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Pediatric Exercise Science, 1993, 5, 347-356 0 1993 Human Kinetics Publishers, Inc.

Relationships of Body Dimensions to Strength Performance

in Novice Adolescent Male Powerlifters

Jerry L. Mayhew, Tom P. McCormick, Fontaine C. Piper, Amy L. Kurth, and Michael D. Arnold

The purpose of this study was to determine the degree to which structural dimensions are related to strength performance in novice adolescent powerlifters. Ninety-nine high school males were measured for 17 anthropometric dimensions and maximal performance in the bench press and deadlift. Body mass and limb circumferences had the highest relationships with lifting performance. Removing the effect of body mass dramatically reduced the relationships between structural dimensions and lift performances. Multiple regression analysis indicated that size and structural dimensions could account for 68.9% and 62.4% of the known variance in the bench press and deadlift, respectively. Body size was the major determinant of weightlifting ability in adolescent male athletes, with structural dimensions playing a lesser role in determining success.

It is a widely accepted axiom that particular body types or body builds generally exhibit greater success in certain competitive weightlifting events. In Olympic weightlifting the snatch and clean and jerk are similar in their performance demands and are dominated by the shorter, more mesomorphic body builds (3,4). In powerlifting the lifts used are the bench press, squat, and deadlift, and the distinction among body types is less apparent since the three lifts are not closely related biomechanically. Individuals with short arms and large chest circumferences may excel in the bench press (15, 16), while shorter individuals with a lower leg 1ength:height ratio are considered better squat lifters (16). Individuals with longer arm lengths relative to leg lengths may have better deadlifting ability.

Despite the popularity of these suppositions, little research has been con- ducted to verify the existence of anthropometric predispositions to success in powerlifting. Knowledge regarding the degree to which structural dimensions

Mayhew: Human Performance Lab, Northeast Missouri State U., Kirksville, MO 63501; and Physiology, Kirksville Coll. Osteopathic Medicine. McCormick: P.E. Dept., Clinton Jr. High School, Clinton, IA 52771. Piper: Human Performance Lab, NMSU; and Anatomy, Kirksville Coll. Osteopathic Medicine. Kurth: Physical Therapy, Providence- St. Margaret Health Ctr., Kansas City, KS 661 12. Arnold: Wellness/Fitness Lab, Clark Coll., Vancouver, WA 98663. Request reprints from J.L. Mayhew at NMSU.

348 - Mayhew, McCormick, Piper, Kurth, and Arnold

are related to strength performance might be beneficial to young athletes who engage in weight training activities and coaches who supervise them. If particular structural characteristics are significantly related to lifting performance, coaches can select athletes with anthropometric dimensions more suited to perform these strength maneuvers to enhance their chances for competitive success. In addition, if structural dimensions limit the potential to perform certain weightlifting exercises, it might help explain the differences in success noted among diverse body builds during the adolescent years. If body dimensions are not highly related to lifting performance, the structural diversity often seen among young athletes may be disregarded as a factor affecting lifting performance.

The purpose of this study was to determine the relationships between structural dimensions and strength performance among novice male high school athletes during a powerlifting competition.

Methods

Ninety-nine adolescent male athletes attending an interscholastic powerlifting contest volunteered to serve as subjects. Athletes, coaches, and parents gave their informed consent for participation. All of the subjects had competed throughout the year in football, wrestling, and/or track and field, and each had performed strength training exercises for a minimum of 2 months preceding measurement. Since none of the subjects had competed in more than two other powerlifting competitions, they were considered novices relative to this sport.

Five experienced examiners (>1 yr of training) performed all anthropometric determinations prior to the lifting competition. Each examiner had been instructed in proper measurement techniques to ensure consistency and performed only certain designed measurements.

