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