Physique Development: Fitness Myths & Facts

There are a number of misunderstandings in the fitness world. One that I would like to discuss is the ever popular myth, "Use light weights \ high reps for cuts and heavy weights \ low reps to build muscle mass". Many are still under the impression that this is a fitness fact. Lighter weights with higher reps will emphasize developing muscular endurance while heavier weights with lower reps will emphasize developing muscular strength. This is a fitness fact. The most dominant factor in determining your physique potential is your genetic makeup. Just observe two individuals that strength train together, are of the same age and sex, and have similar lifestyles (e.g.- nutrition). Their results and physiques will vary as a result of their genetics.

There are many predisposing factors that will determine your muscular size, strength, and leanness potential. Testosterone levels, muscle fiber types, muscle and tendon lengths, tendon insertion points, neurological efficiency, somatotype (thin and wiry, muscle bound, or round with high body fat), and limb length will all factor in. For example, someone that is an ectomorph (thin and wiry) but has a high level of neurological efficiency will be stronger than he or she appears to be.

Although he \ she will not be very muscle bound, he \ she will be able to utilize more muscle fibers in a given muscle(s) than someone that is a mesomorph (muscle bound) but has a low level of neurological efficiency. In fact, the former can be equally as strong as the latter because of this predisposition. However, an ectomorph will never develop very large muscles (naturally that is) because this somatotype simply won't permit it.

On the other hand, a male that has above average levels of free serum testosterone will typically be a mesomorph because testosterone is the primary hormone responsible for muscle hypertrophy. This individual would increase in muscle size and strength rather quickly and significantly from almost any strength training protocol. Even if he follows a "cut" routine of lighter weights and higher reps, his "light" weights would soon become heavier because of the fast gains he would experience. It is important to remember that muscle definition won't show from any strength training routine if one's body fat is too high.

With regard to women and strength training, women should strength train the same way that men do. While some claim that women should use light weights and high reps to tone, shape, and sculpt, this is quite misleading. While there are a few women that have the potential to develop large muscles, most don't. This is because women typically have lower levels of serum testosterone, more body fat, and shorter muscle bellies. A woman's muscle is exactly the same and responds to weight training exactly the same way as a man's does.

If someone is looking to gain muscle size and they are not meeting their required caloric intake each day, it won't matter how heavy their weights are and how low their reps are. Muscle growth won't be significant because the extra calories needed for supercompensation (recovery and growth) aren't being met. Someone that strength trains and is looking for more muscle definition or "cuts" may need to slightly reduce or change calories consumed and or increase aerobic exercise to accomplish this.

While there are varying programs and controversies regarding the ways to strength train (e.g.- number of sets performed and muscles worked in a given session), there are some standards that should be followed.

All reps should use a full range of motion or pain free range of motion.

The movement speed should be slow and controlled. How slow? Nobody knows the ideal rep speed but when in doubt, move a little slower. Lifting in about 2 seconds and lowering or returning in about 4 seconds is a good guide to follow.

Rep range varies considerably but it is generally accepted that 8-12 reps per set is an excellent guide to use to increase muscle tone, size, and strength.

Pause at the midpoint of each rep but don't lock out the working joints.

Maintain proper body alignment. Don't alter body position to gain a leverage advantage.

Focus on the muscles that are being worked and breathe continuously.

Unless you are looking to maintain your current muscle strength, tone, and size, follow the progressive overload principle. Each set or session should have a goal of improving from the last. Increasing the resistance and or repetitions are the most common ways to accomplish this. Slowly movement speed and altering rest time between sets are others. Some increase training volume (e.g.-more sets) to continue to progress. Others, including yours truly, focus on increasing the intensity.

The greatest training factor that determines our response to exercise is our intensity or degree of effort. While increased exercise volume can enhance results, it brings with it the increased potential to overtrain. The greater the intensity, the greater the training response. Every work set that is performed should at least become challenging at the end reps (muscle fatigue). More advanced trainees may take each work set to momentary muscle failure. That is, the set ends when you cannot complete another rep with proper form. This is the heart of the High Intensity Training (HIT) school.

HIT routines typically consist of full body or upper \ lower body routines. These protocols consist of each work set going to muscle failure and, at times, adding in advanced techniques such as forced reps, breakdowns, or super sets to name a few. This is not for the beginner but once tolerated, produces significant muscle responses.

