Training frequency is comprised of two components. They are:
1. How often to train a muscle/muscle group.
2. How often to train overall.
How Often To Train A Muscle/Muscle Group
How often you can train a muscle/muscle group depends largely on how much training volume and intensity you work it with when you do train it. As was mentioned in the article entitled Training To Failure: A Look Inside, some trainers believe that for maximum training stimulus all work sets must be taken to the point of momentary concentric failure (a training style that has come to be called high intensity training – HIT). It is usually also often a part of this philosophy of training that only one work set per exercise should be performed. After the workout the trainee should wait for an extended period (to ensure full recovery and supercompensation) before training that bodypart again.
On the other side of the coin there are the people who believe that sets should not be taken to failure, and muscles/muscle groups trained more frequently. The fact that the trainee isn’t training to failure places less stress on the body’s ‘recovery systems’, allowing the trainee to train the muscles more often.
HITers believe that the surest way to guarantee that the muscle has been stimulated to strengthen/grow is to train to failure; if sets aren’t taken to failure then one can’t really be certain that a training response will be stimulated. More traditional trainers believe that training to failure consistently is “too much” for the body to handle and only leads to “burnout”.
I believe the sources of confusion here – although they are seldom identified – are the nervous system and joint capsules.
Nervous System Considerations
The nervous system and muscular systems may indeed require different recovery times after heavy work. In particular, firing the type IIB fibers at maximal frequencies (utilizing weights above ~85% of your 1 rep maximum) presents quite an effort on the part of the nervous system. In fact, this type of work results in a post-exercise period of nervous system inhibition which often requires 7 or more days for complete recovery. Training the type IIB fibers intensely, in the same pattern (i.e. the same exercise), before this nervous system recovery has taken place will not stress those type IIB fibers maximally because the nervous will not have the capability to fire them frequently enough to produce maximum tensions. The additional workout will not provide worthwhile stress to the muscle but will drive the nervous system further into the recovery zone, requiring even more recovery time. For this reason, an extended rest period between training sessions of the exercise in question is required.
From the Muscular Fatigue During Weight Training article:
In order for a muscle fiber to ‘twitch’ the central nervous system (CNS) must send a nerve impulse to the controlling motor unit. The innervating nerve cannot maintain its capacity to transmit this signal, with optimum frequency, speed and power for extended periods of time. Eventually concentrations of substrates such as sodium, potassium, calcium, neurotransmitters, enzymes, etc. decreases to the point where muscle contraction becomes markedly slower and weaker. If high discharge rates are continued the nerve cell will assume a state of inhibition to protect itself from further stimuli.
Following this, a recovery period of up to seven days or more may be necessary before maximum muscle contraction can be achieved again.
On the other hand, significant research data indicates that anabolic processes within a muscle may be fully completed within 48 hours of bodybuilding type work (~80% of 1RM) – protein synthesis has returned to baseline within the muscle – though this does not necessarily imply such things as complete recovery of connective tissues in and around the muscles and joint capsules. The nervous system, once stressed with ~80 (or greater) of 1RM weights, may indeed take longer than the course of these processes to recover if the set(s) was/were taken to failure or close to it.
Joint Capsule and Connective Tissue Considerations
It must also be acknowledged that many free-weight compound exercises place significant strain on the connective tissues and joint capsules, causing them to deform if heavy weights are used or joint positions are less than optimal during training – such as frequently occurs when “cheating” or failure is reached. This deformation results in proprioceptors signalling the central nervous system about the compromised position of the joint. When this occurs the central nervous system will inhibit the prime mover muscles of the motion, resulting in decreased muscle contraction force …and, essentially, ending the productivity of that set. IF the tendons, ligaments, bursae and supporting muscles of the joint are not given sufficient time to recover from the exercise, then working that particular exercise (or sufficiently similar ones) will not be productive until complete recovery has occured because joint deformation will result in nervous system inhibition.
This is the primary reason why heavy free-weight compound exercises such as Deadlifts, Squats and Bench Presses, typically, cannot be trained heavily every 48 hours. The nervous system is inhibited by proprioceptors in the joint capsules. Extended rest periods are normally required after heavy and intense training (85% of 1RM and sets taken to failure or close to it) on these exercises.
Lastly, from the series The Neuromuscular System:
Once glycogen stores in the muscle are depleted (from prolonged anaerobic glycolysis) they may take several days to be restored.
