Table 2.

Commonly used methods to determine aerobic exercise intensity (75).

Intensity level	%HRR, %VO2R	%HRmax	%VO2max	RPE (0–10)	Talk test
Low	<30	<57	<37	Very easy (<3)	Can talk and sing
Somewhat low	30 ~ 39	57 ~ 63	37 ~ 45	Very easy to easy (3 ~ 4)
Moderate	40 ~ 59	64 ~ 76	46 ~ 63	Easy to somewhat hard (5 ~ 6)	Can talk but cannot sing
High	60 ~ 89	77 ~ 95	64 ~ 90	Somewhat hard to hard (7 ~ 8)	Cannot speak in complete sentences
Near max to max	≥90	≥96	≥91	Very hard (≥9)

HRR = heart rate reserve; VO2R = oxygen uptake reserve; HRmax = maximum heart rate; VO2max = maximum oxygen uptake; RPE, rating of perceived exertion scale.