(42) MUSCLE FIBER CHARACTERISTICS OF A WEIGHTLIFTING WORLD CHAMPION AND WORLD RECORD HOLDER – A CASE STUDY

The sport of weightlifting (i.e., snatch + clean & jerk) involves lifting very heavy loads extremely rapidly, resulting in very high barbell power production.

Purpose: The purpose of the present study was to characterize the muscle fiber characteristics of an elite female world champion weightlifter who also held the world record in the snatch lift.

Methods: A percutaneous muscle biopsy from the mid-belly of the right vastus lateralis m. was obtained from an actively competing elite female weightlifter (age = 24 yrs, height = 1.53 m, BW = 50 kg, relative 1 RM snatch = 1.69 x BW, relative clean & jerk = 1.98 x BW, 7-time world championship medalist, 10-time national champion, national and world record holder). Serial sections of tissue (n = 615 fibers, >50 fibers/major fiber type) were fiber typed via mATPase histochemistry using the methods of Brooke & Kaiser and modified by Pette & Staron, which has been validated with sectioned single fiber MHC profiles (Staron 1991). Additional tissue sections were homogenized and lysed in a b-mercaptoethanol solution and heated at 60° C for 10 min. SDS-PAGE was used to determine relative expression (%) of MHC isoforms, which are highly related (r = 0.90) to relative fiber type cross-sectional area (Fry et al. 1994). Data from previously reported national- and international-level male weightlifters are reported for comparative purposes (Fry et al. 2003).

Results: Fiber type percentages for the female case study weightlifter were as follows; I = 35.2%, IIA = 64.8%, IIX = 0.0%, with no evidence of any hybrid fibers (i.e., types IC, IIC, IIAC or IIAX). Previously reported high-level male weightlifters (n=6) exhibited the following % fiber types; I = 46.5±2.3%, IC = 1.2±0.7%, IIC = 0.6±0.2%, IIAC = 0.0±0.0%, IIA = 46.5±2.7%, IIAX = 2.8±0.7% and IIX = 2.4±2.0%. Relative MHC expression for the female case study was as follows; MHC I = 28.0%, MHC IIa = 72.0% and MHC IIx = 0.0%. The comparison male weightlifters exhibited the following %MHC; MHC I = 34.6±2.9%, MHC IIa = 64.0±2.3%, MHC IIx = 1.4±1.4%. All values for the female weightlifter were outside the 95% CI for the comparison male weightlifters.

Discussion: To the authors’ knowledge, this is the first analysis of this kind from an elite weightlifter’s muscle biopsy while actively performing at the highest level of their sport. Fiber type % and %MHC data for the present case study female weightlifter were significantly different from the comparison group of male high-level weightlifters. This may explain in part the superior relative lifting performances of the present case study lifter, despite being the opposite sex. Other reports on elite female weightlifters (Serrano et al. 2019) have indicated somewhat similar fiber characteristics, although different muscle analysis methods were used. It is speculated that an additional contributing factor to performance for the present case study, although not measured, may be the large muscle volumes of some of the primary movers for weightlifting, the quadriceps muscles in this case. Regardless, these data suggest that extreme weightlifting capabilities are due in part to a high percentage of IIA fibers, along with a large relative cross-sectional area for the IIA fibers as indicated by the %MHC data. Practical Applications: To enhance weightlifting performance, coaches may want to prescribe training protocols that induce preferential hypertrophy of the type IIA fibers, and shift fiber types to IIA.

Acknowledgements:

This project was funded in part by USA-Weightlifting and by the Clara Wu and Joseph Tsai Foundation.