Now that we've established which exercises are most productive, and how to sequence them, we'll take a look at how many sets of each we should do and for how many reps. If you haven't already done so, I encourage you to read the Muscle Growth and The Neuromuscular System series of articles on the 'Training Related Articles' and the 'Physiology Related Articles' pages respectively, before continuing on.
This series is about weight training for muscle size and strength; that, in turn, means that each individual set and rep performed should be done with the mission of increasing muscle size and strength. Having this guideline to work within, we can make some generalizations. We have already established, in one of the above mentioned series, that the main mechanism of muscle growth/strengthening is muscle hypertrophy. And borrowing a section from the Variety: How Often Should You Change Your Routine? article:
Of the two main types of muscle fibers comprising human skeletal muscle (types I & II) the type II fibers generate the most force and have the highest potential for growth. They also require sufficiently "heavy" weights (typically ~75% of 1-rep maximum and greater) in order to activate them. And because these fibers are designed for powerful contractions, they are optimized to use the phosphagen and anaerobic glycolysis systems of energy production. Type I fibers, on the other hand, have a lower potential for growth and predominantly use the oxidative phosphorylation system of energy production.
Clearly, if it's strength and size that we're after, then we should target the type II fibers. This requires lifting at least "moderately" heavy weights. The type II fibers, as you already know, are further broken into subcategories, the most prominant of which are the type IIAs and the type IIBs. Generally, the type IIBs require heavier weights for recruitment than the type IIAs - remember that in order for the next higher threshold fibers to be recruited all of the lower threshold fibers must already have been. In addition, the type IIA and type IIB fibers are also recruited when the need arises for 'fast' movements - the higher the speed of movement required, the more likely that not only the type IIAs will be recruited but also the type IIBs. So, overall, a general rep, weight and speed of lifting scheme can be identified indicating the optimal rep numbers, weights and rep cadences to effectively recruit and train each of these fiber types. A commonly recommended scheme is as follows:
|fiber type||rep range||% of 1-rep max required||rep cadence (neg-pause-pos)|
Keep in mind that these numbers are only guidelines. There is no magic delineation between 3 and 4 reps that means one rep count will train the type IIB's and the the other the IIA's. Likewise, it is not reasonable to assume that the negative, positive and concentric phases of the Squat would be of the same duration as the Bench Press - the squatting motion takes place over a much greater range of motion than the Bench Press. But the general concepts hold.
...the above scheme clearly illustrates that changing rep schemes may, in fact, recruit different muscle fibers in different patterns. For both bodybuilders and strength and power athletes this has significance. Clearly, strength and power athletes will benefit most from training with heavier weights and lower reps in order to maximally stimulate the IIB fibers. Bodybuilders will perform the majority of their training in the 6-12 rep range as this rep count (and corresponding 75-85% of 1-rep max loads) stimulates the greatest amount of protein synthesis in the muscles. (This was covered in the Muscle Growth Part II: Why, And How, Does A Muscle Grow And Get Stronger? article.)
Let's take a closer look at what happens when training in different rep ranges...
It has been established that, for most small muscles, all available muscle fibers will be recruited at loads above 50% of 1-rep max (1RM); for larger muscle groups it may take loads of 80% of 1RM, or more, before all available fibers are recruited. How does this sit with the above suggested rep/fiber schemes? Well, with submaximal loads (i.e. less than 1RM), the highest threshold fibers (the IIBs) may be recruited but the nervous system will not twitch them at their maximum frequency and they, therefore, will not develop their maximum tensions. Essentially, they are recruited but they are not optimally stimulated for strength and power increases.
So, working the IIBs with non-explosive reps in the 3-5 rep range will not force them to twitch at maximum frequency and synchronization, so it will not produce maximum peak strength gains due to nervous system optimization. It may cause the IIBs to hypertrophy, because of sufficient loading and time under tension, which would result in increased strength - especially if a phase of heavier training followed (thereby optimizing the nervous system and allowing the newly hypertrophied fibers to demonstrate their full force potential). It is commonly thought that even training in the 3-5 rep range, however, may eventually cause the endurance aspects of the IIBs to become more prominent until the IIBs lose some of their abilities to generate their previous maximum tensions and, therefore, become more "IIA-like". Recent research has indicated that while this is clearly the case in other mammals, it doesn't seem to occur in humans. For us it appears that the IIBs gain endurance, but they do not lose their abilities to produce maximum force. It may also be that the studies with human subjects simply were not long enough to see this happening.
