I like to be strong, but I don't wear three-ply titanium shirts and compete in bench press competitions. No, I like to be strong because that helps me build muscle. I like to sprint too, but I have no hopes of winning medals in track & field events, and I don't play any sports. Nope, I only sprint because it makes my ass all round 'n perky.
See, I lift weights mostly for egocentric, superficial reasons: I do it to look good and feel good. I do it because those old black and white pics of Arnold inspire me. I do it because being fat and "skinny fat" doesn't turn the heads of women.
I'm sorry. I apologize profusely for loving good ol' aesthetic driven bodybuilding. I am so ashamed.
Okay, not really. I'm not ashamed at all. In fact, I sometimes think we forget about bodybuilding. Many Testosterone Nation writers are mainly focused on performance. That's cool, because performance goals often lead to "looking good naked" goals, but I honestly couldn't care less about how some shot putter or drugged-up powerlifter trains. It ain't my bag, baby.
That's why I think Christian Thibaudeau is one of the best "bodybuilding coaches" out there. He has the background in performance training; he knows a whole lot about speed and power and strength. He can quote lots of fancy European studies. But he's also a bodybuilding historian, he's trained competitive bodybuilders, he's struggled with fat-boy issues, and he's stepped onto the stage himself. This makes Thibaudeau, well, the "perfect storm."
When I have a question about pure aesthetic lifting, I turn to Thibaudeau. Hence the straightforward idea for this interview: questions about bodybuilding. Here's what I learned.
Testosterone Nation: Let's start with some info on genetics. While everyone can build muscle, it seems that some people can do it at ten times the rate of others. They also just keep getting bigger while most average people reach a ceiling on their development. Assuming there are no steroids involved, what genetic issues go into building a big, muscular body?
Christian Thibaudeau: I think that we have four aspects to consider. First, we have the muscle tissue composition itself. It's not a big secret that fast-twitch muscle fibers/high-threshold motor units have a much greater growth potential than their slow-twitch/low threshold counterparts.
So in that regard, an individual with an unusually high level of high-threshold motor units will have an easier time gaining muscle mass. We could also include insertion points/muscle belly length in the muscle composition category. Longer muscle bellies have a greater potential for growth than shorter ones.
Then we have the hormonal factor. People vary widely in their natural capacity to produce various anabolic hormones (Testosterone, growth hormone, IGF-1, etc.) and in their sensitivity to these hormones. Being sensitive to the various anabolic hormones means that your body will react to a greater extent to even a small elevation.
This sensitivity issue explains in part why some individuals blow up when they use small doses of steroids while others gain little muscle mass even with very high doses. I know several gym rats who take much higher doses than a lot of top pros and hardly look like they train at all! I also know some top amateurs and pros who actually use very little anabolic support. Obviously, someone who naturally has a higher level of anabolic hormones or is more sensitive to them will be able to build muscle at a faster rate.
The third aspect is the nervous system, and it might very well be the most important one of all since it's the one in which we have the greatest control. To maximally stimulate growth in a muscle, you must be able to recruit as many high-threshold motor units (HTMUs) as possible. And not only do you have to recruit them, you have to fully fatigue them. A more efficient nervous system means better efficacy at recruiting these HTMUs.
When someone has a lagging muscle group, more often than not it's due to an inefficient neural activation in that muscle group. It's tempting to blame muscle fiber dominance for lack of growth in certain muscle groups ("My XYZ is slow-twitch dominant so it can't grow no matter what"), but except for a very few extreme cases, most individuals will be at least 40-50% fast-twitch in most muscle groups.
While this won't allow them to grow as fast as someone who's 80-90% fast-twitch, it does mean that all of their muscle groups do have the potential to gain size. So except for the few rare cases of actual slow-twitch dominance (80-90% slow-twitch), when a muscle group is lagging it's mostly due to an inability of the neuromuscular system to fully recruit the HTMUs.
The fourth and final aspect is a psychological one: tapping into these HTMUs requires a tremendous level of effort in the gym as well as a high pain tolerance. People who aren't motivated and aren't giving it 100% in the gym will obviously have a harder time stimulating muscle growth. Simply lifting the bar from point A to point B won't stimulate muscle growth; it's what happens in the muscle and in the CNS that'll dictate how much muscle you'll gain.
T-Nation: Doesn't arm and leg length also play a role in "jacked potential?"
