Common wisdom has it that once a muscle was exercised intensely using resistance training, it should not be exercised again until it has completely recovered. This is considered especially true when a muscle was exercised to failure for several sets, or when eccentric movements were used for added intensity. What I am about to suggest in this article goes against this commonly held dogma. I suggest that advanced trainers only use, on an occasional, infrequent basis, a technique whereby they will exercise relatively small muscles, such as the biceps or triceps, twice a day, both times in an intense manner. I call this technique a "twist" double-split. It takes advantage of the fact that muscles partially recover after a few hours even when worked very heavily, as is the case with advanced training. This technique has worked very effectively for me, where I have reached plateaus in the training of these muscles. In this article I will attempt to explain its raison d’etre and explore its mechanisms of action.

Introduction

Let us first consider the three major subjective symptoms of muscle damage related to exercise. The first is soreness occurring during an exercise and a few minutes to a few hours later. The second is a decrease in the ability of the muscle to perform work, or more simply a decrease in the power it can exert. The micro-trauma endured by the muscle fibers makes them temporarily weaker, and this would explain the decrease in muscle strength. The third is Delayed Onset Muscle Soreness or DOMS, which is a soreness which appears a day or two after the exercise.

Evaluating again the first and second symptoms, what if several hours after a workout, you feel only slight to moderate soreness, and more importantly, what if you can handle nearly the same weight for several more sets? This would seem to indicate that either the muscle had not endured enough damage to significantly affect its strength, or that it has recovered to a considerable degree, or both! Since I often experienced this lack of muscle fatigue symptoms after working relatively small muscles like the biceps and the triceps, I decided to use a double-split with a twist: traditionally one does not work the same muscle during the two sessions comprising the daily double-split; I decided I will work only the same muscle during both sessions.

Caveats, Warnings and Contraindications

The most important issue here is that you should work only a single muscle during both sessions. This pretty much precludes a regular split routine the day you intend to employ this technique. The reason is that this is an extremely taxing routine and to achieve maximal effect you would not want to hinder the ability of the target muscle to perform heavy exercise again during the second session. Performing a regular first session, say in the morning, where you will exercise several muscle groups, can dramatically decrease your ability to intensely exercise one of the muscles you have worked in that session. Overtraining could result also.

The second issue, and this is of paramount importance, is that you should not work your muscle in the second session if you feel considerable soreness or you cannot use a weight almost as heavy as the one you have used in the first session. Remember, these are signs of muscle damage that has not been repaired yet, and true to conventional wisdom, the muscle is not ready for another workout yet.

Another issue is that, as noted above, this technique should only be used by advanced trainers. Beginners and intermediate trainers could suffer acute, local overtraining symptoms such as acute muscle soreness in both its short-term and DOMS forms, or worse yet, muscle cramps. So make sure you have exhausted (pun intended) your options of effectively exhausting the muscle during a single session, using working to failure, forced reps, and eccentric motions (negatives) before attempting the "twist" double-split.

I have not used this method for larger muscles such as quads, lats or pecs; I can not emphatically determine that it cannot (or should not) be used for them. But I do advise you are extremely cautious with experimentation of this kind.

Mechanism of Action

There are several factors that initially limit, and gradually inhibit, the muscle’s ability to perform repeated work such as during the performance of several successive heavy sets. The best known one is the buildup of lactic acid in the muscle during exercise. This is known to be the trigger of the immediate soreness felt after muscle work and a contributor to the soreness felt during the several next hours (but not a factor in DOMS). Let us assume that the buildup of lactic acid plays a role in the protection of the muscle against overwork, by means of both its induction of soreness and reduction of the muscle’s ability to work, or its strength. We can further assume that, as with other protection mechanisms in the body, there is a "safety margin" in the mechanism’s action wherein it takes over before maximal fiber damage has occurred. Although inducing maximal fiber damage is definitely not recommended as a regular, ongoing method for achieving maximal growth, it can be effective when applied from time to time, especially to get out of a plateau or a "rut".