We all know that there are some freaky looking powerlifters. That said, powerlifters aren't as muscular as bodybuilders. Name your favorite jacked powerlifter, and we'll show you a bodybuilder who dwarfs him in terms of muscularity.

Granted, many powerlifters carry too much body fat to accurately assess their level of muscularity. For example, here are pictures of Donnie Thompson, Ryan Kennelly, and Benedikt Magnusson. As of mid-2011, these guys are the owners of the world's strongest squat and powerlifting total, strongest bench press, and strongest deadlift, respectively.

Donnie Thompson, Ryan Kennelly, and Benedikt Magnusson

Clearly these guys are beasts, but they're definitely not the most muscular guys on the planet. But if they dropped down to reasonable bodyfat levels they'd likely lose a lot of muscle in the process.

One of the most muscular powerlifters who consistently displays excellent conditioning is Konstantin Konstantinovs.

Konstantin Konstantinovs

He's certainly a freak, but put him next to Ronnie Coleman and suddenly his muscularity isn't as impressive.

Ronnie Coleman

In late 2010, Stan Efferding won the World's Strongest Bodybuilder competition. Stan owns the highest raw powerlifting total in the world, but he's not the most muscular bodybuilder.

Fact is, if you examine pictures of Stan and other powerlifting bodybuilders like Johnnie Jackson and Ben White, you'll notice that all three of these athletes possess mediocre lower body development by bodybuilding standards.

Stan Efferding, Johnnie Jackson, and Ben White

In 1993, Tom Platz, owner of perhaps the biggest wheels in bodybuilding history, entered into a squatting competition with Fred Hatfield (aka "Dr. Squat"), the first guy to squat 1,000 pounds.

Although Tom's legs were much bigger than Fred's, Fred kicked his butt in a one-rep max, hoisting 855 pounds to Tom's 765 pounds. But when they took some plates off the bar and decreased the weight to 525 pounds for a test of lower-body endurance, Tom dusted Fred, performing 23 reps compared to Fred's 11.

Bottom line is, bodybuilders seem better at high reps with a smooth cadence, whereas powerlifters seem more adept at low reps performed explosively.

Mr. Olympia Jay Cutler wrote some very honest and forthright commentary on strength and muscular size in his Muscular Development column in 2010. He listed his all-time best lifts along with his current strength. He used to train with much heavier weights several years back, but he's more muscular now than he was back when he was much stronger. While he still goes heavy, these days he focuses more on quality than quantity.

What Explains the Muscular Differences Between Bodybuilders and Powerlifters?

Many lifters, trainers, and coaches believe that "muscles only know tension." This view is overly simplistic. In reality, a number of factors must be taken into account. What degree of tension? Whatduration of tension? What frequency of tension? What kind of tension? Certainly passive tension isn't as effective as active tension in packing on lean mass.

Many believe that the continuous quest for increased maximal strength is the key to developing massive muscles. But while increased strength is definitely related to increased muscle cross sectional area (CSA), there are multiple adaptations that can boost strength without increasing muscle hypertrophy (Schoenfeld, 2010).

In Neuromechanics of Human Movement, Roger Enoka (Enoka, 2008) lists eight potential neurological areas for non-hypertrophy related strength gains:

• Enhanced output from supraspinal centers as suggested by findings with imagined contractions
• Reduced coactivation of antagonist muscles
• Greater activation of agonist and synergist muscles
• Enhanced coupling of spinal interneurons that produces cross-education
• Changes in descending drive that reduce the bilateral deficit
• Shared input to motor neurons that increases motor unit synchronization
• Greater muscle activation (EMG)
• Heightened excitability and altered connections into motor neurons

Of all of these adaptations, basic coordination between the muscles is the single greatest contributor to non-hypertrophy related strength gains. Along with neurological adaptations, adaptations involving increased stiffness in the tissues that connect from bone to bone (including tendons, extracellular matrix, etc.) can lead to increased force transmission from muscle to bone, and play a significant role in increased strength gains.