Thibaudeau: Obviously, other factors such as limb length will play a role in muscle growth potential too, or more precisely in giving the illusion of size. An individual with shorter limbs won't have to gain as much size on his arms for them to look big. A guy with super long arms will have a harder time making them look impressive.
But the first four factors are the most important ones when it comes to your actual capacity to build muscle tissue. However, your body structure can influence the way you look, independently of the muscle size aspect of it. For example, people with a wide clavicle and narrow hips will look much more muscular than they actually are. Those with a narrower clavicle and wider hips won't look as good as their level of muscularity normally would.
T-Nation: Okay, one of the most common questions aesthetic-minded lifters have is, "Should I bulk or cut?" Any guidelines there?
Thibaudeau: As you know, my article against all-out bulking caused quite a stir here at T-Nation! But I think that a lot of people didn't get the actual message behind it.
My belief is that you can't build a lot of muscle without consuming a caloric excess, or more precisely, consuming more nutrients than you use up each day. I think we can all agree with that. However, you can't force feed your body into building more muscle, especially if you're natural.
Your body is limited by its own physiology/biochemistry when it comes to building muscle mass; it has a certain capacity to take the nutrients ingested and turn them into muscle tissue. If you're not eating as many nutrients as you can utilize for growth each day, you'll benefit from increasing your caloric intake (you'll gain muscle faster). But once you reach the nutrient utilization ceiling of your body (which is determined mostly by the level of anabolic hormones in the body), simply adding more calories or nutrients won't lead to a faster rate of growth.
(Obviously, chemically enhanced bodybuilders face a different reality since the anabolic support they use will allow them to push that utilization ceiling upwards by bypassing their natural biochemistry.)
So what I'm against is a caloric intake that's drastically above your daily needs. If you have a daily energy expenditure of 3000 kcals/day, you probably have a utilization ceiling of around 3750-4000 kcals (could be more or less depending on your hormonal status and metabolic rate). Increasing your caloric intake from 3000 to 4000 kcals will indeed lead to a faster rate of muscle growth, but going from 4000 to 5000 kcals/day will likely not result in any additional muscle tissue, but it will lead to more fat being gained!
So if your main objective is to gain muscle mass, you have to eat more nutrients than you use each day, but you shouldn't eat so much that you end up gaining more fat than muscle. You should stay at a level that allows you to at least look decent "nekid" and only a few weeks of dieting away from being in good shape.
Obviously we must also consider the level of development of an individual. A beginner with basically no muscle mass will probably need to accept a bit more fat gain as he builds up his muscle base than someone who's already in very good shape. However, I still think that we should avoid gaining an unacceptable amount of fat for the sake of adding muscle.
Now, what's unacceptable will vary from one guy to the next. I personally don't like being above 10% body fat and actually stay closer to 8% year round. Other people still look and feel good at 12-14%. It's an individual thing.
But regardless of your caloric intake, or if you're bulking or cutting, you should stick to clean food 90% of the time. I still believe that "bulking" shouldn't be used as an excuse to pig out on junk food.
T-Nation: You know someone is going to post a picture of an unhealthy, heavy steroid user and say, "Oh yeah, this guy eats Big Macs all day and look at him!" In fact, I have a photo of the people who say that:
Moving right along... It seems that a lot of gym rats want to specialize on body parts too soon. And that brings us to the "stick to the big basics" vs. specialization training debate. Any advice there? When should a person start worrying about bringing up certain body parts?
Thibaudeau: Beginners obviously shouldn't specialize. They don't need to, especially since most of the time any perceived weaknesses might simply be due to improper training in the past (e.g. only training the "mirror muscles") or to the previous activity background. For example, someone who spent years practicing alpine skiing will have dominating legs right off the bat, but that doesn't mean he shouldn't train his legs when he begins lifting weights.
At first, everybody should use a balanced training program. That doesn't mean only "sticking to the basics." In fact, sticking to the basics can actually go against the balanced training philosophy! Someone with strong shoulders and triceps might under-stimulate his pectorals if he only uses "the basics" (only performs heavy pressing movements for the chest). Another guy with powerful biceps might not fully stimulate his back if he only uses "the basics" (only performs pulling movements for the back) since the biceps will take over in the movement.
Beginners should learn to properly activate and stimulate every major muscle. This will prevent any future problems with the CNS's capacity to recruit a muscle group. To do this, beginners need to use both basic lifts and isolation/focused movements to make sure that every muscle group is properly stimulated.
