The term "muscle-bound" invokes visions of 300-pound bodybuilders as nimble as the Michelin man and as pliable as a cinder block. In reality, muscle size has nothing to do with flexibility or joint range of motion. If this fallacy were true, one would assume that smaller, longer muscles would be a guarantee of flexibility, yet I've trained many scrawny endurance athletes with hamstrings so short they couldn't touch their ankles.

The fact is, the opposite of muscle-bound may be closer to the truth. A larger muscle has a greater potential for length, just as a thicker rubber band can stretch farther than a thin one of the same length. For example, as we age muscle tissue loss is common. When muscles atrophy, the number of sarcomeres within the muscles decrease, impairing the extensibility and functional capability of the tissue.

Empirical evidence shows that trainees, including the elderly, who increase strength and hypertrophy of the muscles around a joint will improve range of motion specific to the trained area.

Functional zealots argue that bodybuilding-style training will make an athlete slow and uncoordinated but "functional training" will make them fast and agile. This might make the typical functional trainee feel better about their eleven-teen inch pythons, but don't buy it since the empirical evidence suggests otherwise.

The ability to create joint stability or display force is limited by the strength of the muscles involved in the movement.

There's no such thing as nonfunctional muscle tissue. Every muscle is a prime mover of some specific joint pattern, and if any single muscle becomes weak or injured, the corresponding movement pattern will be compromised. Trying to improve the weakness with complex movement patterns (functional exercises) may not achieve the desired results.

According to Muscle Activation Technique founder Greg Roskopf, functional training or integrated exercise will only reinforce compensatory patterns if the weak links aren't first identified and eliminated.

Function isn't determined by the complexity of one exercise – what counts is how you string together each exercise to achieve a desired outcome. Strengthening a muscle within a chain will contribute to the quality of that movement, and the nervous system is well equipped to manage an increase in strength within a specific group of muscles and then incorporate that strength into a fluid movement pattern.

Achieving the musculature of top bodybuilders isn't even possible for 99% of the population. Elite bodybuilders achieve their cartoonish body proportions through a combination of rare genetics, extreme motivation, and in non-tested circles, anabolic steroid use.

During the 1970s and 80's, East Germany won many medals on the backs of juiced female athletes, including 40 gold medals at the 1976 Montréal Olympics. Now if you assume that the drugs improved performance through neural and androgenic changes only, you'd be wrong. The women of the East German swim team were infamous for their husky and blocky bodies, which obviously didn't negate their talents in the pool. The legal, moral, and health ramifications of their actions are another matter entirely.

During baseball's "steroid era" of the late 90's through early 2000s', records were being crushed left and right. Some players achieved dramatic increases in muscle mass and strength from one season to the next, causing suspicious coaches and athletes to suspect that performance enhancing drugs were to blame. When the truth came out, the knee jerk reaction in the athletic world was widespread – big muscles are evil and if you're too muscular, you must be juicing.

This scenario opened the door for a new wave of strength coaches who relied heavily on bands, balls, and balance devices. Their programs didn't look a thing like the programs used by the cheating athletes and coaches. This "new" type of training provided peace of mind for skeptical managers, GM's, and owners. Unfortunately, these so-called cutting-edge programs failed to markedly improve athletic performance.

Regardless of which side of the fence you choose to live, the fact that these "muscle-bound" athletes were kicking major ass is undeniable.

So what can we learn from the drug-era debacle?

Performance enhancing drugs (PED's) have a positive effect on athletic performance. They accelerate recovery, cause muscle hypertrophy of both type I and type II muscle fibers, and increase motor unit recruitment of high-threshold motor units.

The question is, how do we emulate these results through natural methods? While it's safe to say a gap exists between the efficacy of current sports science practices and that of illegal drugs, I can tell you for sure performing low intensity balance exercises while standing on a Bosu-ball isn't helping matters.

I've had great success helping athletes improve performance by focusing on these four tasks:

1. Decreasing injury potential by addressing muscle imbalances
2. Increasing maximal strength and hypertrophy of prime movers of sport or activity
3. Accelerating recovery through nutritional and supplement modifications
4. Maximize endogenous androgens through dietary and lifestyle changes

I recommend pure hypertrophy training for athletes. Maximally developing the prime movers of your sport will increase power and speed potential. I call it bodybuilding for athletes.

To give you a clearer understanding of my training philosophy, here's a program I designed for Brad Hawpe, first baseman for the San Diego Padres.

We used this program for weeks three to five of our 12-week offseason training. (During the first two weeks, the training focus was on muscle balance and range of motion.)

Brad arrived at my facility in mid-November, 2010 weighing 199 pounds at 14.8% body-fat. We completed training on February 9th, 2011 and he weighed 216 pounds at 14% body-fat.

He arrived at spring training a week later weighing 218 pounds.

Day 1: Lower Body – Quad Dominant

Day 2: Horizontal Push/Pull – Arms

Day 3: Lower Body – Hip Dominant

Day 4: Vertical Push/Pull – Arms

Muscle bound, nonfunctional hypertrophy, cosmetic muscle; all calling cards of the insecure trainer who can't get his clients – or himself – big and strong.

While being so big you require your own zip code may not make you a better athlete, there's no evidence to suggest being scrawny does, either. It's time for the popularity pendulum to swing back towards the type of training that is conducive to massive strength and hypertrophy gains and away from the "functional training" paradigm.