Similar to Olympic weightlifting, powerlifting is a sport in which lifters compete in divisions based on age, body mass, and sex. In competition, powerlifters attempt to lift maximal (1 repetition maximum) loads in the squat, bench press, and deadlift. In the squat, the lifter begins standing upright with a loaded barbell on the shoulders, then flexes the hip and knee joints until the superior surface of the thigh at the hip is lower than the knee. From this position, the lifter attempts to stand up by extending the knee and hip joints. The bench press is performed with the lifter lying supine on a bench and involves a barbell being lowered to (and paused momentarily on) the chest and then pressed upward so that the elbows are extended and the bar finishes above the shoulders. When performing the deadlift, the lifter will crouch over the barbell and, using powerful knee and hip extension, pull the bar (with straight arms) off the ground until the bar rests across the upper thighs and the lifter is standing upright.
Elite powerlifters may be the strongest athletes in the world (33). For example, current International Powerlifting Federation (IPF) world records reveal that powerlifters in the lighter bodyweight (body mass) men's classes are able to lift more than 5 times their body mass in the squat and deadlift and 3 times body mass for the bench press. Although many factors would contribute to such impressive displays of strength, it appears likely that the anthropometric profile of these lifters is one such factor.
Anthropometric dimensions are likely to influence powerlifting performance in 2 main ways. The first is through the amount of relevant muscle mass because greater absolute loads are typically lifted by lifters with greater fat-free mass (2). Powerlifters like Olympic weightlifters (14,18) may also derive an advantage from being relatively short with short limb segments. This is due to the fact that, because the body is primarily composed of third class levers, the longer the bony segments, the greater the work and torque the lifter is required to produce to lift the barbell. One must, however, be aware that limb proportions that are disadvantageous for one of the powerlifts can be advantageous for another lift. For example, although long arms may reduce bench press performance, this may be beneficial for the deadlift (15,24,25). Therefore, determining the optimal anthropometric proportions for powerlifting appears difficult because each of the lifts has somewhat specific anthropometric requirements.
The relationship between anthropometric characteristics and strength has been investigated using a variety of experimental designs. One approach has been to use correlational and multiple linear regression analyses (15,24,25). These studies have observed that a range of anthropometric variables (e.g., measures of muscle mass, muscular girths, somatotype, segment lengths, etc.) are moderately to highly correlated to, and are able to quite accurately predict, maximal strength in resistance trained athletes such as powerlifters. Studies comparing the anthropometric profile of powerlifters who differed as a function of body mass (2,13,20) or sex (21) have also reported that many of these anthropometric variables differ significantly between these groups, inferring that such characteristics contributed to the between-group differences in strength. No such study appears to have directly compared the anthropometric profile of successful and less successful powerlifters of the same sex and body mass, even though such a design has been commonly used with other sports including golf (22) and Olympic weightlifting (14). Although no formal between-group statistical analyses were conducted, Fry et al. (14) observed that elite junior Olympic lifters had greater (moderate to large effect size) levels of fat-free mass, lower percentage body fat, and a shorter humerus, tibia, and trunk than the nonelite junior lifters. On the basis of the results of Fry et al. (14), it would appear likely that successful powerlifters may also possess a more favorable anthropometric profile than their less-successful counterparts.
This study therefore sought to compare the anthropometric profile of successful (stronger) and less successful (weaker) competitive powerlifters. It was hypothesized that the weaker lifters' reduced powerlifting performance would reflect their lower levels of muscle mass and smaller muscular girths or their longer segment lengths than the stronger lifters.
Experimental Approach to the Problem
The present study used a cross-sectional design to compare the anthropometric characteristics of stronger and weaker powerlifters to gain some insight into the role that anthropometric profile plays in powerlifting performance. Dependent anthropometric variables included measures of body composition, muscular girths, bone breadths, and segment lengths, with most variables expressed in absolute and proportional terms. t-tests and Cohen effect sizes were used to assess the probability and magnitude of the potential between-group differences, respectively.