T-Nation: Okay, so specialization should only be used by individuals who already have a good foundation of muscle. But what constitutes an acceptable level of muscle mass?
Thibaudeau: Well, that's an individual thing, but I think that someone should gain at least 20 pounds of muscle mass with a balanced approach before even considering specialized training. And even then, specialization shouldn't be abused. It's a strategy specifically designed to bring up a lagging muscle group by hitting it often (to improve the CNS's capacity to recruit it). As such, it's best used by bodybuilding competitors or individuals with an obvious imbalance.
Specialization can also be used by individuals with a postural problem. For example, if someone has a severe shoulder anteriority, specializing on the back, rear delts, and external rotators is probably a good idea, especially with athletes who can increase their risk of injury if they have an incorrect posture.
T-Nation: Interesting stuff. Now, visible abs have always been important for the "artistic" physique, but these days everyone wants that lower abs V-shape. What the heck is that muscle group exactly and how do you get it?
Thibaudeau: This "V" is actually the tendons of the external obliques as well as the lower portion of the rectus abdominis.
So really, the only way to "get" this V-shape is to train your obliques and the lower portion of your abdominals. And of course, you have to get your body fat down to a fairly low level.
The following exercise pairings could do the job, at least from the muscular development standpoint:
Superset 1: High pulley woodchop (8-12 reps per side) and twisting crunch (max reps)
Superset 2: High pulley crunch (8-12 reps) and leg tuck (maximum slow reps)
On these last two exercises, try to activate the pelvis floor (imagine having to pee and holding it in).
T-Nation: Cool. We always hear that to get big arms (or whatever muscle group) we shouldn't use isolation exercises or machines too much. But that's what every pro-bodybuilder does!
The experts basically tell us to train in the opposite manner of how the best in the world train. That seems odd, doesn't it? I mean, we're told that flyes are a sissy, worthless exercise, but you know what? Every guy with an impressive chest I've ever seen does flyes!
Thibaudeau: To develop a certain muscle group you must use the exercises that provide the best growth stimulus for that muscle. Depending on the muscle we're talking about, as well as the muscular dominance of the individual, these exercises can be multi-joint, isolation, or both types of exercises. We really shouldn't divide exercises as multi-joint and isolation anyway, but rather as "effective and ineffective" exercises.
Take the chest for example. For the majority of gym rats, the bench press is probably one of the most overrated exercises around. Why? It's quite simple: the regular bench press is a lousy pectoral exercise for most individuals!
I've rarely seen someone who focuses only on the bench press have good pectoral development. Most of the time these individuals will have big triceps and/or deltoids, but a very incomplete chest development. They normally have a decent "outer portion" but the pec gets thinner as we move toward the sternum. The strongest bench pressers normally have underdeveloped pectorals (compared to their other pressing muscles) unless they also perform better chest exercises in their programs.
The powerlifting bench press is first and foremost a triceps exercise. To make the bench press an effective pectoral movement we must use a wide grip, flare the elbows out, and bring the bar down to the collarbone (known as a neck press).
However, you can't use as much weight as with a regular bench press. And for some people, the ego is quick to jump in and they revert back to a less effective variation of the bench press. This is why I wouldn't include the bench press on my list of the most effective chest movements. But if you're able to leave your ego at the door and perform a proper neck press, then it can be a useful addition to a good pectoral program.
T-Nation: How about biceps? Again, there seems to be an anti-curl trend going on, and while I agree that close-grip weighted chins are awesome arm builders, I've also never seen a guy with impressive biceps that didn't curl.
Thibaudeau: Yes, the same logic can be applied to the biceps. We should select exercises not because they fall either in the multi-joint or isolation category, but rather because they're the most effective exercises to do the job... and that job is to make the biceps grow!
To me there's no question that curling exercises are necessary to develop the biceps to their maximum potential. If someone is using heavy pulling movements to build their biceps, chances are they're not doing these heavy pulling exercises properly and as a result will get an inferior back stimulation. This will lead to the faulty motor habit of over-stimulating the arms and under-recruiting the back during pulling movements.
The best exercises for a muscle group are the ones that place the targeted muscle group in a loaded stretch position prior to the concentric portion. Remember that a stretched muscle is a recruited muscle.
We can also increase biceps activation by increasing its stabilization role while an arm flexion movement is being performed. An example of this is a single arm barbell curl. The long bar increases the need for stabilization, and that action is provided by the biceps which will act as a static supinator.
