The variability of estimated VO2Max derived from 20MSFT scores in Australian law enforcement recruits: implications for occupational standards

Activity: Talk or presentationOral presentation


Background: The 20m Progressive Shuttle Run Test (20MSFT) is commonly utilized by law enforcement to measure aerobic fitness, and to provide estimates of VO2Max. These measures are an important occupational variable, with aerobic fitness linked to injury risk, employment status, occupational performance, and long-term health. However, there are a multitude of predictive equations derived from 20MSFT results to provide estimates of VO2Max. The extent of variability in these estimated values has not been quantified within law enforcement. This is consequential for comparisons between differing agencies, and in establishing normative data. Therefore, this study aims to compare the variability in estimated VO2Max scores from commonly applied 20MSFT predictive equations. Methods: Data from 1,094 law enforcement recruits (male n = 741, 25.2 ± 6.3 years; female: n = 353, 25.6 ± 5.6 years) who completed a 20MSFT were retrospectively analyzed, with 20MSFT scores transformed into estimated VO2Max using six different predictive equations. A mixed factor repeated-measures ANOVA was used to determine the differences between VO2max equations, and between male and female recruits. Spearman (rs) correlations examined the strength of the relationship between the VO2max equations. Results: VO2Max equations showed small to very strong correlations with (p < 0.001; rs = 0.32 – 0.99). Specifically, there were very strong positive (rs >0.93) relationships between the Leger & Lambert, Leger et al., and Ramsbottom et al., equations, with the Stickland et al. and Aandstad et al. equations demonstrating the lowest correlation coefficients compared with the others. However, there were statistically significant differences in VO2Max values between each predictive equation evaluated (p < 0.001; d = 0.25 – 1.53). Differences in VO2Max values between male and female recruits (p= <0.001, r= 0.55), with males exhibiting a higher VO2max than females (mean difference = 4.10 ml·kg·min-1 [CI= 3.56—4.10], p= <0.001, d = 0.45) were also observed.Discussion: The findings indicate considerable variability ofVO2Max values derived from the same 20MSFT scores when utilizing differing predictive equations. This suggests either a standardised conversion approach should be developed and recommended for law enforcement agencies, or the use of raw 20MSFT variables (e.g., shuttles/distance completed) should be preferred to measure and apply results from aerobic fitness tests if standardized approaches are not developed. Future research should seek to establish raw score 20MSFT normative data in male and female recruits within Australian law enforcement agencies. Conflict of interest statement: My co-authors and I acknowledge that we have no conflict of interest of relevance to the submission of this abstract.
Period23 Oct 2021
Event title2021 SMA e-Conference
Event typeConference