Rate of Performance Change in American Female Weightlifters Over Ten Years of Competition.

The purpose of this study was to evaluate the rates of performance change for American female weightlifters over 10 years of competition. Athlete performance results were gathered from the United States Weightlifting open access, results archive, database. Data was delimited to athletes (N ≥ 750) that competed in Youth or Junior Nationals to ensure athletes were <21yrs old at the first recorded competition. Competition results were converted to strength to mass (SM) ratios to control for the effect of bodyweight on performance. Starting with the first competition date, the highest SM for the snatch (SNT), clean and jerk (CJ) and combined total (T), in three month segments for three years, and six month segments over 10 years, were recorded . Observed percentage change in SM and Cohen's d effect size (ES) between each 3-and 6-month segment and the first competition (baseline), for the SNT, CJ and T, was determined. Positive change in rate of performance peaked between time segments baseline-6mo and 7mo-12mo for the SNT (+8.7%, SM 0.68±0.19 to 0.74±0.19, ES=0.34), CJ (+7.7%, SM 0.90±0.24 to 0.97±0.24, ES=0.31) and T (+8.2%, SM 1.57±0.41 to 1.71±0.42 ES=0.34). Total performance increase over 10yrs for the SNT was 27.7% (Year 1 SM 0.68±0.18, year 10 SM 1.13±0.24, ES=0.96), the CJ 22.2% (Year 1 SM 0.90±0.23, year 10 SM 1.40±0.30, ES=0.84), and T 25.0% (Year 1 SM 1.56±0.41, year 10 SM 2.53±0.53, ES=0.91). Observed rates in performance change could be useful for weightlifting coaches as a barometer for evaluating training program outcomes over time.