Higher-rep training for the IIAs would result in them hypertrophying and becoming stronger, but the strength gain would be more prominent in the higher rep ranges because the nervous system would not be optimized for low-rep training. During these sets, as the IIAs fatigue, the IIBs would gradually be recruited, but they would not twitch at maximum frequency and, therefore, develop endurance adaptations more rapidly. This tells us that this type of training is ideal for a Bodybuilder because, in addition to making the IIAs grow (see the Muscle Growth Part II: Why, And How, Does A Muscle Grow And Get Stronger? article), it also allows the IIBs to quickly take on charateristics that will allow for their maximum hypertrophy also.
So, if muscle size is your main concern, you should perform the majority of your training with sets of 6 reps and above. If increased strength is your main goal then you would do well to include sets of 3 - 5 reps, because this type of low-rep training can stimulate hypertrophy in the IIB fibers. Very low-rep training, in the 1 - 2 rep range, results in improvements in neuromuscular efficiency - further making you stronger.
Getting more specific, here's a table that you may find useful:
|training goal||rep range||%age of 1RM required||rep cadence (neg-pause-pos)|
Of course, these numbers are not carved in stone as there will be significant overlap in the training effects of a given rep/set scheme - but they are useful guidelines. Notable exceptions would be for leg work; some people may be able to perform up to 20 reps with 80% of their 1RM. This would still qualify as an ideal training range for type IIA sarcomere hypertrophy and type IIB sarcoplasmic hypertrophy - it is the training load (i.e., 80% of 1RM) which is most indicative of the training effect.
NOTE: For the sake of brevity, all sets referred to in the following section will mean actual work sets - this does not include warm-up sets.
Let's start this section with a little physiology: Each set you do actually increases muscle protein degradation (what do you think happens to all the contractile proteins that you damage?). Yet the body only has the capacity to synthesize protein at a certain maximum rate because there are only so many necessary nuclei, ribosomes, enzymes, substrates, etc available. In addition, enzymes and substrates crucial to the muscle building process are depleted by each set. So the goal is two-fold and clear: Stimulate as much growth as possible, with as little substrate and enzyme depletion as possible, and to do just so much work as to maximally stimulate protein synthesis but not to result in any more protein degradation than is necessary. Because of this critical balance, there comes a point where doing an additional set or rep can do more harm than good.
In addition, the systemic release of anabolic hormones throughout the body must be considered. Performing two sets per exercise has been shown to result in a greater systemic anabolic hormone release (primarily testosterone and growth hormone) than performing only one set. Likewise, performing three sets has been shown to produce a greater response than performing two sets. Above three sets, however, and a situation of diminishing returns seems to develop, at least with regards to hypertrophy-directed training. If low-rep sets are utilized to increase maximum limit strength (as with powerlifting and weightlifting), then more than 3 sets may be performed as low-rep sets involve short times under tension, produce relatively little muscle micro-trauma, and greater set numbers produce greater neuromuscular refinements for strength.
With these considerations in mind, the goal is to find the minimum number of sets you can perform while still stimulating maximum muscular and neural adaptations. From the perspective of systemic anabolic hormone release, three sets per exercise appears to be the ideal ...at least based on the current body of scientific research. Any more than that number will only serve to further strain your recovery 'systems' and tip the scales in favour of protein degradation over synthesis. HIT (High Intensity Training) advocates would recommend performing only one set per exercise to momentary muscular failure. The problem with this approach is that it does not result in an optimum release of systemic anabolic hormones, and the failure effort may over-stress the nervous system, requiring it to need a longer recovery period than the muscular system (see the article Training To Failure: A Look Inside). In addtition, if performing low rep sets (1-3 reps), this may not be enough volume to stimulate optimum muscular adaptation or even significant improvements in neural efficiency. Another equally significant problem with this approach is that low-volume high-intensity training (particularly of the low-rep variety) may be a strong stimulus for irrational hypertrophy - not a desirable adaptation at all (see the article Muscle Growth Part II: Why, And How, Does A Muscle Grow And Get Stronger?).
If muscle size, and not strength, is the main concern then one set of higher reps (6 - 12) may indeed be enough to optimally stimulate sarcomere hypertrophy in a target muscle, but this set may or may not need be taken to momentary concentric failure - though it certainly must be sufficiently 'difficult'. One set per bodypart (in this rep range) may or may not be sufficient to stimulate proportional increases in mitochondria number (sarcoplasmic hypertrophy), so it should not be considered a viable long-term training strategy. A wiser long-term plan would involve multiple (though limited) sets per exercise.
Because of systemic anabolic hormone release and neural adaptations, the compound exercises should be performed for multiple "heavy" sets, with three sets per exercise appearing to be ideal for the purpose of hypertrophy stimulation. A partial list of exercises included in this group would be:
Exercises which recruit smaller total muscle masses are exempt from this '3-set rule' as they do not stimulate a significant systemic release of anabolic hormones anyway.
