to alternate high intensity days with low itnensity days so that there's always 48 hours rest between high intensity days. As I'll explain in a minute, I feel it's particularly effective the more lifting an athlete does. This makes it particularly effective for bodybuilders, powerlifters and the like. Having said that, I feel when taken as gospel it's a bit restrictive and could use some clarification. Here's how I would adjust it. First lets give a few examples as to what constitutes "high intensity" and "low intensity" respectively.
High Intensity
1. strength work (anything above 80% +of 1rm for lower body and "whole body" movements such as deadlifts, cleans etc.)
2. maximum effort bodybuilding work (mainly lower body)
3. maximum speed work with full recovery between reps
4. maximum effort plyometric work
5. maximum effort agility and deceleration work
6. maximum effort conditioning work (ie. Timed max effort intervals)
7. martial arts or boxing fighting, sparring, or heavy bag
9. any activity performed with heightened and competitive emotional intensity (competitions)
10. any activity performed under the influence of artificial stimulants
(ephedrine, various energizing supplements)
11. for advanced athletes - any activity involving PR type performances
Low intensity
1. aerobic work
2. submaximal conditioning work
3. dynamic warmups
4. submaximal bodybuilding or upper body isolation bodybuilding work
5. submaximal speed work
6. easy plyometric work (basic unilateral and bilateral hops etc.)
7. footwork drills
8. jump rope
9. martial arts or boxing kata, mitt work, or shadowboxing
The basic rule is that high intensity activities deplete the central nervous system and it takes 48 hours to repelenish central nervous system reserves. Obviously, muscles can become fatigued locally from activity, yet central fatigue affects your entire human organism. That's why a particularly grueling bout of exercise restricted to one area of your body can leave you performing less then adequately in other parts of your body the next day. It's also why activities performed with heightened mental and emotional intensity, such as a few seconds of activity at a track meet or a PR performance in the weight room, can sometimes leave a person fatigued for days.
The CNS - Your Powerplant
Think of your "central" nervous system just like a central powerplant for an entire city. The CNS is your powerplant and it resides in the middle. The job of a powerplant is to provide electricity to the entire city that it controls. Without enough electricity the city can't operate efficiently. Now, think of your external musculature as the city. Your central powerplant has to provide the electricity for your muscles and there's only has so much available energy. Every time you perform high intensity activities you use up available electricity from your powerplant. Since you don't have the option of buying a bigger powerplant, you have to organize your training in such a way that your powerplant does not become overextended. Anytime you stress the capacity of your powerplant via engaging in high intensity training, you stress the powerplant and have to let it build back it's energy reserves.
Your Powerplant Needs Time To Recharge
Now, it takes your central nervous system approximately 48 hours to recover from those high intensity activities. The basic tenet is that to foster consistent performance and recovery, high intensity activities should be placed on the same days with other high intensity activites and those "high intensity days" should be alternated with "low intensity" days.
Therefore, in a weekly schedule you might have strength work, plyometrics, and maximum speed work placed on mon, wed, and friday while aerobic and conditioning work would be placed on tuesday thursday.
OK, my personal feeling is that abiding 100% by this rule is much more important when the high intensity elements provoke muscle injury. What is muscle injury? Nothing more then protein breakdown caused by eccentric contractions. What mainly stimulates it? Strength and bodybuilding work. That doesn't mean the other high intensity elements such as sprinting, plyometrics, and agility work can't stimulate muscle injury because they can, particularly when really pushing it to the maximum or setting PRs - this is particularly true the more advanced the athlete is, (which is why more advanced athletes get more out of this type of setup then beginners). For example, agility and deceleration work are known as 2 of the elements that "beat people up" the most. Yet it should be no surprise that this (muscle injury) occurs more with weight training when one of the basic goals of most weight training is muscle breakdown. when a muscle is injured (damaged), inflammatory messengers are stimulated which spread and dock in areas throughout the body, including the brain. These messengers really promote the systemic fatigue and prolonged recovery time that most people refer to when they talk about "CNS" fatigue. Muscle injury to the human CNS is kind've like a tree falling on a power line - It causes transformers to blow out and a city's power supply is disrupted.
So, in my opinion the main point to pay attention to when organizing your training is to make sure you always follow up high demanding "muscle injury" type days with a lower intensity day. Most people can tolerate multiple consecutive days of "high intensity" activities so long as they pay attention to the stress induced in those sessions and hard weight training days are followed by easier days. Therefore, provided you pay attention to the level of emotional intensity you perform under, and physicaal stress (soreness) generated by your non weight training high intensity elements, it's normally Ok to perform plyometrics one day and sprinting the next, maximum speed one day and lift the next, or linear speed and plyo one day and agility the next, -or any combination thereof. But as soon as you throw lifting and strength work into the equation everything needs to be looked at a little more closely. If you have a hard lifting session one day and try to sprint or do anything else high intensity the next, don't expect to be very successful at it simply because that lifting is probably going to provoke more muscle injury.
I hope that makes sense.