Two types of breakdown occur from weight training that are hugely important to athletes. One is muscle breakdown, which we are all familiar with. This is the muscle soreness, swelling and pain that we all get in the hours and days after a good workout, often referred to as DOMS (Delayed Onset Muscle Soreness). Muscle breakdown and muscle trauma are ultimately what is responsible for muscle growth and improvement. Once the muscle is damaged after an intense workout, the body responds by building it up better than it was before in order to better tolerate such workouts in the future. Muscle damage is an essential part of growth and is, essentially, necessary. Central Nervous System (CNS) damage, on the other hand, is much more ominous. The central nervous system is responsible for everything muscles do. When you want to do an arm curl, your brain sends a signal to your bicep to contract. When the nervous system is damaged and not operating at its best, it can’t send this signal as strongly, and subsequently the muscle doesn’t contract with as much force. Think of the CNS as the electrical grid for a city. If it is overloaded, less power is available to everyone, not just the area of highest use. CNS damage is essentially when the entire central nervous system gets depressed as a result of overtraining. As opposed to muscle damage, which is isolated to the particular muscles it effects, CNS damage affects then entire body. It deteriorates brain to muscle signaling, making the force and exertion of every muscle decline substantially. CNS fatigue comes along with a number of neurochemical changes as well. Serotonin and dopamine levels are critically effected resulting in not only physical fatigue, but mental feelings of overexertion as well. Of particular note about CNS fatigue is that is it cumulative, in that damage can accumulate over a period of days, and it is also very slow to recover. In fact, it can take the body six times longer to recover from CNS damage than muscle damage.
So how do you know if you are experiencing CNS fatigue? Once you understand what it is, the indicators that you may have it become very obvious:
Overall muscle weakness: Breaking down the CNS means that the signal to the muscles becomes weaker, and as such, even a fresh muscle is unable to perform that well. If you did xx weight for 15 reps last week, then allowed your muscle to recover, but this week you are only able to get 12 reps the chances are your CNS is in need of repair.
General fatigue: One of the easiest indicators of CNS fatigue is an overall lack of motivation. You may think it is all in your head, or you need to “get pumped up” but in reality your body may be telling you something. CNS fatigue comes along with a downregulation in dopamine, which is responsible for feelings of well-being as well as perceived fatigue. A decrease in dopamine means a decrease in performance and motivation.
Overall body pain: This is a general feeling of exertion. Things that are normally fairly easy physically seem to be much harder and hurt to do them. Body aches become common and even the warmup set at the gym hurts.
There are quantifiable ways to determine if you are experiencing CNS fatigue as well. One excellent way is to use a hand grip dynamometer. This is a simple device that measures the force with which you are able to squeeze with your hands. The first step is to establish a baseline by squeezing the dynamometer when you haven’t trained in a few days and your CNS is known to be fresh. Record these results. Then any time you wish to measure if you are experiencing CNS fatigue, measure your grip strength in exactly the same way at the same time of the day. If your results are more than five pounds down or so from baseline, you are not fully recovered.
So what can be done to repair a damaged central nervous system? As with any injury, the most prevalent way is to give it time, but here are a few steps you can take to get a quick recover as quickly as possible:
Rest and sleep: This is first and foremost. Particularly with neurological conditions, deep REM sleep and plenty of rest are when the body will recover the most. Take some extra time to relax and designate an extra hour or so to sleep each night. Quality of sleep is the #1 factor in CNS recovery. Serotonin and GABA levels are greatly influence by good sleep which will lead to great recovery.
Avoid stress: Easy to say right? But as it turns out CNS fatigue comes from all types of stress, not just that of workouts. Try avoiding potentially stressful situations for a couple days to give yourself some time to recover. This includes time off from the gym unfortunately.
Light cardio or low impact activity: While high impact workouts should be limited or avoided altogether, light cardio to accelerate blood flow can actually expedite the healing process. Try light walking or even low intensity stretching to facilitate this.
Inositol and Magnesium L-Threonate: Researchers have found magnesium-L-threonate can rebuild ruptured synapses, and restores the degraded neuronal connections common in extreme neurological conditions. Likewise, Inositol can work wonders to restore healthy neurotransmitters and CNS signaling pathways. Getting a steady intake of these two nutrients can not only repair a broken down CNS, but can prevent a healthy one from being overtaxed.
Overall, a damaged or fatigued CNS system can completely shut down your ability to improve. Becoming conscious of when it is damaged and in need of repair, and taking the proper steps to allow it to heal will make the difference between big growth and big frustration in your training.