Fatigue Management is often misunderstood and ill applied in self trained athletes. Muscular failure is reached often and lighter work is disregarded. While training hard is an absolute requisite to get better, knowing when to back off at the appropriate time will definitely help you reach your goals in a faster and safer manner.
One of the most important principle of physical training is overload, which states that to get better, you need to present your body with stimuli of increasing magnitude throughout the training process, stimuli strong enough to disrupt homeostasis, the normal biological state of the body. Overload may be presented mainly through increased volume (sets x reps); intensity (weight); or a combination of both.
With appropriate overload comes adaptation: the body will react to the stress imposed on it by the training process by remodeling itself to become better suited to withstand this stress. Adaptation will take place during recovery times and not during training itself.
If overload is insufficient, adaptative processes won’t be triggered. If it is excessive however, adaptation will not happen either, since recovery capabilities will be exceeded.
So how is it possible to do more sets and more weight but never exceed your capacity to recover?
The answer is not straightforward. To disrupt homeostasis, you need to impose on your body more stress than it can withstand with its current resources. While full recovery after a training session might be possible for beginner lifters because the stimulus doesn’t need to be enormous and their capacity to produce force and work hard is limited, the situation for more advanced athletes is different, since the stimulus presented will need to be so big that it will likely be impossible for them to recover fully and keep a weekly training schedule with several overloading sessions.
Since the recovery capacities will be exceeded, easier sessions might be implemented between overloading sessions but, especially, easier weeks between regular training blocks. While one easier session will usually prevent stress to rise even higher and allow a decent performance at the next hard session, it won’t normally allow for sufficient recovery, if the magnitude of the overload was big enough. Easier weeks, on the other hand, will permit homeostasis to take place once more, normally at a newly reached desired level of adaptation. These weeks are usually termed “deload” weeks and are placed at the end of a training block, after the hardest training week.
While the exact intensity and volume for deload weeks during conventional strength training haven’t been properly reviewed in laboratory studies, anecdotic evidence calls for a reduction in volume from 30% to 50% of regular overloading training and an average intensity between 50% and 70% of 1RM. If your training block was particularly volume oriented, it might be prudent to reduce volume up to 50%, but intensity won’t need to go down as much. On the opposite, if the training block focused more on heavy weights, intensity might need to go down towards the 50% mark while volume might not need to be reduced so drastically. Common loading scheme in a training block usually ranges between three to five normal training weeks and one deload week. Note that while these recommendations can be applied to hypertrophy and strength blocks, they will be somewhat different for a taper leading to a competition, which usually takes place during the last half of a peaking block. There, several consecutive deload weeks might be necessary, with even lower recommendations for volume and intensity than regular deloads, as recovery needs to be complete for competition.
It is important to specify that exercises shouldn’t be drastically changed during deload periods. The introduction of new training means is actually a powerful tool to disrupt homeostasis, best reserved for the beginning of a new training cycle, when the goal is to induce overload once again.
A final point can be raised on training to failure and frequently above 90% of 1RM. While overload is absolutely necessary, it needs to be applied intelligently. Very high intensity training usually brings an excessive amount of fatigue for the level of adaptation it provides as well as an increased risk of injuries. Recovery will be hindered and chances of performing adequately and getting the required training effect from upcoming training sessions reduces drastically, as volume will likely be insufficient while maintaining intensity will quickly become impossible. Attaining muscular failure, especially at these intensities, has been shown to be particularly detrimental to recovery.
While heavy training needs to be done at the appropriate time when the goal is to develop maximal strength for powerlifting (i.e on the last couple of weeks before a competition), keeping intensity between 60% and 85% of 1RM for off-season training blocks allows the integration of adequate volume, which is of primordial importance to promote adaptation. You should see these as building blocks, whereas a peaking block is a realization one that will capitalize on the acquired fitness and allow you to get used to the heavier weights all the while drastically reducing volume to prevent fatigue. Note that, even then, lighter sessions should be about as frequent as the heavy ones to further eliminate chances of accumulating fatigue.
As you can see, overload will not necessarily be presented from session to session; rather, it should be seen as a general trend from one training cycle to another. If heavier weights, more volume or both were performed during a block as opposed to past ones, overload has been achieved, as well as tangible progress. Proper fatigue management goes a long way into making sure that is the course training takes.
 See “Periodization for Powerlifting” article, previously published on this website.
 “[…] a progressive non-linear reduction of the training load during a variable period of time, in an attempt to reduce the physiological and psychological stress of daily training and optimize sports performance.” Mujika & Padilla. Detraining: loss of training-induced physiological and performance adaptations, Part I. 2000, Sports Med, p.80