Pennation angle. The angle formed by the individual muscle fibers with a muscle's line of action significantly impacts strength irrespective of muscle hypertrophy. Specifically, increased pennation angles appear to have a negative correlation with muscle strength – as pennation angle increases, a muscle's force-generating capacity decreases (Kawakami et al. 1995). Interestingly, studies show that bodybuilders have greater pennation angles than power lifters, potentially due to their training methods (Ikegawa et al. 2008).

Similarly, there are multiple ways in which muscles can grow larger without significantly affecting maximal strength. One such way this can occur is by an increase in non-contractile elements in the muscle cell. Non-contractile hypertrophy includes increases in collagen, glycogen, and other cellular subunits, a phenomenon commonly referred to as "sarcoplasmic hypertrophy" (Siff and Verkhoshansky, 1999).

Since force production is generated by the sarcomeres, sarcoplasmic hypertrophy will have no effect on your 1RM. However, the increased bulk provided by the non-contractile elements will nevertheless produce a tangible impact on muscle size.

An increase in the size of slow-twitch Type I fibers can also affect hypertrophy without having much effect on maximal muscular strength. Type I fibers are endurance-oriented fibers that have limited ability to produce high levels of force (McCardle et al. 2010). However, contrary to what some believe, Type I fibers do increase in size when subjected to a resistance training stimulus, although their hypertrophic capacity is about 50% less than that of fast twitch fibers (Kosek et al. 2006; Staron et al. 1989).

Interestingly, bodybuilders have been shown to have a greater Type 1 cross-sectional area than powerlifters (Tesch and Larsson, 1982). This may well help to explain why Tom Platz displayed greater muscular endurance than Fred Hatfield but wasn't as strong on an absolute basis.

If maximum strength were the end-all-be-all for muscular hypertrophy then powerlifters would be the biggest human beings on the planet, and bodybuilders would employ maximal singles instead of chasing the pump. Simply put, stronger does not necessarily equal bigger, and bigger does not necessarily equal stronger.

What then, makes bodybuilders more muscular than powerlifters?

It's Not Genetics

People naturally gravitate toward what they're good at. In the world of strength training, those with a greater predisposition for strength will be more inclined to become powerlifters (or train like a powerlifter), while those with a greater predisposition for size will be more inclined to become bodybuilders (or train like bodybuilders).

Powerlifting has more to do with leverages, the nervous system, and technique refinement, while bodybuilding has more to do with aesthetics, symmetry, muscularity, and conditioning.

Strength is dependent on plenty of factors, but tendon insertions play a huge role in the ability to exert maximal force. Let's use a biceps curl as an example. Say you're curling a 60-pound dumbbell and you're halfway up at 90 degrees and moving very slowly. To figure out a general estimate of muscle force requirements of the biceps (we'll ignore the other elbow flexors for simplicity), you divide the moment of the resistance arm by the length of the muscle arm.

This means that you multiply the resistance (60 pounds) by the resistance arm (say 15 inches from the elbow to the dumbbell) and then divide it by the muscle arm (say 1 inch from the elbow to the biceps insertion). This gives us 900 inch-pounds (a measure of torque). In this example, the biceps must produce 900 inch-pounds of force.

What happens if the individual's biceps tendon inserts 2 inches away from the fulcrum? Now you divide by 2 instead of 1, which means that the biceps now only has to produce 450 inch-pounds of force to hold a 60-pound dumbbell at a 90-degree elbow angle.

This demonstrates just how advantageous tendon insertions are to external force production – two guys could have equal strength in their biceps but one can lift twice the amount of weight due to advantageous leverages. Torso, arm, femur, and tibia lengths and proportions all play a large role in the display of strength as well.

Obviously the sample size of professional powerlifters and bodybuilders will be skewed. There's also more money involved in bodybuilding. An individual like Ronnie Coleman, who could've excelled at either, might have a proclivity toward bodybuilding due to the larger purses and endorsement opportunities.

Still, this doesn't explain why bodybuilders are more muscular than powerlifters. And one glaring observation is important to consider – when powerlifters start training like bodybuilders, they nearly always gain more muscle!

