Table 2. Energy expenditure and macronutrient composition by heart rate zone.

	Polar Grit X Pro (Mean ± SD)	Metabolic cart (Mean ± SD)	ICC	ICC Interpretation	95% CI	F	p
Exercise intensities combined
n	75	75
Calories	122 ± 36	111 ± 32	0.80	Excellent	0.61-0.89	11.76	<0.001***
%FAT	39 ± 23	35 ± 18	0.49	Fair	0.30-0.65	2.98	<0.001***
%CHO	61 ± 23	65 ± 18	0.49	Fair	0.30-0.65	2.98	<0.001***
Zone 1 (50-59% HRmax)
n	16	16
Calories	75 ± 9	69 ± 12	0.15	Poor	-0.30-0.58	1.39	0.259
%FAT	69 ± 4	53 ± 21	0.04	Poor	-0.24-0.41	1.11	0.415
%CHO	31 ± 4	47 ± 21	0.04	Poor	-0.24-0.41	1.11	0.415
Zone 2 (60-69% HRmax)
n	16	16
Calories	103 ± 16	96 ± 18	0.58	Fair	0.16-0.83	4.33	0.005**
%FAT	54 ± 8	35 ± 17	0.14	Poor	-0.12-0.49	1.79	0.185
%CHO	46 ± 8	65 ± 17	0.14	Poor	-0.12-0.49	1.79	0.185
Zone 3 (70-79% HRmax)
n	16	16
Calories	129 ± 19	120 ± 15	0.26	Poor	-0.19-0.65	1.79	0.129
%FAT	36 ± 12	30 ± 13	0.15	Poor	-0.31-0.58	1.39	0.260
%CHO	64 ± 12	70 ± 13	0.15	Poor	-0.31-0.58	1.39	0.260
Zone 4 (80-89% HRmax)
n	14	14
Calories	150 ± 16	135 ± 15	0.09	Poor	-0.25-0.51	1.28	0.328
%FAT	21 ± 10	29 ± 14	0.28	Poor	-0.16-0.67	2.01	0.112
%CHO	80 ± 10	71 ± 14	0.28	Poor	-0.16-0.67	2.01	0.112
Zone 5 (90-100% HRmax)
n	13	13
Calories	166 ± 17	146 ± 17	0.07	Poor	-0.23-0.48	1.24	0.354
%FAT	7 ± 5	25 ± 13	0.09	Poor	-0.10-0.42	1.68	0.238
%CHO	93 ± 5	75 ± 13	0.09	Poor	-0.10-0.42	1.68	0.238

%CHO, present calories from carbohydrate; CI, confidence interval; %FAT, percent calories from fat; ICC, intraclass correlation coefficient; SD, standard deviation.** p < 0.01,*** p < 0.001