Overreaching is one of those difficult areas of strength and conditioning that gets talked about a lot without any clear definitions of what is going on under the surface.
Yet, overreaching is very much simpler than overtraining, which is a complicated medical condition that we know little about.
In fact, overreaching can actually be defined and understood quite quickly, once you understand how recovery works.
Let me explain.
What are overreaching and overtraining?
The standard definitions of overreaching and overtraining are:
- Functional overreaching — a short-term reduction in performance that later leads to improved performance after a taper or a period of rest.
- Non-functional overreaching — a short-term reduction in performance that recovers fully (but does not lead to improved performance), and only after a sustained period of rest.
- Overtraining — a longer-term reduction in performance that recovers fully, but only after a sustained period of rest lasting longer than 2 months.
Functional and non-functional overreaching are also usually seen as non-pathological states, while overtraining is a pathological condition requiring medical diagnosis.
Overtraining is a complex syndrome involving multiple features, many of which may be caused by chronic inflammation. It has been associated with parasympathetic disturbances (fatigue, slower-than-normal heart rate, loss of motivation) as well as sympathetic disturbances (insomnia, irritability, agitation, faster-than-normal heart rate, hypertension, and restlessness). Additional effects include weight loss, loss of focus, muscle soreness, anxiety, and poor sleep quality.
In contrast, overreaching is very much simpler.
What causes overreaching?
Transitory reductions in performance during strength training can be caused by three factors: (1) central nervous system fatigue, (2) peripheral (metabolic) fatigue, and (3) muscle damage.
The effects of central nervous system fatigue and peripheral (metabolic) fatigue are very short-lived, and last only a few hours at most.
This means that under normal (non-pathological) circumstances, any reductions in strength that last more than 24 hours *must* be caused by muscle damage.
That’s all it is.
Overreaching (not overtraining) is just where you are routinely training again before you have recovered from the muscle damage caused by your previous workout.
What is the state of overreaching?
When we enter a state of either functional or non-functional overreaching, we are essentially doing workouts before we are fully recovered from the previous one. Our muscles have not yet repaired the damage from the last workout, when ask them to do another one.
Admittedly, this is not the end of the world, since muscles quickly form lateral attachments between the ends of the damaged parts of muscle fibers and the surrounding collagen layers. This quick adaptation allows the remaining, undamaged part of the muscle fiber to contribute to force production, by transmitting its force entirely laterally.
Under most circumstances, requiring the muscle to do a workout again before it has fully repaired the damaged sections of muscle fibers probably does not lead to even more severe damage than would otherwise occur if the muscle had been fully repaired.
Even so, studies examining high-level powerlifters have found that they display abnormally severe muscle damage, even necrotic (dead) muscle fibers. This kind of damage is *extraordinarily* difficult to achieve from a single workout of voluntary, stretch-shortening cycle contractions of the lower body, in trained individuals.
In fact, it is so unusual that it strongly suggests that muscle damage can compound under some circumstances, and become more severe over time, if multiple workouts are done before a muscle is fully repaired.
What differentiates functional and non-functional overreaching?
Functional overreaching is where performance reduces during training, but there is then a subsequent improvement in performance after a taper or cessation of training.
What is going on?
During the overreaching phase, performance is reduced because the muscle is damaged and unable to produce as much force, but other adaptations that contribute to increased strength continue to occur. Then, in the subsequent taper, the muscle damage finally repairs, and the new level of strength produced by the adaptations is revealed.
Non-functional overreaching is where is where performance reduces during training, and there is a return only as far as baseline performance, and then only after a longer period of training cessation.
What is going on?
Just as in functional overreaching, performance is reduced during the overreaching phase because the muscle is damaged and unable to produce as much force. Similarly, it is likely that other adaptations also occur, which contribute to increased strength.
Yet, in this case, once training ceases, the muscle damage is so severe that it takes a long time to repair. In fact, the time taken to repair the muscle is so long that the adaptations that have occurred have also dissipated by the time that the muscle damage is healed.
When is it necessary to use overreaching phases?
Overreaching can be inevitable in a small number of situations, because many of the same training variables that produce muscle damage are also responsible for producing gains in maximum strength and muscle size.
Advanced bodybuilders and high-level strength athletes are particularly prone to overreaching.
As they progress, they often find that they must increase training volume and/or use more eccentric loading, in order to produce greater gains in maximum strength and muscle size.
Yet, these same increases also mean that they need longer to recover.
At a certain point, they may reach a level where they cannot recover in time for the next workout, but if they increase the time between workouts then they will no longer progress, as training frequency will be too low. When they reach this point, it is necessary for them to use an overreaching phase.
Other bodybuilders and strength athletes may choose to employ an overreaching phase, in order to accelerate gains by training more frequently than they might otherwise be able to. There are two risks with this approach, which are (1) they may drift into non-functional overreaching and lose all the gains from the whole training block, and (2) the required taper may actually mean that they only achieve the same gains as they would have done just training at a more normal frequency.
What happens after overreaching phases?
Once the overreaching period has ended, and the taper has started, the accumulated muscle damage can finally be repaired.
But at the same time, all of the adaptations that were achieved during the overreaching phase start to fade away! This includes any hard-won gains in muscle size and maximum strength.
This happens because the mechanisms that produce the adaptations occur in very short time windows, and only arise in response to appropriate workouts.
In the case of muscular changes, muscle protein synthesis rates are elevated for 24–36 hours after a workout, and central nervous system adaptations occur within a few hours at most.
During the overreaching phase, these mechanisms were being triggered regularly by appropriate workouts, and producing adaptations. In contrast, during the taper, the low volume workouts are insufficient to produce any further adaptations, so none can occur. And there are no delayed effects from during the overreaching phase, either.
So how does performance improve after the taper?
The improvements in performance that are observed after the tapering period of “supercompensation” were already created by the adaptations achieved in the overreaching phase. They are just revealed after the taper, once the muscle damage that was concealing them has been repaired.
And let me be really clear about one other thing.
If you didn’t gain muscle mass in your overreaching phase, it cannot magically appear during the taper. There is simply no stimulus that wil trigger the muscle protein synthesis rate increase that you need to gain muscle. Your “supercompensation” phase is not that super. In fact, you will probably see an apparent reduction in muscle size, because of a decrease in muscle swelling. And if you trained to the point where you actually lost muscle, then it is debatable whether it will come back.
What is the takeaway?
Overreaching is just a side-effect of doing too much muscle-damaging exercise, too frequently. For very advanced strength athletes and bodybuilders, functional overreaching may be a necessary evil. For less advanced athletes, it is a (somewhat risky) tool to progress more quickly.
During an overreaching phase, the gains in strength are temporarily masked by the muscle damage. The taper allows the muscle damage to be repaired, which reveals the newfound strength. No new adaptations occur in the taper, and in fact they gradually fade away, until the athlete begins training again.