Journal List > J Nutr Health > v.50(6) > 1081530

Choi, Ju, Park, Park, and Kim: Energy expenditure of physical activity in Korean adults and assessment of accelerometer accuracy by gender∗

Abstract

Purpose

The purpose of this study was to measure energy expenditure (EE) the metabolic equivalents (METs) of 13 common physical activities by using a portable telemetry gas exchange system (K4b2) and to assess the accuracy of the accelerometer (Actigraph GT3X+) by gender in Korean adults. Methods: A total of 109 adults (54 males, 55 females) with normal BMI (body mass index) participated in this study. EE and METs of 13 selected activities were simultaneously measured by the K4b2 portable indirect calorimeter and predicted by the GT3X+ Actigraph accelerometer. The accuracy of the accelerometer was assessed by comparing the predicted with the measured EE and METs. Results: EE (kcal/kg/hr) and METs of treadmill walking (3.2 km/h, 4.8 km/h and 5.6 km/h) and running (6.4 km/h) were significantly higher in female than in male participants (p<0.05). On the other hand, the accelerometer significantly underestimated the EE and METs for all activities except descending stairs, moderate walking, and fast walking in males as well as descending stairs in females. Low intensity activities had the highest rate of accurate classifications (88.3% in males and 91.3% females), whereas vigorous intensity activities had the lowest rate of accurate classifications (43.6% in males and 27.7% in females). Across all activities, the rate of accurate classification was significantly higher in males than in females (75.2% and 58.3% respectively, p<0.01). Error between the accelerometer and K4b2 was smaller in males than in females, and EE and METs were more accurately estimated during treadmill activities than other activities in both males and females. Conclusion: The accelerometer underestimated EE and METs across various activities in Korean adults. In addition, there appears to be a gender difference in the rate of accurate accelerometer classification of activities according to intensity. Our results indicate the need to develop new accelerometer equations for this population, and gender differences should be considered.

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Fig 1.
Agreement rate of physical activity intensity classifications between K4b2 and accelerometer measurements in male and female. Activity intensity classification was described using agreement rate of physical activity intensity classification and Kappa statistics was used to describe the level of agreement rate between K4b2 and accelerometer.
jnh-50-552f1.tif
Table 1.
Description of 13 physical activities investigated
Intensity1) METs2) Activity Description
Basic   Lying Lying on bed
Light 1 ∼ 2 Sitting Sitting in an arm chair quietly
    Standing Standing without moving and speaking
    Washing dishes Washing different size dishes
    Slow walking Walking on a treadmill at 3.2 km/h
    Vacuuming Vacuuming a room (about 22m2) at a self selected speed
Moderate 3 ∼ 5 Moderate walking Walking on a treadmill at 4.8 km/h
    Descending stairs Going down the stairs from the 10th floor to the 1st floor at a self selected speed
    Fast walking Walking on a treadmill at 5.6 km/h
    Moving a box Moving a 2.5 kg box from left to right without movement of legs
Vigorous 6 ∼ Slow running Running on a treadmill at 6.4 km/h
    Ascending stairs Going up the stairs to the 10th floor at a self selected speed
    Moderate running Running on a treadmill at 8 km/h

1) Classification of physical activity intensity by Compendium 201120 2) METs: metabolic equivalents

Table 2.
Anthropometric measurements of the subjects
  Male Female Total
  (n = 54) (n = 55) (n = 109)
Age (years) 40.8 ± 12.71) 40.2 ± 12.9 40.5 ± 12.8
Height (cm) 171.0 ± 5.4∗∗ 157.8 ± 5.0 164.4 ± 8.4
Body weight (kg) 71.1 ± 9.2∗∗ 56.7 ± 8.3 63.8 ± 11.3
Body mass index (kg/m2) 24.3 ± 2.6 22.7 ± 2.9 23.5 ± 2.8
Body fat (%)2) 22.5 ± 5.7 31.6 ± 5.4∗∗ 27.1 ± 7.2

1) Mean ± SD 2) Measured by Inbody 720 Significant difference between male and female was tested by independent t-test.