In my opinion the best arm flexor exercises are (in no particular order):
• Incline dumbbell curl. Fully stretch the biceps at the bottom position. Don't rotate your arms. Start in a supinated (palms up) position and curl that way too.
• Incline hammer curl. Again, fully stretch the biceps at the bottom position. Don't rotate the arms. Start and end in a hammer grip position.
• Behind back low-pulley curl. Again, aim for that maximum stretch.
• Behind back low-pulley hammer curl
• One-arm barbell preacher curl. Very important to keep the bar perfectly parallel to the floor.
• One-arm barbell curl. Again, very important to keep the bar parallel to the floor.
You'll notice that in all of these exercises (except the hammer variations) the wrist is either extended or neutral, to focus more of the stress on the biceps. That's not to say that there aren't any other great biceps exercises, but from experience, these are the best ones out there.
T-Nation: Cheat movements: good or bad if your main goal is building muscle?
Thibaudeau: It depends on what you mean by "cheating." If cheating means using a faulty movement pattern to be able to lift the weight from point A to point B, taking the tension off of the target muscle group, then I'm against it, at least when it comes to stimulating muscle growth.
When you're training to build muscle mass you aren't lifting weights from point A to point B; you're contracting muscles against a resistance. When the target muscle group is fried it's possible to continue on with the set by relying on secondary muscles. However, this won't have much benefit on the target muscle itself. In fact, it may become detrimental as over time it could lead to improper recruitment patterns where you have more and more difficulty recruiting the target muscle group because you over-relied on the secondary muscles.
Some will argue that if you cheat a little bit at the end of a set you can get those extra two or three reps. Yeah, okay, I agree. But these aren't "money reps" in that they won't efficiently hit the targeted muscle group.
When a muscle reaches technical failure (when it can't complete a task at the prescribed parameters) it doesn't make much sense to continue to try to pound it. It's much more efficient to add an extra set if you feel that the HTMUs haven't been fully stimulated.
T-Nation: Okay, so instead of cheating out an extra couple of reps, just add another set. I like that idea.
Next question: Arnold, at times, trained twice per day, adding up to several hours in the gym five or six days per week. Today we all know that spending over an hour in the gym is a waste of time... and none of us are as big as Arnold. Coincidence? Have we taken the "keep it to an hour or less" rule too far or is that still good advice?
Thibaudeau: That could be a two part answer! First, I think that we need to mention that Arnold only trained twice a day during his pre-contest period. So basically only eight to twelve weeks out of 52. The rest of the year he'd train less often, three to five times per week, not using double splits.
We also need to say that this was pretty much how most guys trained during the pre-contest period at the time. In fact, some guys trained much longer than Arnold did. For example, Pete Grimkowski used to train as much as seven hours per day at the peak of his career. Serge Nubret trained for three hours, plus one more hour of abdominal work six days a week. Mike Katz would also train four to five hours per day.
The thing is these guys didn't do much cardio to shed the fat. The super-high volume of work increased caloric expenditure, which helped them lose fat and get into contest shape. Nowadays a lot of bodybuilders will do 45 minutes of cardio in the morning, a weight training session in the afternoon, and a second 30-45 minute cardio session at the end of the day.
So while they aren't doing as much weight training as the old timers did, their level of physical activity is almost as high. You also have modern bodybuilders who do train twice a day during their pre-contest period, Jay Cutler being one example.
To be honest, I don't see anything all that unusual about this volume of physical activity. I come from an athletic training background and I've worked with athletes who trained a total of four to six hours per day, six days a week. Obviously that wasn't all gym time, but it was time spent doing physical work.
Figure skaters and gymnasts train around four to five hours for their sport and this type of training is very physically demanding. Then I have them in the gym for an hour three times a week. This made for a total of around 30 hours of training per week. Go tell a gymnastics coach that he shouldn't have his athletes train for more than two hours, four times per week, and he'll have you committed! For years and years, the better competitive athletes have trained 20-30 hours per week with great results.
When I worked as the head strength & conditioning coach for a top sport/studies program, we had over 400 student-athletes from 26 different sports training with us. All of them trained at least three hours per day, either in the gym, on the track, or on the field. If elite athletes can not only survive but thrive on 20-30 hours of training per week, I don't see why a bodybuilder couldn't train 10-16 hours per week in the gym.
