Can you lift? : Sports Analytics on World Powerlifter's performance
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For readers who only have a vague idea of "powerlifting"
Powerlifting is a strength sport that consists of 3 attempts at maximal weight on 3 lifts:
- Best 3 Benchpresses (upper body strength assessment)
- Best 3 Squats (lower body strength assessment)
- Best 3 Deadlifts (whole body strength assessment)
Unlike Olympic Weightlifting which also requires reflex and technics, "Powerlifting" primarily deals with "Pure Core Strength."
From no equipment to full equipment, powerlifters compete in 4 events:
- Raw: lifting with no or little additional equipment (belts allowed)
- Wraps: lifting with knee/wrist wraps on
- Single-ply: lifting wearing 1 layer of supportive suits
- Multi-ply: lifting wearing 2 or more supportive suits
The data used for this project was obtained from the OpenPowerlifting database (link)
This dataset is the aggregation of time-varying performance records of powerlifting competition contestants and their characteristics, which enables the analysis of performance in powerlifting by different groups and time. Adding robustness in the analysis by dropping records from years with small numbers of observations, the resulting time horizon is from 1988 to 2019.
- How did the characteristics of the contestants change by time?
- The bigger the number of contestants for a country, the better the performance?
- How did equipment affect the performance of male and female powerlifters?
- Has there been a trend of consistent improvement in lifting since 1988 due to the advancement in overall sports science?
1. How did the characteristics of the contestants change by time?
The majority of powerlifting contestants were and are men. However, starting from around 10% of the total contestants in 1988, female participation did increase fluctuating between 20% to 25% from the early 90s to 2015. From 2016, the female participation rate exceeded 30% and is in an increasing trend since then.
- Age Class
Throughout most of the years, the age class of "24-34" has the most contestants, followed by the "20-23" age class. This seems to be a natural result since the age range of "24-34" age class is the widest among all age classes in the data. Also, this result is likely to confirm the orthodoxy that physical strength peaks around 30.
- Competitions by Equipment
Until 1992, Single-Ply (one layer of supportive suit) was virtually the only equipment that was used in powerlifting competitions. After 1993, competitions using Multi-Ply (two or more layers of supportive suit), or even non-equipment(Raw) competitions emerged, but until mid-2000, Single-Ply was the main equipment that dominated powerlifting competitions. However, since 2014, competitions with light or non-equipment became popular, as can be seen below. (plot for 2017)
2. The bigger the number of contestants for a country, the better the performance?
By comparing the country proportion by year and the performances by the countries for the corresponding years, we can check if there is a correlation between the number of country's contestants and the country's performance.
The measurements of performance are the "Average" and "Maximum" of powerlifting weights (Best3Benchpresses, Best3Squats, Best3Deadlifts, and in Total).
The result turns out that while the Maximum powerlifting weights do have some positive correlation with the number of country's contestants, Average powerlifting weights does not.
As the above "Change in Country Proportion" plot presents, the four countries that had the most contestants in 2011 are Ukraine, USA, Russia, and Czech. Those four countries accordingly won the 1st to 4th place in the maximum total powerlifting weights performance, but it was not the case for the average total. This tendency appears across the time horizon.
This is likely to be the effect of outliers. The country average of Total powerlifting weights is affected by both the positive and negative outliers, while the country maximum is only determined by the positive outlier. As the sample size increase likely increases the likelihood of getting an outlier, the country's contestant number increase will generate more positive and negative outliers, in terms of performance, for that country. Thus, that country's maximum weight performance will likely improve as we see in the above plots, while it is not necessarily the case for the average weight performance.
3. How did equipment affect the performance of male and female powerlifters?
4. Has there been a trend of consistent improvement in lifting since 1988 due to the advancement in overall sports science?
Not really some in max not in avg