The Training Goal
The goal is to stimulate the muscle to supercompensate (strengthen/grow) but not to over-stress the nervous system, joint capsules and connective tissues, and intramuscular glycogen and enzyme replenishment processes so that they require extended recovery periods. Increased muscle protein synthesis typically returns to baseline levels with 48 to 72 hours of traditional bodybuilding-style training. There is no sense in having to wait an extra 3 or 4 days after muscle hypertrophy has ceased in order to allow time for the nervous system, joint capsules, connective tissues and glycogen/enzyme replenishment processes to catch up – muscle atrophy (at least to some extent) will likely occur during that period. This is equivalent to taking two steps forward and one step back (or maybe even two steps back). The key is to keep the nervous system and joint capsule recovery and glycogen/enzyme replenishment periods as close to the increased muscle protein synthesis period as possible.
One definite thing that we can learn from the 48 to 72 hour anabolic period is that it is not wise to train a bodypart more frequently than this (once every second or third day). In practice, hard training, drug-free weight trainers will often find that the nervous system and joints require longer periods than this between sessions involving the same exercises – even when sets are not taken to the point of failure (but, of course, they must be intense enough to stimulate supercompensation – ‘difficult’ sets) and sets are kept to a minimum (to minimize glycogen and enzyme depletion).
From Making A Strength/Size Routine Part III: Sets And Reps And How To Perform Them we have the guideline of doing no more than 3 ‘work’ sets per exercise if hypertrophy is the goal and from Making A Strength/Size Routine Part I: Exercise Selection we have the guideline of placing the vast majority of our efforts into the free-weight compound exercises. By limiting specialized isolation work we have automatically cut down on some of the load that the body’s nervous and glycogen/enzyme replenishment systems have to bear. This limited workload represents a reduced systemic strain as compared to routines filled with isolation movements, allowing us to train the compound exercises more intensely and more often. So, since I can work within the bounds of few isolation movements, a concentration on free-weight compound exercises, and 2-3 ‘hard’ sets per exercise, I can then make some generalizations.
If you train your exercises to failure you will require more recovery time (longer breaks between hitting the bodyparts) than if you don’t train to failure. How do you know what is the right balance? Some good guidelines to follow are these:
If you require more than 7 or 8 days rest between intense bodypart training sessions in order to make regular strength gains then you are training too intensely or doing too many exercises or sets per exercise. What is likely happening is that your workouts are placing too great of a demand on your nervous system and joints for recovery to take place in a ‘timely’ manner. The muscles themselves are probably recovering within a few days of training and then more rest days are needed for the nervous system, joints and connective tissues to catch up. More time between bodypart workouts than this and you are risking detraining (atrophy) due to too infrequent a work load.
If you are training a bodypart more frequently than once every two days, and are not experiencing strength gains, then you are either 1) overtraining or 2) not training intensely enough. You are either training too often (and/or too intensely) for your nervous system, joints and connective tissues (and possibly even muscular system) to recover and supercompensate from in the period between bodypart sessions (you could also be doing overlapping exercises on other days and therefore actually ‘hitting’ muscle groups more frequently than you are counting) or you are not training hard enough to elicit muscular adaptation to the load (and also not training hard enough to require significant nervous system/joint/connective tissue recovery time).
In practice, small-boned (and therefore, small-jointed) people cannot tolerate frequent training to failure with heavy loads on the free-weight compound movements. Their small joints and nervous systems require extended rest periods between training sessions, during which muscle atrophy may occur to some degree. However, for these trainees the superior growth inducing capacities of the free-weight compound movements are a definite must. For these reasons, it is recommended that small-jointed trainees interested in muscle growth should utilize predominantly free-weight compound movements in their training routines, but avoid training to failure with heavy loads (high percentages of 1RM) and “cheating” form. In this way, these trainees are able to effectively stimulate growth, while avoiding overtraining on these exercises. In addition, by not imposing excessive nervous system and joint loads, these trainees can train bodyparts more frequently by imposing a heavy/light/medium scheme over the training days and/or selecting different exercises at each session. Total training volume and loads must be limited. This will be covered in a future article in this series and on The WeighTrainer website.