Muscle circumferences were taken around the arm, chest, hips, thigh, and calf (2). Arm circumference was taken around the maximum girth of the flexed right arm. Chest circumference was measured at midexpiration at the level of the nipples. Hip circumference was measured around the maximum girth of the gluteal muscles with the subject's feet together and weight evenly distributed. Thigh circumference was measured around the contracted muscle of the right leg midway between the hip and knee joints. Calf circumference was measured around the largest girth of the flexed right foreleg. All circumferences were measured in triplicate using a cloth tape with a Gullick handle, and the average was used to represent each site. Muscle cross-sectional area (CSA) for the arm and thigh were estimated from the formula given by Gurney and Jelliffe (6):

- [cir (cm) - n: . skf (cm)I2 CSA (cm ) -

4 . n

Skeletal dimensions included standing and sitting height, arm and forearm lengths, bench press drop distance, and deadlift pull distance. Standing and sitting heights were determined using a wall stadiometer (13). During the sitting height measurement the subject was required to sit erect and place the entire back flat against the stadiometer. Leg length was estimated as the difference between standing and sitting heights. Leg length ratio (expressed as a percent) was determined by dividing leg length by height. Arm length was measured from the acromion process to the olecranon process with the arm flexed 90' at the elbow

Adolescent Mate Powerlifters - 349

(13). Forearm length was measured from the olecranon process to the styloid process (13). Arm:leg ratio (expressed as a percent) was calculated by dividing total arm length (arm + forearm) by leg length. Limb measurements were made on the right side of the body using a broad-blade wooden caliper.

Bench press drop distance was determined by having the subject assume the supine posture on a bench and grasp an unloaded Olympic bar at the same position he used for the lift. The distance from the bar to the midpoint of the sternum was measured with a cloth tape. Deadlift pull height was measured from the bar to the floor while the subject was in the erect position. Pull height was corrected for the height of the bar above the floor caused by the largest weight plate (20.5 kg). All measurements were made in triplicate, and the average was used to represent each variable.

Skinfolds were measured in triplicate at the triceps, subscapular, chest, suprailiac, thigh, and calf sites according to the procedures given by Hamson et al. (7). The average of the three measurements at each site was used for analysis. The sum of the six slunfold sites ( 6 s ~ ) was used to represent body adiposity.

All subjects performed the bench press first during the morning competition. After a short break (1-1.5 hrs), the deadlift competition was completed. The squat lift was not used because of the coaches' concern about the potential danger to young participants. Each lifter was given only three attempts to achieve his one-repetition maximum (1-RM) for a particular lift. Contestants were free to select their entry weight and subsequent increments, but no contestant could reduce the weight once it was selected.

In the bench press the subject lifted the bar from the support rack and then lowered it slowly to chest level. After a signal from the judge, the lifter returned the bar to full arms' length and was assisted in placing it on the rack. His back was required to remain in contact with the bench throughout the lift.

In the deadlift, the subject typically assumed an alternate grip on the bar. The back remained relatively straight throughout the maneuver, and the leg and hip muscles were used to lift the weight. All contestants wore a lifting belt during the competition. A judge determined whether the lift was successful.

Pearson product-moment correlations were computed among all variables to determine interrelationships. The partial correlation technique was used to remove the influence of body mass from the relationship between lift performance and dimensional variables. A principal components factor analysis was used to group those variables with the highest common associations in order to obtain a more favorable subject:variable ratio for multiple regression analysis. Forward inclusion, stepwise multiple regression analysis was used to determine the best variables to estimate each lift performance from among the ones selected during the factor analysis. The standardized regression coefficients were used to evaluate the relative contribution of significant variables to the explained variance of each lift.

