By Will Swann, CSCS, USAW
The central nervous system (CNS) is the primary engine for performance. A fatigued nervous system is unable to recruit high level motor units and coordinate muscular actions as efficiently, resulting in decreased power and limited performance. If you want to build the highest possible amount of speed, strength and power for rugby, you need to train the nervous system as your highest priority. In this article you’re going to learn the most efficient and effective way to do exactly that, so pay attention!
Most people tend to focus on the adaptations occurring at the muscular level in their training: hypertrophy. They account for the damage training does to joints, tendons, and muscles, but rarely consider the toll that the nervous system takes when performing heavy weight training and explosive movements. Because the central nervous system typically takes longer to recover than muscular fatigue, an athlete might “feel” recovered and have no residual muscle soreness following a session, but the nervous system will still be in a state of fatigue. And remember: the CNS is the driver of speed, strength and power. If the CNS is fatigued, you’re underperforming. You cannot overstate the importance of the CNS in training, and you must account for it.
Enter the high-low training system
Charlie Francis, a coach best known for training Canadian sprinter Ben Johnson, was one of the first coaches to understand the importance of neural recovery and developed the high/ low CNS training model with his athletes. While this training method was initially used for sprint training, the fundamental concepts can be applied to any strength/ power sport, including rugby.
Rather than thinking about training different muscles, and separating your training so that your muscles are recovered, think of the body as having a finite amount of neural training reserves, kind of like juice in a battery. For example, maximally taxing the nervous system from sprinting and jumping one day will negatively affect the ability to maximally recruit force squatting or benching the next because you’ve used up your “juice” for 48-72 hours and need to recharge your battery. This means if you try to perform maximal speed, strength or power sessions on consecutive days, you’re significantly underperforming at best and getting hurt at worst.
Any and all neurally taxing efforts must be accounted for in training. The Charlie Francis model split up training into days categorized by “high” and “low” CNS activity. By categorizing training sessions and practices in this way, you are able to train maximal speed, strength and power activities when you have a full “battery” and deliver a high intensity training stimulus to the CNS. This means you make faster progress and reduce your risk of injuries. On the low training days you switch your focus to activities which are far less stressful to the CNS. You can and will still progress, but you will allow the CNS to recover whilst doing so because low day activities are low enough to not interrupt recovery.
Identifying high and low CNS activities
Generally speaking, high intensity work are those which require high speed and/or force (the two amplifiers of CNS fatigue). These activities must be separated by a window of 48-72 hours or we risk accumulating neural fatigue, harming performance and increasing injuries. These movement. High intensity activities:
Sprints and bounds
Weights >80% of 1RM
Explosive med ball throws
Although maximal conditioning and contact practices are generally lower force and speed than sprint work, they entail a high degree of fatigue and psychological stress which have to be recovered from and which generally cannot be performed on consecutive days, so they are included here.
Low intensity movements are essentially the opposite: low force, low speed, low stress, low fatigue. Whilst being good training adaptations in their own right, training certain adaptations on low days are crucial. Adaptations like capillarisation, mitochondrial density and increasing cellular substrates like glycogen and creatine phosphate will also enhance performance during and recovery following high day training. Low day activities include:
Med ball circuits
Note: Charlie Francis was adamant on excluding moderate intensity training activities or runs runs (76-94%) out of his sprint training. The problem with these activities is that they aren’t intense enough to stimulate the CNS, but are too intense to recover from within 24 hours, so we essentially get all of the fatigue with none of the benefit. Depending on the training phase, medium intensity movements may be necessary for development of some rugby skills. However remember this is not going to increase maximal speed, strength or power and any work deemed medium intensity should be considered high intensity to ensure adequate recovery.
Incorporating high-low training into rugby
Below are two sample weekly pre-season training splits, incorporating either 2 or 3 high training days per week (chart 1). In each example the high and low intensity training activities are grouped together on the same day so as to provide the central nervous system with alternating days of stimulation and recovery respectively.
These training splits focus on increasing multiple fitness characteristics at the same time as is typically necessary in rugby. Using this template you will want to alter the volume of the activities you are performing as your objectives progress. For example a higher volume of weight work in early pre-season, and a higher volume of sprint work as the season approaches.
2 high day training week
3 high day training week
Caution must be used, however, so that conflicting training goals are not incorporated at the same time because adaptations that compete for the same reserves will result in blunted adaptation and sub optimal performance. The following table shows a list of compatible training goals:
Note that rugby training sessions also have to be accounted for and should reflect the high or low training theme for the day. On high days should entail higher force, speed, contact and fatigue e.g. opposed drills, contact work etc. Conversely low day training sessions will typically be easier with longer rest periods e.g. skill focussed sessions, walk throughs, unopposed work etc.
In this example of a training split for in-season you can see that the same high-low format of work is present, but that the match (a maximal activity) occupies one of the high days. Working backwards in 48 hour intervals, this gives us Thursday and Tuesday as our high training days. Tuesday will generally be the more intense of these training days as there is longer to recover before a match. By process of elimination we are left with Monday, Wednesday and Friday as low activity training days, which usually take the form of low intensity training, a day off and the Captain’s run respectively.
In-season training week
An athlete has a limited amount of time and energy to spend on improving athletic performance. Ensuring that the central nervous system is fully recharged will enable that athlete to perform at a maximal level, whether it is on the pitch or in the weight room. Implementing a high/ low training template into your program is one option that can help increase the recovery status of your players, improve multiple performance characteristics at once, and ensure that effort is at a high enough level to elicit adaptations. Things to remember with a high/ lo training split:
A minimum of 48 hours is required between high intensity effort days
Consider moderate intensity practice and speed work to be the same as high intensity
Only place an emphasis on improving fitness qualities that are compatible with one another, and put your high activities together on the same day, not consecutive days .
Remember to account for the intensity levels of practice and games. Make them fit your high-low template.
Low intensity practices can be used to work on tactical and technical skills as well as fuel recovery without interrupting the recovery of the CNS