Table 1.

Differences in definitions and threshold for intensity from different exercise organizations over the past 20 years

	ACSM v6 (2000)			Exercise and Sports Science Australia (2010)			ACSM v10 (2018)
Definitions	%HRR	%HRmax	RPE	%HRR	%HRmax	RPE	%HRR	%HRmax	RPE
Very light/sedentary	<20	<35	<10	<20	<40	<8	<30	<57	<9
Light	20–39	35–54	10–11	20–39	40–55	8–10	30–39	57–63	9–11
Moderate	40–59	55–69	12–13	40–59	55–70	11–13	40–59	64–76	12–13
Hard/vigorous	60–84	70–89	14–16	60–84	70–90	14–16	60–84	77–95	14–17
Very hard to maximal	85–100	90–100	17–20	85–100	90–100	17–20	85–100	96–100	18–20

Abbreviations: ACSM, American College of Sports Medicine; HRR, heart rate reserve.