Results

The physical characteristics of the subjects are shown in Table 1. Generally, the relationships between structural dimensions and lift performance were comparable for the bench press and deadlift (Table 2). Body mass was the only dimensional variable to account for more than 50% of the explained variance in strength, and then it was only for the bench press. Arm and chest circumferences were the


Table 1

Physical and Performance Characteristics of the Subjects (N = 99)

Variable Mean SD Range

Age (yrs) Height (cm) Body mass (kg) ~ S K F (mm) Arm circum. (cm) Chest circum. (cm) Hip circum. (cm) Thigh circum. (cm) Calf circum. (cm) Arm CSA (cm2) Thigh CSA (cm2) Arm length (cm) Forearm length (cm) Leg length (cm) Armlleg length x 100 Leg lengthlheight x 100 Drop distance (cm) Pull height (cm) Bench press (kg) Deadlift (kg)

next highest correlates with strength performance. All of the muscle circumference measurements (r > 0.69) and skeletal lengths (r > 0.55) were significantly inter- related.

Because of the high correlation of body mass with each lift, its effect was removed by expressing the lift relative to body mass and by the partial correlation technique (Table 2). Expressing bench press strength relative to body mass reduced the number of significant correlations with structural dimensions from 14 to 3. Expressing deadlift strength relative to body mass reduced the number of significant correlation coefficients with structural dimensions from 14 to 12, although many of the correlations became negative. When body mass was controlled by the partial correlation technique, only 5 correlations between structural dimensions and bench press performance remained significant, and only 6 were significant for deadlift.

A forward inclusion, stepwise multiple regression analysis using the most representative anthropometric variables was used to predict strength performance for each lift (Table 3). Five significant variables accounted for 68.9% of the explained variance in the bench press. Of these five variables, body mass (70.7%) accounted for the largest proportion of the explained variance. The ~ S K F (14.4%), forearm length (6.3%), arm CSA (5.1%), and age (3.5%) accounted for substantially less of the explained variance. Predicting the bench presslkg resulted in

unted

Adolescent Male Powerlifters - 351

Table 2

Correlations Between Anthropometric Dimensions and Strength Performances in Adolescent Male Powerlifters (N = 99)"

Variable

Bench press Deadlift

Absolute kgb BMC Absolute kga BMC

Age (yrs) Height (cm) Body mass (kg) ~ S K F (mm) Arm circum. (cm) Arm CSA (cm2) Chest circurn. (cm) Hip circum. (cm) Thigh circum. (cm) Thigh CSA (cm2) Calf circurn. (cm) Arm length (cm) Forearm length (cm) Leg length (crn) Leg lengthlheight x 100 Armlleg length x 100 Drop distance (cm) Pull distance (cm)

"r= 0.25 significant at p < 0.01 ; bStrength performance divided by body mass; CEffect of body mass removed using the partial correlation technique.

for only 34.8% of the explained variance (Table 3). Of the four significant variables selected to estimate bench presskg, arm circumference (36.1%) and ~ S K F (33.5%) were comparable in their contributions to the explained variance, with forearm length (16.9%) and age (13.5%) adding lesser amounts.

Four significant variables accounted for 62.4% of the explained variance in the deadlift (Table 3). Again, body mass accounted for the major proportion of the explained variance (71.2%), with the ~ S K F (16.9%), thigh circumference (6.7%), and age (5.2%) contributing substantially less. Expressing the deadlift relative to body mass reduced the overall explained variance to 44.9%. Of the three significant variables selected to estimate deadliftkg, 6sm (68.1%) contributed substantially more than did age (18.9%) or height (13.0%).

Discussion

The height and body mass of the current subjects were within 2-5% and 5-15%, respectively, of adolescents of similar age (9, 11, 20, 21, 22). There were no data in the literature for comparison with the strength measures used in this study. However, the correlation coefficients between body mass and various


Table 3

Multiple Regression Analysis to Predict Bench Press and Deadlift Performance in Adolescent Male Powerlifters (N = 99)

Variable

Regression coefficients Bench press Deadlift

Absolute Relative Absolute Relative

Height (cm)

Body mass (kg)

Arm circum. (cm)

Arm CSA (cm2)

Thigh circum. (cm)

Forearm length (cm)

Intercept Rb R2 x 100" SEE^

aValues in parentheses are standardized regression coefficients; bR = 0.25 significant at p < 0.01 ; CCoefficient of determination; dStandard error of estimate in kg for absolute strength measures, and in kglkg BM for relative strength measures.

other strength measurement techniques reported in other studies (e.g., isometric, isokinetic, and Olympic weightlifting) were comparable to those noted in the current study (1, 5, 19).