Large-boned trainees typically react positively to heavy training (often to failure) on free-weight compound exercises, even though extended rest periods may be required between sessions. These trainees are ideal candidates for infrequent powerlifting-style routines and other routines which utilize heavy training primarily for strength-building purposes. They may also prosper from more frequent training utilizing the heavy/light/medium scheme and/or different exercises at each training session – as do small-boned trainees. The difference being that large-boned trainees can routinely train more intensely, with higher percentages of their 1RMs, and with higher training volumes than small-boned trainees.
For categorizing purposes, large-boned trainees are trainees whose wrist circumferences (in inches or cm) are greater than 10.5% of their heights (in inches or cm). Their ankle circumferences will be larger than 13.0% of their heights. Small-boned trainees will have wrist and ankle circumferences less than 10.5% and 13.0% of their heights, respectively. It is somewhat common for trainees to be small-boned in their upper bodies, but big-boned in their lower bodies, or vice-versa. These trainees will usually find that their upper and lower bodies react to training at significantly different rates.
How Often To Train In Total
All weight training sessions take their toll on the body’s recovery ‘systems’. Just because you trained legs yesterday doesn’t mean that training shoulders today is a harmless thing to do. The body has depleted glycogen, enzyme, ATP, etc. stores that must be replenished. Training shoulders today may interfere with the recovery processes that are going on in the legs (and central nervous system) due to yesterday’s workout. For strength and size, an everyday workout scheme may produce results for genetically gifted individuals and anabolic drug users, but for a genetically typical drug-free weight trainer they are usually a mistake. NOTE: The exceptions to this rule may be more frequent sub-maximal work, as it doesn’t produce significant metabolic stress, nervous system fatigue and/or joint/connective tissue stresses.
For general strength/size training, experience has taught many a drug-free lifter that he should spend more time out of the gym than in. This means that for typical trainees three weight training sessions per week is the maximum. Training days should always be separated by a rest day (for example, train on Monday, Wednesday and Friday if three days-per-week training is chosen). As was covered earlier, a typical drug-free lifter cannot make optimum muscle and strength gains by training the same exercises intensely three times per week. Therefore, if the trainee chooses to perform three full-body workouts per week, different exercises should be performed on each of the week’s training days or a heavy/light/medium scheme of training must be imposed over the training days – this will be covered further in future articles. (NOTE: Beginners are a special case that should be considered separately). Some, more genetically gifted, individuals are able to prosper on four or more days-per-week strength/size split routines. In general, however, such frequent training does not foster optimum strength gains and is typically adopted to allow advanced bodybuilders to include more “detail” work in their routines or achieve quicker fat loss.
The Balancing Act
Here is a general summary of what has been covered in this series so far, and guidelines for effective weight training routine construction:
* Work each major bodypart once every 2-7 days. The exact frequency will be determined by factors such as rep range, intensity and exercise selection. These factors, in turn, are influenced by bone-structure and nervous system recovery ability.
* Do 3 ‘hard’ sets per free-weight compound exercise.
* Do 2-3 ‘hard’ sets per isolation exercise.
* The vast majority of your workout should be devoted to free-weight compound exercises. Do relatively few isolation exercises – unless you are genetically gifted, or on drugs, they will not accelerate your progress, they will hinder it.
* Weight train no more than 3 times per week. Large-boned and genetically gifted individuals may progress well on 4 days-per-week split routines, though such high frequency is not necessary to produce optimal strength and size gains..
* Be cautious about, and respectful of, training to failure. Unless you are large-boned/jointed with excellent nervous system recovery abilities, you will likely find that excessive training to failure imposes extended rest periods between body part training sessions, and does not result in faster muscle growth. For small-boned trainees, training to failure must be avoided or done so only on the last set of an exercise. The majority of your sets should end with maybe another one or two reps left in you.
The above recommendations are only general guidelines …but guidelines that will produce consistent results for the vast majority of drug-free trainees. The progress of thousands of drug-free trainees throughout the years has verified the efficiency of the above approach. However, if you follow the guidelines for awhile and are not gaining strength at each workout (as measured by fractional strength increases), don’t worry, you just have to start fine-tuning things. By systematically eliminating all possible reasons for any lack of progress you will find the routine that actually produces results for YOU, and not just a routine filled with the promises of a drug-using, genetically gifted champion. The above guidelines provide the proper place for you to start. Continue reading the rest of the Making A Strength/Size Routine series and especially the up-coming article, Making A Strength/Size Routine Part VI: Balancing The Balancing Act, for further advice on constructing the best possible routines for you.