Getting back to physique specific routines, we all have a mixture of slow and fast twitch muscle fibers. There are subclasses of the fast twitch category but basically the slow twitch fibers are slow to fatigue and produce low levels of force. The fast twitch fibers fatigue quickly but produce high levels of force. The average person has about two thirds slow twitch and about one third fast twitch.

Strength training is an anaerobic exercise. Anaerobic metabolism lasts about 40-70 seconds in someone who has this average mix of slow and fast twitch muscle fibers. So, a set of 8-12 reps, using a 2 / 4 cadence, will have our anaerobic metabolisms exhausted by the end of the set if the resistance is great enough. Extensive research has shown that approximately 75% of the one rep maximum (1 RM) is the appropriate intensity to overload our muscles. Beginners may use a slightly lower resistance (65% 1 RM) but once an establishing a baseline of strength, 75% is ideal.

Some individuals have a greater than average percentage of slow or fast twitch muscle fibers. Those with more slow twitch fibers will be able to achieve about 14-16 reps with 75% of their 1 RM because their anaerobic systems will take longer to fatigue due to their high percentage of "fatigue-resistant" muscle fibers. An individual with an above average amount of fast twitch muscle fibers will probably achieve only 5-7 reps with 75% of their 1 RM because their anaerobic systems will fatigue faster than average because they have more muscle fibers that fatigue quickly. However, while both of these types of individuals may be using 75% of their 1 RM, 75% of a 1 RM from the individual that has more fast twitch fibers would be significantly heavier as a result of having more "strength" fibers.

The muscle fiber ratio varies to a degree from one muscle to the next and some muscles typically consist of more of one of the fiber types. For example, the soleus (lower leg) typically contains more slow twitch muscle fibers while the triceps muscle typically contains more fast twitch muscle fibers. The only absolute way to determine you muscle fiber makeup is to have a muscle biopsy done. However, a crude test can be performed only if a 1 RM can be safely determined. After determining your 1 RM on a leg extension, rest for 5 minutes and then attempt as many reps as possible with 75% of your 1 RM using a 2 / 4 cadence.

The number of reps achieved will give you a ballpark figure of what your makeup is. Less than 8 reps achieved points to more fast twitch, 8-12 reps achieved points to the average mix, and more than 12 reps completed points to more slow twitch. Perform the same procedure on an upper body exercise such as a machine pullover. An even cruder method is to note what you or someone else typically does for exercise. If someone predominantly performs aerobic exercise, they may be more slow twitch. If they predominantly perform weight training, they may be a little more fast twitch. If there is a balance in exercise forms, there is likely the typical makeup.

Unfortunately, individuals that are a greater than average percentage of one or the other contribute to the physique specific training myth. An individual that has an above average amount of slow twitch muscle fibers will likely use "light" weights and high reps since they are usually not very strong and it would take longer than average for them to fatigue when weight training. These individuals are typically lean because slow twitch fibers don't hypertrophy significantly and these persons usually participate in endurance activities because they do well in them as a result of having more "fatigue-resistant fibers". The increased cardiovascular work leads to less body fat. However, many will see their high rep \ light weight routines as the reason for their physique.

On the other hand, the individuals that have an above average amount of fast twitch muscle fibers will probably use "heavy" weights and low reps since they fatigue quickly when weight training. These persons are likely to be muscle bound and strong because fast twitch muscle fibers have a greater potential to hypertrophy than slow twitch fibers. These persons usually perform weight training often and endurance exercise much less since they have more "strength" muscle fibers. This will contribute to less leanness and more of a "mass" build. Again, many will see their low rep \ heavy weight routines are the reason for their muscle mass.

You see, these two groups of individuals will develop their respective physiques inspite of their training protocol, not because of it. However, they make it appear that there is a physique-specific way to strength train when in reality it is their preset genetics that will dictate the results they get. It is important to note that we cannot (at least not yet) alter our muscle fiber types. While it is true that we can change the characteristics of some fast twitch muscle fibers though exercise, we cannot truly change slow to fast and fast to slow.

Regardless of the protocol we use, we all have a tendency to develop a certain kind of physique. Whether we use light weights with high reps or heavy weights with low reps, we will always be prone to develop the physiques that our genes have preset for us. We cannot, through weight training alone, stimulate our muscles to become "cut" or "bulked". Our muscles experience hypertrophy or atrophy. That's it! You can become leaner through increased cardiovascular exercise, proper strength training, and adequate nutrition and recovery. Likewise, you can increase muscle tissue through proper strength training, increased caloric intake, and adequate recovery. However, the strength training performed will need to be proper and not "physique-specific".