The thing is that most bodybuilders, or guys training only to gain muscle, are out of shape and have a very low work capacity. This is probably directly due to the fear of overtraining. These individuals can't jump into a very high volume of weekly training without crashing and burning because their body isn't accustomed to handling this kind of physical work.
Work capacity and exercise tolerance is something that's gradually built over time. If you jump straight from three hours of weekly training to 12 hours, yeah, you'll burn out! But it is possible to train more and more as your body adapts to physical work. In fact, the more you can train without exceeding your recovery capacities, the more you'll progress.
So to recap:
• Old-timers had a super high volume of gym work because they used the added strength work to lose fat instead of relying on a lot of cardio.
• Old-timers used this approach only during the pre-competition period to shed body fat, not really to gain muscle.
• Modern bodybuilders still perform a high level of physical work in the pre-contest period, but the trend has shifted to an increase in the amount of cardio and a decrease in lifting volume.
• If you train more, without exceeding your capacity to recover, you'll progress more. Elite athletes from all sports are living proof of this.
• You must "train" your body to be able to handle more work by gradually increasing training volume over time (if you decide to go for the higher volume approach). Do not make huge jumps in volume or frequency.
T-Nation: Okay, we're also told by many experts never to train to failure, but again, most top bodybuilders train to failure. Is this a testament to their great genetics and drug use, or are we normal folks missing something here by avoiding failure training?
Thibaudeau: I'll take the easy way out with this one! I'm working on a new book that will be called High-Threshold Muscle Building and there's a section on training to failure. I'm gonna draw from it to give the readers a more complete answer... and to get the word out about the book!
From the upcoming High-Threshold Muscle Building:
Few concepts in the world of strength training have been more hotly debated than the need (or not) to reach muscle failure during your sets. Is it necessary for muscle growth? No, however I feel that it's necessary for optimal growth.
Some argue that training to failure is either dangerous or can lead to CNS fatigue. Others argue that training to failure too often will cause an excessive amount of muscle damage and can lead to localized overtraining. I think that some of these misconceptions stem from the fact that muscle failure isn't well understood.
The biggest proponents of training to failure have defined it as "creating a maximum amount of inroads to the muscle on each set." This is fine and well. However, am I the only one who doesn't understand what they mean by that? So I feel that it's important to correctly describe what muscle failure is and why it happens. This information will allow us to make an objective assessment of the need (or not) of training to failure.
What is the Point of Failure?
Failure is actually not complicated to understand. It's simply the incapacity to maintain the required amount of force output for a specific task (Edwards 1981, Davis 1996). In other words, at some point during your set, completing repetitions will become more and more arduous until you're finally unable to produce the required amount of force to complete a repetition. This is muscle failure. Failure isn't the amount of "inroad" to the muscle; it's nothing esoteric as we just saw.
The Causes of Failure
If the concept of training to failure is actually quite easy to grasp, the causes underlying this occurrence are a bit more complex. There's no exclusive cause of training failure, rather there are quite a few of them.
1. Central/Neuromuscular Factors: The nervous system is the boss! It's the CNS that recruits the motor-units involved in the movement, sets their firing rate, and ensures proper intra and intermuscular coordination.
Central fatigue can contribute to muscle failure, especially the depletion of the neurotransmitters dopamine and acetylcholine. A decrease in acetylcholine levels is associated with a decrease in the efficiency of the neuromuscular transmission. In other words, when acetylcholine levels are low, it's harder for your CNS to recruit motor-units and thus you're unable to produce a high level of force output.
2. Psychological Factors: The perception of exhaustion or exercise discomfort can lead to the premature ending of a set. This is especially true of beginners who aren't accustomed to the pain of training intensely.
Subconsciously (or not), the individual will decrease his force production as the set becomes uncomfortable. This is obviously not an "acceptable" cause of failure in the intermediate or advanced trainees, but beginners who are not used to intense training could slowly break into it by gradually increasing their pain tolerance.
3. Metabolic and Mechanical Factors: It's well known that an increase in blood acidity reduces the magnitude of the neural drive as well as the whole neuromuscular process. Lactic acid and lactate are sometimes thought to be the cause of this acidification of the blood, but this is actually not the case. The real culprit is hydrogen.
Hydrogen ions can increase blood acidity, inhibits the PFK enzyme (reducing the capacity to produce energy from glucose), interferes with the formation of the actin-myosin cross bridges (necessary for muscle contraction to occur), and decrease the sensitivity of the troponin to calcium ions.