p < 0.01,

∗∗ p < 0.001

Table 3.
Oxygen consumption, carbon dioxide production, energy expenditure and METs measured by K4b2
Activities 2) (L/kg/hr) VO2 VCO2 3) (L/kg/hr) Energy Ex.4) (kcal/kg/hr)   METs5)  
Male Female Male Female Male Female Total Male Female Total
Lying 0.22 ± 0.021) 0.24 ± 0.03∗ 0.19 ± 0.0.2 0.21 ± 0.03∗ 1.06 ± 0.11 1.18 ± 0.17 1.12 ± 0.156)a 1.03 ± 0.11 1.16 ± 0.16 1.10 ± 0.15a
Sitting 0.25 ± 0.03 0.26 ± 0.04 0.21 ± 0.03 0.22 ± 0.04 1.19 ± 0.17 1.25 ± 0.20 1.22 ± 0.19a 1.18 ± 0.16 1.23 ± 0.20 1.20 ± 0.18a
Standing 0.24 ± 0.06 0.25 ± 0.05 0.20 ± 0.05 0.21 ± 0.04 1.14 ± 0.27 1.20 ± 0.22 1.17 ± 0.25a 1.13 ± .26 1.18 ± 0.23 1.16 ± 0.25a
Washing dishes 0.48 ± 0.08 0.49 ± 0.09 0.38 ± 0.07 0.39 ± 0.08 2.26 ± 0.40 2.34 ± 0.45 2.30 ± 0.42b 2.26 ± 0.40 2.35 ± 0.45 2.30 ± 0.42b
Moving boxes 0.55 ± 0.12 0.58 ± 0.14 0.46 ± 0.11 0.48 ± 0.12 2.62 ± .57 2.80 ± 0.67 2.71 ± 0.63c 2.59 ± 0.56 2.78 ± 0.66 2.69 ± 0.62c
Vacuuming 0.57 ± 0.11 0.67 ± 0.16∗∗∗ 0.46 ± 0.10 0.54 ± 0.13∗∗ 2.71 ± 0.55 3.20 ± 0.75∗∗∗ 2.96 ± 0.70c 2.69 ± 0.54 3.20 ± 0.75∗∗∗ 2.95 ± 0.70c
Slow walking at 3.2 km/h 0.62 ± 0.10 0.71 ± 0.13∗∗∗ 0.51 ± 0.10 0.58 ± 0.13∗∗ 2.96 ± 0.50 3.40 ± 0.66∗∗∗ 3.18 ± 0.62a 2.93 ± 0.48 3.38 ± 0.64∗∗∗ 3.15 ± 0.61a
Descending stairs 0.68 ± 0.14 0.72 ± 0.15 0.60 ± 0.11 0.59 ± 0.11 3.31 ± 0.67 3.45 ± 0.70 3.38 ± 0.69a 3.24 ± 0.68 3.43 ± 0.73 3.34 ± 0.71a
Moderate walking at 4.8 km/h 0.81 ± 0.11 0.97 ± 0.16∗∗∗ 0.69 ± 0.10 0.81 ± 0.16∗∗∗ 3.91 ± 0.54 4.66 ± 0.79∗∗∗ 4.29 ± 0.77b 3.86 ± 0.53 4.60 ± 0.76∗∗∗ 4.23 ± 0.75b
Fast walking at 5.6 km/h 1.01 ± 0.16 1.18 ± 0.19∗∗∗ 0.88 ± 0.16 1.04 ± 0.21∗∗∗ 4.89 ± 0.79 5.75 ± 0.97∗∗∗ 5.32 ± 0.98c 4.79 ± 0.75 5.62 ± 0.91∗∗∗ 5.21 ± 0.93c
Slow running at 6.4 km/h 1.34 ± 0.21 1.50 ± 0.18∗∗∗ 1.24 ± 0.23 1.38 ± 0.21∗∗ 6.60 ± 1.06 7.36 ± 0.91∗∗∗ 6.99 ± 1.05a 6.39 ± 0.99 7.12 ± 0.85∗∗∗ 6.76 ± 0.99a
Ascending stairs 1.78 ± 0.24 1.71 ± 0.23 1.67 ± 0.20 1.74 ± 0.25 8.78 ± 1.08 8.61 ± 1.10 8.70 ± 1.09b 8.47 ± 1.12 8.15 ± 1.10 8.31 ± 1.12b
Moderate running at 8 km/h 1.73 ± 0.20 1.77 ± 0.19 1.65 ± 0.19 1.76 ± 0.20∗∗ 8.57 ± 0.97 8.86 ± 0.90 8.71 ± 0.94b 8.22 ± 0.95 8.42 ± 0.89 8.32 ± 0.92b
Total 0.78 ± 0.53 0.84 ± 0.53 0.70 ± 0.51 0.75 ± 0.54 4.15 ± 2.58 4.45 ± 2.61 4.30 ± 2.60 4.05 ± 2.47 4.34 ± 2.46 4.19 ± 2.47