The results of this study indicate that body mass was the most obvious factor contributing to the amount of weight lifted by adolescent athletes performing the bench press and deadlift maneuvers. Removing the effect of body mass by two widely used techniques reduced the number of significant correlations between structural dimensions and lifting performance, especially in the bench press. Expressing lift performance relative to body mass reduced the magnitude of the correlations more between bench press and the structural dimensions than it did for the deadlift. In fact, the direction of most of the correlations between deadlift and structural dimensions was reversed to become negative when lift performance was express relative to body mass. This would generally suggest that smaller athletes had greater relative strength performance, a fact that coincided with the results noted in older collegiate strength athletes (15, 16). The high relationship


between body mass and the structural dimensions (r > 0.79) probably explained the biggest part of the reduction in most of the correlations.

These current results generally agreed with those of Watson and O'Dono- van, who used isometric grip and back strengths to evaluate 16- to 18-year-old male physical education students (22). The authors noted that holding body mass constant reduced many of the correlation coefficients between an isometric strength index (right and left grip plus back strength) and body dimensions. The values were approximately equal in magnitude to those noted in the current study. However, Watson and O'Donovan (22) concluded that strength was more a function of segmental component size rather than overall body size, based on the results of their multiple regression analysis which selected bone widths, arm circumference, and mesomorphic body build to predict strength (R = 0.85). They further pointed out that if sufficient range was achieved in the data, overall size becomes irrelevant in the determination of strength.

In the current study, holding the influence of body mass constant by the partial correlation technique resulted in significant but weak relationships between arm size and bench press and between thigh size and deadlift, with none of these correlation coefficients accounting for more than 12% of the explained variance in lift performance. Some of the contradiction between the two studies might be attributable to the difference in the strength measurement technique used (isometric vs. dynamic).

Another point worth noting relative to the influence of body size is the fact that the current as well as previous studies indicate, upon initial observation, that body fatness is positively related to strength performance. That is, greater body fat appears to be positively associated with greater strength. However, the positive relationships between body mass and both absolute and relative body fat exert an influence on this relationship (15, 16, 22). Removing the effect of body mass in the current study revealed negative but weak correlations between body fat and both strength performances (Table 2) which were similar to those noted for collegiate strength athletes (15, 16). However, the correlation noted by Watson and O'Donovan (22) between isometric strength measures and relative fat content (r = -0.68) was substantially stronger and very similar to that found in the current study between ~ S K F and deadliftkg.

McLeod et al. (18) have reported that body fat was negatively related to relative strength performance when the latter was measured from pull-up and dip work output, but not to absolute strength from a grip strength test. Thus the effect of body fatness on strength performance may be affected by test method, means of expressing strength performance, variability in the subject sample, and level of training among individuals.

The reason the two strength performances were affected similarly among the current adolescent subjects when body mass was controlled could be due to the high correlation between the two lifts (r = 0.80). In a sample of college football players the bench press and deadlift had only 35% common variance between them, indicating that the lifts were evaluating separate strength components (16). Hortobagyi et al. (10) have stated that an r > 0.71 is required among different strength procedures in order for them to be classified as a "general strength component," since this would indicate more than 50% common variance between the measurements. Since the two lifts shared 64% common variance between them in the current study, it suggests a general strength factor among


high school athletes. Thus, young individuals who are strong in one muscle group or lift might well be strong in other lifts as well. This is contradictory to the earlier work of Jackson et al. (12) in untrained college men and to our recent work in college athletes (15, 16). The question of the generality of muscular strength measurements among adolescents may warrant further investigation.