Fifty-four Australasian and Pacific experienced powerlifters were recruited from a regional-, national-, or international-level powerlifting competition held in New Zealand. These competitions were held in the middle or latter parts of 2002, with all lifters having had considerable periods of specific powerlifting training immediately before the competition. To be eligible for inclusion in this study, all lifters had at least 1 year of current powerlifting experience and were not carrying any recent serious injury that affected their training or competitive performance. Although these competitions involved both men and women, the data presented in this study are only for the men because of the much smaller number of women lifters.
All lifters were categorized as stronger, average, or weaker according to the Wilks score they obtained in the competition at which their anthropometric assessment was performed. The Wilks score is a validated method (32) currently used by the IPF to compare the performance of lifters from varying body weight classes (i.e., to determine the Champion of Champions). Each lifter in the stronger group had a Wilks score greater 410 and those in the weaker group a Wilks score less than 370. On the basis of their Wilks score, all 17 lifters in the stronger group had qualified for the IPF Oceania Championships, with 9 of them also qualifying for the IPF World Championships. In contrast, of the 17 lifters in the weaker group, 13 had only qualified for the New Zealand national championships, with the remaining 4 only qualifying for regional-level competitions. The demographic and performance characteristics of the 2 groups of powerlifters are presented in Table 1.
The IPF has strict rules on the use of performance enhancing drugs and lifting (assistance) equipment. With respect to the use of drugs, none of the powerlifters included in this study had tested positive to any banned substance, including anabolic steroids, in the 2 years preceding data collection. Subjects were informed of the experimental risks and signed an informed consent document before the investigation. The investigation was approved by an institutional review board for use of human subjects.
Powerlifting performance was obtained from the competition at which the anthropometric measurements were taken. The competitions were conducted according to IPF rules, with each lifter getting 3 attempts in the squat, bench press, and deadlift. All of the lifters used assistance equipment such as weight belts and knee wraps, and all but 2 also used squat suits and bench shirts. In accordance with IPF rules, the lifting equipment could only be single-ply and could not be constructed from denim. At the time of data collection, the now commonly used NXG+/NXG Super + materials were not available in New Zealand and therefore were not used by any of the lifters in these competitions.
The anthropometric profile of the powerlifters was obtained following International Society for the Advancement of Kinanthropometry (ISAK) protocols (27). Thirty-seven anthropometric measures were obtained by 4 accredited level II and 2 accredited level III ISAK anthropometrists within 2 days of the athletes competing. These measures included body mass (using Seca scales, Hamburg, Germany), standing and seated height, 6 skinfolds (using a Slim Guide calliper, Creative Health Products, Plymouth, MI, USA), 13 limb/body girths (using a Lufkin metal tape, Cooper Tools, Apex, NC, USA), 9 segment lengths (using a Rosscraft segmometer, Rosscraft, Vancouver, Canada), and 6 breadths (using a Rosscraft anthropometer). Double measures were obtained for all of the 37 anthropometric dimensions except body mass and skinfolds for which 1 and 3 measures, respectively, were taken. In contrast with all other measures, body mass was recorded at the official weigh-in, which, as consistent with IPF rules, was done in the 2 hours immediately before lifting began. Because many lifters may have limited their fluid and food intake in the lead-up to the competition to make “weight,” it is possible that the body mass of the lifters presented in this article would be less than their regular training body mass.
The methods of Carter and Heath (3) were used to determine the somatotype of each lifter. Body fat percentage was estimated from the sum of 4 and 6 skinfolds (35). Fat, residual, skeletal (bone), and muscle mass were calculated using the Drinkwater and Ross (10) equations. Muscle mass was also estimated using equation 4 from Lee et al. (23).
