Table 5.

The association between cardiorespiratory fitness (VO_2max) and relative aerobic load (%HRR) at work—stratified by age

Age group (years)	Estimates [95% CI]
	≤ 37 (n = 111)	38–45 (n = 121)	46–51 (n = 112)	≥ 52 (n = 95)
Mean %HRRa	−0.29 [−0.44 to −0.15]	−0.37 [−0.49 to −0.24]	-0.45 [−0.60 to −0.31]	−0.28 [−0.50 to −0.07]
Max %HRRa	−0.39 [−0.60 to −0.17]	−0.45 [−0.66 to −0.25]	−0.45 [−0.70 to −0.20]	−0.42 [−0.69 to −0.16]
> 30%HRRb	−1.5% [−2.1 to −0.8%]	−1.9% [−2.5 to −1.3%]	−2.6% [−3.4 to −1.7%]	−1.7% [−2.8% to −0.5%]

Bold indicates statistically significant effects (p < 0.05)

HRR heart rate reserve, Max %HRR maximum % of HRR at which an individual has spent at least 1 min at or above during work, >30%HRR percentage of time spent at work above 30% HRR

^aEstimates are β-coefficients

^bEstimates are the absolute change in the proportion of time spent at work above 30%HRR