Other differences were noted between the current adolescent subjects and the more extensively trained college athletes (15, 16). Most noteworthy was the effect of removing the influence of body mass on the relationships between structural dimensions and bench press performance. Among the college football players (16), holding body mass constant decreased the correlation coefficient between arm circumference and bench press only slightly (r = 0.71 to 0.54) and increased the correlation coefficient between arm length and bench press (r = -0.10 to -0.43). In the adolescent athletes, holding body mass constant dramatically reduced the correlation coefficient between arm circumference and bench press but had little effect on the correlation coefficient between arm length and bench press (Table 2).

When considered in conjunction with greater age, more body mass, greater arm size, and lower body fat, shorter forearm lengths contributed only slightly (6.3%) to greater lift performance in the bench press among the current subjects. Perhaps the more experienced college athletes had refined their bench press technique to take advantage of the shorter arm length in lowering the bar to the chest (17). Previous studies have noted that shorter, stockier individuals tend to perform better in weightlifting events (2, 3, 8, 14, 15, 16). In those studies, however, as in the current findings, the effect of limb length was small when compared to the effect of body mass.

The multiple regression analysis to predict deadlift again illustrated the dominance of overall size in strength performance, since body mass accounted for more than twice the combined effect of greater age, less body fat, and larger thigh size. However, the prediction of deadliftkg magnified the negative effect of body fatness on total body strength performance. This finding coincided with previous analysis of deadlift performance in more experienced athletes (16). Furthermore, a shorter leg length and a smaller leg 1ength:height ratio have both been shown to have a positive effect on deadlift performance in older athletes (15, 16), which was not evident in the current subjects (Table 2).

Previous analysis of powerlifting performance has revealed that the fewer the number of joints and muscle groups involved in the strength maneuver, the greater the potential of limb dimensions for predicting performance (15, 16). In adolescent athletes, dimensional features appear to be equally effective in estimat- ing strength performance from various lifts. The lack of experience in the techniques of lifting heavy weights could play a part in this result. Perhaps regional limb dimensions would have a greater influence on strength in more highly skilled and/or experienced adolescent powerlifters. It may well be that refinement of biomechanical techniques makes the performance in certain weightlifting maneuvers somewhat more dependent on segmental body structure.

In conclusion, overall body size appears to be the key determinant of performance in strength maneuvers such as the bench press and deadlift among adolescent athletes. Limb circumference and length play a lesser role in dictating strength performance in these younger subjects. Thus, adolescent athletes who train with weights are likely to be limited more by their body mass than by


structural dimensions in their ability t o handle heavy barbells. Furthermore, adolescent athletes may have a general strength component that can be measured by either the bench press or deadlift.

References

1. Bancroft, G.A., S.J.H. Biddle, and S.C. Brown. Handicapping formulae in Olympic weightlifting: A reappraisal for schoolboy weightlifters. Res. Q. Exer. Sport 58:388- 391, 1987.

2. Callaway, C.W., W.C. Chumlea, C. Bouchard, J.H. Himes, T.G. Lohman, A.D. Martin, C.D. Mitchell, W.H. Mueller, A.F. Roche, and V.D. Seefeldt. Circumferences. In: Anthropometric Standardization Reference Manual, T.G. Lohman, A.F. Roche, and R. Martorell (Eds.). Champaign, IL: Human Kinetics, 1988, pp. 39-54.

3. Carter, J.E.L., S.P. Aubry, and D.A. Sleet. Somatotype of Montreal Olympic athletes. In: Physical Structure of Olympic Athletes, Part I: The Montreal Olympic Games Anthropometrical Project. Medicine and Sport, Vol. 16, J.E.L. Carter (Ed.). 1982, pp. 53-80.

4. Elnashar, A., and J.L. Mayhew. Physical characteristics of the Egyptian national weightlifting teams. J . Appl. Sport Sci. Res. 4:109, 1990. (Abstract)

5. Gilliam, T.B., S.P. Sady, P.S. Freedson, and J. Vallanacci. Isokinetic torque levels for high school football players. Arch. Phys. Med. Rehab. 60:llO-114, 1979.