To compare the proportional anthropometry of the 2 groups of powerlifters, 2 methods were used. The first method involved calculating 7 segment length ratios (all expressed as percentages), these being the Brugsch index (chest girth/height), ilio-acromial index (bi-iliac/bi-acromial breadth), Cormic index (sitting height/standing height), arm length-height index (∑ upper arm, forearm, and hand length/height), arm-leg index (∑ upper arm, forearm, and hand length/trochanterion), brachial index (forearm length/upper arm length), and crural index (lower leg length/thigh length). The second method involved normalizing the anthropometric characteristics of each lifter to the Phantom height of 170.18 cm (29-31). The Phantom is a unisex, bilaterally symmetrical conceptual model that was derived from reference data of men and women. The Phantom-Z scores (Zp-scores) for each anthropometric variable were used to demonstrate the number and direction of SDs that each of the 2 groups of powerlifters varied against the Phantom.
Results presented in the text or found in the tables were expressed as group means ± SD. In contrast, the Zp-score data in the figures were all expressed as group means ± SEM according to the methods of Coetzee (5) and De Ridder and colleagues (8). The reliability of all measures was high, with intraclass correlations greater than 0.90 and the technical error of measurement less than 2% for all skinfolds and less than 1% for all bone breadths and limb girths.
Unequal variance independent t-tests were used to determine whether significant differences existed between the weaker and stronger lifters for all variables with the exception of the 3 somatotype components. In accordance with the recommendations of Cressie et al. (7), a multivariate analysis of variance was performed on the somatotype components because it has been shown to have greater statistical power than other tests. Cohen effect sizes (d) were calculated to quantify the magnitude of the between-group differences. In accordance with the revised effect size magnitudes recommended by Drinkwater et al. (9) for sport science research, effect sizes were defined as trivial (<0.2), small (0.2 < 0.6), moderate (0.6 < 1.2), or large (>1.2). Significance was set at p < 0.05 for all statistical analyses.
Power analyses were conducted to determine the number of subjects required for this study. With use of the statistical methods of Hopkins (16) and experimental data for lightweight men (20) and women (21) lifters who were of a similar age, height, body mass, and training experience but dissimilar strength, 22 subjects in total (11 in each group) would be sufficient to show significant between-group differences in a range of anthropometric variables (e.g., body fat percentage, muscle mass, and mesomorphy) with a power of 80% and a risk of type I error of 5%.
Powerlifters' Anthropometric Dimensions
The general anthropometric characteristics of the weaker and stronger powerlifters are presented in Table 2. Overall, both groups exhibited a relatively similar overall anthropometric profile. Effect size analyses indicated that the weaker group had moderately higher values for ectomorphy and percent fractionated bone mass and moderately less muscle mass (calculated using the Lee et al. equation) (23) and absolute and percent fractionated muscle mass than the stronger lifters. However, only the differences in muscle mass and percentage fractionated bone mass attained statistical significance.
The dominant somatotype component for all lifters was mesomorphy, with the individual mesomorphy values ranging from 5.3 to 11.6 for weaker and from 5.9 to 14.8 for stronger lifters. Virtually all lifters were endomesomorphs, the only exceptions being 2 weaker and 1 stronger lifters, who were ectomesosmorphs (Figure 1).
The girth and breadths values for the powerlifters are summarized in Table 3. Stronger lifters had moderately greater flexed upper arm, forearm, chest, and limb girths than the weaker lifters. However, only the difference in flexed upper arm girth achieved statistical significance.
The segment length and length ratios of the powerlifters are presented in Table 4. Moderate effect size differences were observed for 2 variables, with the weaker lifters having longer forearms and a smaller Brugsch Index than the stronger lifters. Only the difference in the Brugsch Index attained statistical significance.
Proportional Anthropometric Dimensions Through the Phantom
Figures 2 to 5 display a range of selected anthropometric dimensions of the weaker and stronger powerlifters as Zp-scores in relation to the Phantom. As seen in Figure 2, there were generally no significant differences in the Zp-scores for body mass or any of the fractionated body compartments (p = 0.174-0.732). The only exception was for the muscle mass Zp-score, which was significantly lower in the weaker group than the stronger group (p = 0.020). The muscular girths of the weaker and stronger powerlifters compared through the Phantom are shown in Figure 3. No significant between-group differences were observed for the head, neck, waist, hip, thigh, or calf girth Zp-scores (p = 0.206-0.719). In contrast, the weaker lifters had significantly smaller flexed upper arm, forearm, and chest girth Zp-scores than the stronger lifters (p = 0.003-0.041). Figures 4 and 5 display the bone breadths and the segment lengths of the weaker and stronger powerlifters compared through the Phantom. No significant between-group differences were observed for any of the bone breadth (p = 0.233-0.648) or segment length (p = 0.449-0.999) Zp-scores.
