Table 4.
Heart rate variability (HRV) at time points before and after unfiltered and filtered care rides
| Out-come | Exposure | Mean (SD) | Mean of differences from pre-exposure (SD) | |||||
|---|---|---|---|---|---|---|---|---|
| Pre-exposure a | Immediately Post b | 6 hours post a | 24 hours post c | Immediately Post | 6 hours post | 24 hours post | ||
| RMSSD (ms) | Filtered | 0.095 (0.066) | 0.103 (0.064) | 0.064 (0.042) | 0.082 (0.056) | 0.008 (0.028) | −0.031 (0.043) | −0.011 (0.043) |
| Unfiltered | 0.073 (0.048) | 0.091 (0.051) | 0.056 (0.033) | 0.077 (0.059) | 0.017 (0.050) | −0.016 (0.046) | 0.077 (0.070) | |
| P-value assessing exposure effect d | .5180 | .91056 | .9756 | |||||
| LF (ms2) | Filtered | 1152.6 (1549.4) | 1575.8 (1447.1) | 623.1 (511.1) | 933.5 (1045.4) | 423.2 (1339.5) | −529.6 (1263.5) | −237.6 (1573.3) |
| Unfiltered | 1112.2 (1005.2) | 1432.9 (996.7) | 752.9 (681.2) | 827.9 (795.5) | 281.3 (921.9) | −359.3 (733.0) | −284.0 (663.5) | |
| P-value assessing exposure effect d | .3750 | .2530 | .7847 | |||||
| HF (ms2) | Filtered | 2294.3 (3646.1) | 2453.7 (2993.9) | 1029.9 (1116.5) | 1675.6 (2562.2) | 159.4 (1232.4) | −1264.4 (3220.3) | −540.3 (2110.6) |
| Unfiltered | 1908.1 (2922.2) | 1882.6 (1996.0) | 787.4 (768.2) | 1613.0 (3191.2) | −94.3 (1853.6) | −1120.7 (2560.8) | −222.9 (1456.3) | |
| P-value assessing exposure effect d | .2893 | .2761 | .6482 | |||||
| LF/HF (ms2) | Filtered | 1.2 (1.6) | 1.1 (0.9) | 1.4 (1.2) | 1.0 (0.6) | −0.1 (1.1) | 0.3 (1.7) | −0.2 (1.6) |
| UnFiltered | 1.2 (0.9) | 1.3 (1.1) | 1.3 (0.8) | 1.1 (1.1) | 0.1 (0.9) | 0.1 (0.7) | −0.3 (0.7) | |
| P-value assessing exposure effect d | .3263 | .5061 | .8774 | |||||
| Total Power (ms2) | Filtered | 4644.2 (4699.9) | 7879.1 (8187.1) | 2699.3 (1975.1) | 3891.0 (3658.0) | 3234.9 (7109.1) | −1944.9 (4061.6) | −699.5 (3503.1) |
| Unfiltered | 4391.9 (4976.9) | 6338.7 (5207.0) | 2948.1 (2513.4) | 3652.7 (4980.4) | 1828.7 (3700.2) | −1443.8 (3190.1) | −670.1 (3559.9) | |
| P-value assessing exposure effect d | .2795 | .4105 | .9899 | |||||
| HR (min−1) | Filtered | 60.1 (9.5) | 56.8 (7.9) | 68.9 (12.8) | 61.3 (8.2) | −3.3 (5.0) | 8.8 (8.5) | 0.3 (6.8) |
| Unfiltered | 61.4 (10.2) | 59.4 (9.7) | 70.2 (11.8) | 63.3 (11.8) | −2.7 (7.9) | 8.9 (9.3) | 1.6 (6.8) | |
| P-value assessing exposure effect d | .4087 | .6640 | .5514 | |||||
aN = 20 for filtered; N = 21 for unfiltered; bN = 20 for filtered and unfiltered; cN = 19 for filtered N = 21 for unfiltered; dDerived from mixed-effects linear model, controlling for baseline as a covariate and nested sessions within subject.
Means and Standard Deviations of HRV outcomes at each time point, the changes from pre-exposure and p-values assessing the effect of exposure (unfiltered vs. HEPA-filtered ride) on change in HRV outcomes from pre-exposure baseline to post-exposure time points.