Validation of the Recovery Heart Rate to Estimate Maximum Oxygen Consumption in the Six Minute Walk Test
The prediction of maximum oxygen consumption (VO2max) was made based on heart rate (HR) in submaximal exercise by developing multiple equations to estimate it through submaximal intensity tests using a range of ergometers. The objective was to draw up equations to estimate VO2max from the recovery HR (rHR) obtained in the six minute walk test (SMWT) in Physical Education students (PES) at a university in Concepción in Chile and in Physical Exercise Science undergraduate students (PESUS) at a centre in Barcelona in Catalonia.The research consisted of four studies using a quantitative approach, a non-experimental and cross-sectional design with a descriptive and correlational scope and a non-probabilistic sample. In the first study the PAR-Q, SMWT and Multi-Stage Fitness Test (MSFT) questionnaire was used with 127 PES aged 21. In the second, the same test-retest tests were used on three different days, adding an informed consent form with a sample of 17 PES aged 22. In the third study and in addition to the abovementioned tests, the Bruce treadmill test was used in a second session with direct measurement of VO2max in 20 PES aged 22 who gave their written consent. The fourth investigation involved 28 PESUS aged 21 who also signed an informed consent form to perform the SMWT and MSFT; in the latter VO2max was directly measured. The variables of interest were rHR in the SMWT and VO2max in the MSFT and the Bruce test. Normality, ANOVA and correlation (p < 0.05) tests were conducted as part of the analysis using the SPSS program version 19.In the first investigation a correlation of rho = –0.44 (p<0.01) was found between rHR (SMWT) and VO2max (MSFT). In the second study there were no significant differences between measurements one, two and three in rHR and VO2max with a correlation of r = –0.72 (p < 0.01). In the third investigation there was a correlation of r = –0.657 (p = 0.002) between rHR and the VO2max measured in the Bruce test, and the resulting equation wasy (VO2max) = 92.468 – (0.278 * rHR 20 sec.) with a standard error of the estimate (SEE) of 7.17 ml · kg–1 · min–1. In the fourth study the correlation was r = –0.479 (p = 0.01) between rHR and VO2max measured in the MSFT, and the equation was y = 74.52 – (0.154 * rHR 30 s) and an SEE of 5.55 ml · kg–1 · min–1. It is concluded that the equations predict the VO2max considering that the SEE for both of them is higher than the one found in the available literature.