. Author manuscript; available in PMC: 2009 Jun 23.

Published in final edited form as: Obesity (Silver Spring). 2008 May 29;16(8):1946–1952. doi: 10.1038/oby.2008.279

Table 2.

Selected regression equations for AG, AC, and RT3 accelerometers explored in this work are shown (ct = activity count)

Equation number	Developer	Activity monitor	Regression equation(s)
AC 1	Heil (7)^a	Actical	AEE = (0.02779 + 1.143e-5 × ct) × weight (kg)
AC 2	Heil (7)^a	Actical	AEE = (0.01217 + 5.268e-5 × ct) × weight (kg) 350 < ct ≤ 1,200
			AEE = (0.02663 + 1.107e-5 × ct) × weight (kg) ct > 1,200
AG 1	Freedson et al. (9)	ActiGraph	AEE = 1.91e-5 × ct × weight (kg) ct ≤ 1,952
	Work energy (20)		AEE = 9.4e-4 × ct + 0.1346 × weight (kg) – 7.37418 ct > 1,952
AG 2	Hendelman et al. (10)	ActiGraph	METs = 2.922 + 4.09e-4 × ct
AG 3	Yngve et al. (12)	ActiGraph	METs = 1.136 + 0.0008249 × ct
RT3 1	StayHealthy	RT3	Proprietary
RT3 2	Chen and Sun (6)^b	RT3	AEE = (ct/76.2)^0.533 × (0.203 + 6.8e-3 × weight (kg))
RT3 3	Hendelman et al. (10)^b	RT3	METs = (ct × 1.21) × 0.00187 + 1.136

AC, Actical; AEE, activity energy expenditure; AG, ActiGraph; METs, metabolic equivalents.

ct ≤ 50: AEE = 0; 50 < ct ≤ 350: AEE = 0.007565 × weight (kg).

Equations modified by correction factors to convert from TriTrac to RT3 accelerometer.