It's Not Chemical Assistance

Sure, pro bodybuilders take large amounts of performance enhancing drugs, but so do powerlifters. Perhaps professional bodybuilders take higher doses and use a wider array of compounds (such as growth hormone, insulin, IGF-1, T-3, and clenbuterol), but many claim to use moderate doses and stick to the basics, so whether this indeed plays any role is unknown.

A better comparison would be to compare the physiques of natural bodybuilders with those of natural powerlifters. In this case, it's no comparison at all. WNBF bodybuilders such as Layne Norton dwarf WNPF powerlifters such as John Lyras from a hypertrophy standpoint.

Answer – It's How They Train!

Bodybuilders are masters of packing on muscle. While everybody responds uniquely to various exercises, loads, volumes, frequencies, intensities, densities, and durations, there are certain rules that apply to bodybuilding.

If your goal were to maximize muscle development, you'd be a fool to ignore them. While mechanical tension appears to be paramount in hypertrophy stimulation, here are several possible candidates that could explain the superior musculature of bodybuilders over powerlifters.

Higher Reps and Chasing the Pump

Powerlifters generally train in a low rep range (1-5 reps) while bodybuilders tend to favor a moderate rep range (6-12). The adaptations associated with these rep ranges may explain at least part of the hypertrophic differences between these two classes of athletes (Schoenfeld, 2010).

Performing higher reps would theoretically result in a greater hypertrophy of Type 1 fibers. As previously noted, Type 1 fibers are endurance-oriented and thus respond best to longer times under tension. The low-rep training employed by powerlifters simply doesn't allow enough time under tension for significant development of these fibers (Tesch et al. 1984).

Moderate rep training promotes a greater muscle pump. While the pump is often thought of as a short-term training effect, it may result in greater muscle development. Studies show that cellular swelling causes both an increase in protein synthesis and a decrease in protein breakdown (Grant et al., 2000; Stoll et al., 1992; Millar et al., 1997).

It's theorized that an increase in water within the muscle cell – consistent with the mechanisms associated with "the pump" – is perceived as a threat to its integrity.

In response, the cell initiates a signaling cascade that ultimately causes the muscle to grow larger to protect the ultra-structure. In addition, greater occlusion and hypoxia may be associated with higher rep pump-style training, which can induce growth through increases in growth factor production and possibly satellite cell fusion (Vierck et al., 2000).

Moreover, as previously discussed, training in a moderate rep range promotes sarcoplasmic hypertrophy—an increase in non-contractile elements (McDougall, Sale, Elder, & Sutton, 1982; Tesch, 1988). While this in itself manifests as an increased muscle size, it may also promote additional increases in contractile hypertrophy.

Glycogen is hydrophilic (water loving). Each gram of glycogen attracts three grams of water into the muscle cell (Chan et al. 1982). This increased hydration may thus lead to greater myofibrillar growth through cell swelling mechanisms, providing double-duty for increasing hypertrophic gains.

It's also important to take into account the higher levels of poundage (weight x reps) and time under tension (TUT) performed by bodybuilders in comparison to powerlifters. Let's say a bodybuilder performs a bench press routine consisting of 225 x 12, 275 x 10, 315 x 8, and 335 x 6, while a powerlifter does 315 x 5, 365 x 3, 405 x 1, and 415 x 1. Under this scenario, the bodybuilder lifted 9,980 total pounds while the powerlifter lifted 3,490 total pounds.

Assuming 2 seconds per repetition, the bodybuilder accumulated 72 seconds under tension while the powerlifter accumulated 20 seconds under tension – a significant difference!

In a recent study, high reps to failure were shown to be better than low reps to failure for myofibrillar, sarcoplasmic, and mixed protein synthesis (Burd et al. 2010). Although interesting, more research is required as acute protein synthesis doesn't necessarily correlate to greater hypertrophy over time (Mayhew et al. 2009) and previous studies have found very high rep protocols to be suboptimal for increasing muscle growth (Campos et al. 2002).

More total reps also equates to more eccentric contractions, which have been shown to create more muscular damage. There's a large body of evidence suggesting that muscular damage is associated with increased muscle growth, although research is still inconclusive in this area (Brentano et al. 2011; Komulainen et al. 2000; Zanchi et al. 2010).