Overall, the number of sets you perform per exercise will also depend on the total number of exercises that you include in your routine. If you include no isolation exercises you will be able to perform more sets per exercise than if you include some. The more exercises you include in your routine the higher the systemic demands placed on your body. Every aspect of your routine impacts ever other aspect. Remember, all progress must be measured as strength increases - you must regularly see an increase in either the weight you can use for a given number of reps or the number of reps you can perform with a given weight.
I'm going to lay down some general guidelines, but keep in mind that these are just that - guidelines. There are many productive approaches to strength and size training, most of which can be useful for, at least, limited training cycles. What I will present, however, is what scientific research and the practical experience of the past 60 years of drug-free trainees has indicated should form the majority of your training career.
Generally, if you wish to train purely for absolute strength I would say that you should perform between 3 and 7 sets of the compound exercises in the 1 to 5 rep range. If you're after muscle size I would advise you to perform 3 sets of the compound exercises in the 6-12 rep range (up to 20 reps for leg work). If you are after a combination of strength and size I would recommend that you perform a mixture of reps over 3 sets - maybe a set of 5 reps, a set of 8 and a set of 12 reps.
I would especially caution you not to train to failure when performing low-rep sets - you would be seriously risking nervous system 'burnout'.
|training goal||# of sets||reps per set||%age of 1RM required|
If you are including isolation exercises in your routine then you have the option of performing 1, 2 or 3 sets of these exercises - subject to available workout time and your ability to recover from your training in a timely manner. (The subject of ideal recovery times will be covered the next article in this series Making A Strength/Size Routine Part III: Training Frequency). Generally, I suggest performing 2 'hard' sets per isolation exercise.
Bluntly put, if you inadequately warm-up (or not at all) you are asking for an injury. Warming up allows your body to acclimate to the load - many enzymes involved in muscular contraction are more active at warmer temperatures, a 'cold' muscle is more susceptible to tearing. So at no time should you compromise the warming up process. To start our look into warm-up sets let's take a few sections from the series The Neuromuscular System on the 'Physiology Related Articles' page:
This clearly tells us that high rep warm-up sets, except with VERY light weights, will impede the muscle's ability to contract on subsequent sets. It makes sense, therefore, to be safe and limit warm-up sets to sets of 6 reps and under. Each warm-up set should be progressively heavier until you are within range of work set(s). If you were going for a maximum single attempt your warm-ups would eventually themselves become single rep sets. If you were going for a triple you would probably perform your last few warm-up sets with 3 reps (or less). As an example of a warm-up progression, say you planned on Bench Pressing 225 for a set of 5. You warm-ups sets may look like this:
You may be thinking that the warm-up sets get pretty close in weight to the 'working' set weight. This is because working with heavier weights 'primes' the nervous to fire the higher threshold fibers more efficiently. This will actually allow you to lift more weight on the 'work' sets - but don't go so far as to tire yourself out before you get to those 'work' sets. That being said, the effect is much more pronounced when working in the lower rep ranges. If you are doing 'work' sets of 8 or more reps there's no need to warm up to within more than 70 - 75% of your 'working' weight.
There has been a lot of press given to 'cheating' in the bodybuilding world especially. The argument is that by 'loosening-up' your form towards the end of a set (or even right from the beginning) you will be able to get a few extra reps out. More reps with a given weight means more muscle, right? Well, that is generally true, but the fact remains that cheating allows for the performance of more reps (or using more weight) because other muscles are being brought into the motion for 'assistance'. The actual muscles being targeted are working no harder than if a lighter weight was used in stricter form. As far as cheating in order to perform an extra few reps at end of a set is concerned, this presents a clear danger of injury. The danger comes from the fact that the other muscle groups assisting during 'cheating' reps haven't been warmed-up properly for lifting. They are then recruited 'cold' and usually with quick, jerky and imprecise movements - this is a recipe for injury!
There is also a tendency to begin cheating when you are getting along in a training cycle and the weights are getting heavier. You have the tendency to cheat in order to get the reps that you have planned to do with a certain weight. The next time you are tempted to do this remember: If you have to cheat to get the reps then you are obviously not getting any stronger - you probably could have 'cheated' the same amount of weight up last workout. In fact, the only thing you are demonstrating is that you couldn't get this workout's weight with the same technique that you used to get last week's. Don't fool yourself!
In short, 'cheating' your reps is dangerous and usually equates to cheating yourself. Reps should be done with strict, proper form. If you wish to increase training intensity, there are safer and more effective ways to do so.