The present study examined to what extent successful (stronger) and less-successful (weaker) powerlifters may differ in their anthropometric profile. It was hypothesized that the weaker lifters would have lower levels of muscle mass and smaller muscular girths or longer segment lengths than the stronger lifters.
All of the powerlifters were muscular individuals with large muscular girths and bone breadths and relatively average segment length/segment length ratios. These characteristics appear consistent with the literature for powerlifters (2,18,20,24). The mesomorphy values were very high, some perhaps even greater than that reported by Olds (28) in a review on the extremes of human physiques. Three of the 17 weaker lifters and 5 of the 17 stronger lifters had mesomorphy ratings of 10 or more, with the maximum values for individual weaker and stronger lifters being 11.6 and 14.8, respectively. The powerlifters' heightened degree of muscularity was also apparent when examining the upper-body muscular girth Zp-scores, whereby weaker lifters were generally 3 to 4 Zp-scores greater than the Phantom and stronger lifters 4 to 6 Zp-scores larger than the Phantom.
The high level of bone mass and large bone breadths seen in both groups of powerlifters appears advantageous in 2 respects. It may have contributed to their heightened levels of muscular development (24,25) and their ability to withstand the large compressive and shear forces and joint torques characteristic of common powerlifting exercises (11). This ability to withstand these forces and torques appears especially important because any injuries, particularly those to the shoulder, lower back, and knee, may have a negative effect on powerlifting training and competition for a period of time (19).
The relatively short stature and limb lengths (in absolute terms) of both groups of powerlifters may also be performance enhancing (at least in the squat and bench press) because they a) decrease the distance the bar has to be lifted and therefore the amount of muscular work required; and b) improve the mechanical advantage by reducing the length of the resistance lever arm(s). However, the segment length Zp-scores for both groups of lifters was very similar to that of the Phantom. This indicates that the powerlifters' relatively short limbs were primarily a function of their relatively short stature.
No significant differences for any of the segment length measures were observed between the weaker and stronger lifters. This was somewhat unexpected because significant between-group differences in segment lengths have been observed in previous powerlifting (20,21) and weightlifting (14) anthropometry studies. For example, Fry et al. (14) found that elite junior weightlifters' had shorter upper arms, lower legs, and trunks and therefore better leverage than their subelite counterparts. In contrast, closer inspection of the powerlifting studies revealed that the weaker (in absolute terms) lightweight lifters tended to have shorter segment lengths and therefore better leverage than the stronger middleweight and heavyweight (20,21) lifters. This apparently contradictory result is likely to merely reflect the fact that the weaker lifters in these powerlifting studies were significantly shorter than their stronger counterparts. Thus, based on the results of the present study and that of Keogh et al. (20), it would appear that the segment length proportions of the men who compete in powerlifting are relatively similar regardless of their height, body mass, or relative standard. The similarity in segment lengths between the weaker and stronger lifters suggests that their between-group differences in strength can not be explained by differences in the lengths of their levers or the distance the bar needs to be lifted. So what factor(s) may have contributed to the between-group variation in performance?
As hypothesized, the more successful (stronger) powerlifters tended to possess significantly greater levels of muscle mass per unit height and have larger muscular girths than their less successful (weaker) lifters. Such a finding appears consistent with the results for sports in which high levels of muscle mass and strength are important such as rugby league (1), wrestling (4), and Olympic weightlifting (14). These between-group differences could be considered an example of open upper-end optimization (26), in that the greater strength of the stronger powerlifters may be a result of their greater muscle mass and larger muscular girths (2,24).