Potassium ions can also play a role in muscle fatigue during a set. Sejersted (2000) has demonstrated that intense physical activity markedly increases extra-cellular levels of potassium ions. Potassium accumulation outside the muscle cell leads to a dramatic loss of force which obviously makes muscle action more difficult.
Finally we can include phosphate molecules into the equation. Phosphate is a by-product of the breakdown of ATP to produce energy. An accumulation of phosphate decreases the sensitivity of the sarcoplasmic reticulum to calcium ions. Without going into too much detail, this desensitization reduces the capacity to produce a decent muscle contraction.
4. Energetic Factors: Muscle contraction requires energy. Strength training relies first and foremost on the use of glucose/glycogen for fuel with the phosphagen system (ATP-CP) also playing a role.
Intramuscular glycogen levels (glucose reserve in the muscle) is very limited and can become depleted as the training session progresses. The body can compensate by mobilizing glucose stored elsewhere in the body (but this amount is also finite), by transforming amino acids into glucose (which is a less powerful way of producing energy for intense muscle contractions) or turn to free fatty acids and ketone bodies.
The last two solutions can't provide energy as fast as intramuscular glycogen can. As a result, even though it will be possible to continue exercising with a depleted muscle, it's impossible to maintain the same level of intensity and force production.
So as you can see, it's impossible to attribute muscle failure to a single phenomenon. Rather, it's a mix of several factors that cause muscle failure. Contrary to popular beliefs, reaching muscle failure in one set doesn't ensure the complete fatigue and stimulation of all the muscle fibers in a muscle. Far from it!
Failure can occur way before full contractile fatigue has been reached. This means that the "one set per exercise to failure" method isn't ideal for maximal growth. As a part of a more complex training plan it can be beneficial from time to time, but not as a discrete training system.
At some point it becomes necessary to increase training volume to fully stimulate a larger pool of muscle fibers. Remember that simply recruiting a motor-unit doesn't mean that it's been stimulated. To be stimulated a muscle fiber must be recruited andfatigued (Zatsiorsky 1996).
If training to failure doesn't ensure full motor-unit stimulation within a muscle, not taking a set to positive muscle failure (the point where a technically correct full repetition can't be completed) is even less effective since it won't fatigue the HTMUs as much. And remember that a muscle fiber that isn't fatigued isn't fully stimulated! In other words, training to failure doesn't guarantee maximal motor-unit stimulation, but not taking a set to failure drastically reduces the efficacy of a set.
This indicates that high volume of work without going to failure isn't ideal for maximal muscle growth (but it's okay for strength and power oriented training). But at the other end of the spectrum, low-volume training taken to failure isn't ideal either. Failure and volume are both needed for maximal motor-unit stimulation. That's not to say that you should use a huge volume of work, but a moderate volume of sets taken to failure is necessary for maximal muscle growth.
And what about the so-called CNS drain that can occur when you take your sets to failure? I do agree that for continuous improvements to occur one should avoid CNS burnout/overtraining (also called the Central Fatigue Syndrome). And I understand the theory behind avoiding going to failure: going to failure increases the implication of the nervous system because as fatigue sets in (accumulation of metabolites and energetic depletion) it must work harder to recruit the last HTMUs.
The argument is that we should minimize training that has a high demand on the nervous system. However, most people who espouse the "don't go to failure" theory are generally proponents of heavy lifting and/or explosive lifting, both of which are just as demanding (if not more) on the nervous system as training to failure. Why are they against one neural intensive method but for another one?
The fact is that the CNS is an adaptive system just like the rest of our body and it can become more efficient at stimulating muscle contraction when it's trained properly. And while CFS is a real problem, its occurrence in bodybuilders or individuals training for muscle mass gains is minimal, close to nil in fact.
Sure, we can suffer from CNS fatigue after a training session (just like our muscles are fatigued too), but the body can recover from that. Neurotransmitter depletion might be a concern, but rarely is a real problem. Using a supplement like Biotest's Power Drive can help in that regard by boosting acetylcholine and dopamine levels.
1. Muscle failure isn't an indication that every muscle fiber within a muscle has been fully stimulated. However, going to failure will make sure that you're getting the most out of that set.
2. Muscle failure can occur because of neural, psychological, metabolic, or energetic factors.
3. A moderate amount of work to failure is required for full motor-unit stimulation within a muscle.
T-Nation: Good stuff, Christian, lots to think about. Thanks for the interview!