6. Gurney, J.M., and D.B. Jelliffe. Arm anthropometry in nutritional assessment: Nomo- gram for rapid calculation of muscle circumference and cross-sectional muscle and fat areas. Amer. J. Clin. Nutr. 26:912-915, 1973.

7. Harrison, G.G., E.R. Buskirk, J.E.L. Carter, F.E. Johnston, T.G. Lohman, M.L. Pol- lock, A.F. Roche, and J. Wilmore. Skinfold thicknesses and measurement techniques. In: Anthropometric Standardization Reference Manual, T.G. Lohman, A.F. Roche, and R. Martorell (Eds.). Champaign, IL: Human Kinetics, 1988, pp. 55-70.

8. Hart, C.L., T.E. Ward, and J.L. Mayhew. Anthropometric correlates with bench press performance following resistance training. Sports Train. Med. Rehab. 2339-95, 1991.

9. Holmes, J.R., and G.J. Alderink. Isokinetic strength characteristics of the quadriceps femoris and hamstring muscles in high school students. Phys. Ther. 64914-918, 1984.

10. Hortobagyi, T., F.I. Katch, and P.F. Lachance. Interrelationships among various measures of upper body strength assessed by different contraction modes: Evidence for a general strength component. Eur. J. Appl. Physiol. 58:749-755, 1989.

11. Housh, T.J., G.O. Johnson, and D.J. Housh. Muscular power of high school wrestlers. Ped. Exer. Sci. 3:43-48, 1991.

12. Jackson, A., M. Watkins, and R.W. Patton. A factor analysis of twelve selected maximal isotonic strength performances on the universal gym. Med. Sci. Sports Exer. 12:274-277, 1980.

13. Martin, A.D., J.E.L. Carter, K.C. Hendy, and R.M. Malina. Segment lengths. In: Anthropometric Standardization Reference Manual, T.G. Lohman, A.F. Roche, and R. Martorell (Eds.). Champaign, IL: Human Kinetics, 1988, pp. 9-26.

14. Mayhew, J.L., T.E. Ball, T.E. Ward, C.L. Hart, and M.D. Arnold. Relationships of structural dimensions to bench press strength in college males. J. Sports Med. Phys. Fitness 31:135-146, 1991.

15. Mayhew, J.L., F.C. Piper, and J.S. Ware. Relationship of anthropometric dimensions with strength performance in resistance trained athletes. Indian J . Phys. Educ. Rec. Sports. In press.


16. Mayhew, J.L., F.C. Piper, and J.S. Ware. Anthropometric correlates with strength performance among resistance trained athletes. J. Sports Med. Phys. Fitness. In press.

17. McLaughlin, T.M., and N.H. Madsen. Bench press techniques of elite heavyweight powerlifters. Nut. Strength Cond. Assoc. J . 6:44, 62-65, 1984.

18. McLeod, W.D., S.C. Hunter, and B. Etchison. Performance measurement and percent body fat in the high school athlete. Am. J. Sports Med. 11:390-397, 1983.

19. Parker, M.G., R.O. Ruhling, D. Holt, E. Bauman, and M. Drayna. Descriptive analysis of quadriceps and hamstrings muscle torque in high school football players. J. Orthop. Sports Phys. Ther. 5:2-6, 1983.

20. Thorland, W.G., G.O. Johnson, T.G. Fagot, G.D. Tharp, and R.W. Hammer. Body composition and somatotype characteristics of junior Olympic athletes. Med. Sci. Sports Exer. 13:332-338, 1981.

21. Thorland, W.G., G.O. Johnson, T.J. Housh, and M.J. Refsell. Anthropometric characteristics of elite adolescent competitive swimmers. Human Biol. 55:735-748, 1984.

22. Watson, A.W.S., and D.J. O'Donovan. Factors relating to the strength of male adolescents. J. Appl. Physiol. 43:834-838, 1977.

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