However, the question remains as to how the stronger lifters had accumulated greater levels of muscle mass per unit height than the weaker lifters. One possibility was that, similar to the findings of Keogh and colleagues (20,21), stronger lifters may have possessed greater levels of bone mass and larger bone breadths. Such anthropometric differences would indicate a larger skeletal structure (frame) that would be advantageous for the accumulation of greater levels of muscle mass (24,25). However, because no significant between-group differences were observed for bone mass or any of the bone breadths in the current study, this possibility can be discounted. The between-group differences in muscle mass and upper-body muscular girths per unit height may therefore reflect differences in a) resistance training/powerlifting experience; b) training practices; c) the use of performance-enhancing agents such as drugs; and d) a genetic profile that provided a greater pretraining degree of muscle mass or a greater hypertrophic response to training (12). None of the lifters tested positive to performance-enhancing drugs in the last 2 years. Although we had no quantitative data on their recent training practices, stronger lifters had significantly more powerlifting experience and a tendency (moderate effect size) for more weight training experience than the weaker group. It is therefore possible that the stronger lifters' greater level of performance and levels of muscle mass and girths per unit height may have reflected in part their greater resistance training/powerlifting experience.
Other limitations of the study concern the sample of powerlifters recruited because a) there were only 17 subjects in each group; b) the stronger group, although comprising lifters who qualified for Oceania or World Championships, could only be considered subelite on the international stage; c) considerable within-group variation in height and body mass existed; and d) even though both groups used similar lifting assistance equipment in their competitions, it was unknown whether they both received similar improvements from the lifting equipment. Future studies in this area should therefore strive to recruit larger samples of powerlifters across a greater variety of standards and investigate the possible interactions between lifting standard, body mass (e.g., light-, middle, and heavy-weight), and sex (2,20). Because each of the 3 powerlifts have somewhat specific anthropometric requirements (15,24,25), future studies may wish to rank the lifters by their performance in each of the separate lifts so to gain further insight into the specific anthropometric characteristics that influence performance in each of the lifts. This may allow the development for each of the lifts a theoretical optimal anthropometric profile. Such data may be particularly useful for the bench press because bench press-only competitions are now becoming increasingly popular.
Another limitation of the current study was that the body composition of the powerlifters was estimated using a variety of equations that all have a number of assumptions (10,23,35). Because all of these assumptions may not hold true for large muscular individuals such as powerlifters, it is possible that some discrepancies could be found between the various approaches used. This is illustrated by the body fat percentages, in that those derived from the ∑4SF and ∑6SF were 3.6-4.7% higher in weaker and 5.1-5.7% higher in stronger lifters than those at of the Drinkwater and Ross (10) values. For a more in-depth discussion of these issues, please refer to Withers et al. (34) and Keogh et al. (20,21). Because resistance training is becoming more commonly used by a variety of athletes and because many of these athletes are becoming increasingly large and muscular, additional methodologic research is required to develop and validate more accurate methods for estimating the body composition of large, muscular individuals (6,17).
Comparing the kinanthropometric characteristics of successful and less-successful athletes within the same sport can assist in the identification of the determinants of human performance. Because the primary between-group anthropometric differences observed in this study indicated that the weaker lifters had significantly less muscle mass and smaller muscular girths per unit height than the stronger lifters, it would appear that these differences may have contributed to the stronger lifters' greater performance. Such a finding suggests that powerlifters need to devote a portion of their training to the development of muscular hypertrophy in the muscle groups most relevant to the 3 powerlifts. Results of this study may also have implications for talent identification in powerlifting because individuals who possess large amounts of muscle mass and muscular girths per unit height and have relatively short segment lengths would appear to have a considerable competitive advantage.
This study was supported by a grant from the Faculty of Health and Environmental Sciences, AUT University, New Zealand. Thanks are given to the member federations of the Oceania Powerlifting Federation, in particular the New Zealand Powerlifting Federation and Powerlifting Australia for their support of the project.
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