1) Mean ± SD 2) VO2: oxygen consumption 3) VCO2: carbon dioxide production 4) Energy Ex.: energy expenditure 5) METs: metabolic equivalents 6) abc: Means with same superscripts are not significantly different at p < 0.05 by Tamhane's multiple comparison test (Light, Moderate activities) and Scheffe's multiple comparison test (Vigorous activites) by intensity (Light < 3METs, 3METs ≤ Moderate < 6METs, 6METs ≤ Vigorous). Significantly different between male and female by independent t-test at

p < 0.05,

∗∗ p < 0.01 and

∗∗∗ p < 0.001

Table 4.
Comparison of energy expenditure, METs and intensity for all activities measured by K4b2 and estimated by equations using Actigraph
Activities   Energy expenditure (kcal/kg/hr)     METs2)     Intensity3)  
Male Female Male Female Male Female
K4b2 Actigraph4) K4b2 Actigraph K4b2 Actigraph5) K4b2 Actigraph K4b2 A Actigraph h K4b2 A Actigraph
Lying 1.06 ± 0.111)∗∗∗ 0.00 ± 0.00 1.18 ± 0.17∗∗∗ 0.00 ± 0.00 1.03 ± 0.11∗∗∗ 1.00 ± 0.00 1.16 ± .0.16∗∗∗ 1.00 ± 0.00 L L L L
Sitting 1.19 ± 0.17∗∗∗ 0.00 ± 0.00 1.25 ± 0.20∗∗∗ 0.00 ± 0.00 1.18 ± 0.16 1.00 ± 0.00 1.23 ± 0.20∗∗∗ 1.00 ± 0.00 L L L L
Standing 1.14 ± 0.27∗∗∗ 0.00 ± 0.00 1.20 ± 0.22∗∗∗ 0.00 ± 0.00 1.13 ± 0.26∗∗ 1.00 ± 0.00 1.18 ± 0.23∗∗∗ 1.00 ± 0.00 L L L L
Washing dishes 2.26 ± 0.40∗∗∗ 0.02 ± 0.05 2.34 ± 0.45∗∗∗ 0.02 ± 0.08 2.26 ± 0.40∗∗∗ 1.00 ± 0.00 2.35 ± 0.45∗∗∗ 1.00 ± 0.02 L L L L
Moving boxes 2.62 ± 0.57∗∗∗ 0.04 ± 0.08 2.80 ± 0.67∗∗∗ 0.11 ± 0.47 2.59 ± 0.56∗∗∗ 1.00 ± 0.01 2.78 ± 0.66∗∗∗ 1.05 ± 0.32 L L L L
Vacuuming 2.71 ± 0.55∗∗∗ 0.22 ± 0.29 3.20 ± 0.75∗∗∗ 0.22 ± 0.51 2.69 ± 0.54∗∗∗ 1.06 ± 0.13 3.20 ± 0.75∗∗∗ 1.07 ± 0.35 L L M L
Slow walking at 3.2 km/h 2.96 ± 0.50∗∗∗ 1.14 ± 0.47 3.40 ± 0.66∗∗∗ 1.01 ± 0.49 2.93 ± 0.48∗∗∗ 1.28 ± 0.29 3.38 ± 0.64∗∗∗ 1.21 ± 0.30 L L M L
Descending stairs 3.31 ± 0.67 4.70 ± 1.08∗∗∗ 3.45 ± 0.70 3.60 ± 1.03 3.24 ± 0.68 4.70 ± 1.08∗∗∗ 3.43 ± 0.73 3.58 ± 1.04 M M M M
Moderate walking at 4.8 km/h 3.91 ± 0.54 3.91 ± 0.95 4.66 ± 0.79∗∗∗ 2.98 ± 1.06 3.86 ± 0.53 3.92 ± 0.94 4.60 ± 0.76∗∗∗ 2.97 ± 1.06 M M M L
Fast walking at 5.6 km/h 4.89 ± 0.79 4.90 ± 0.73 5.76 ± 0.97∗∗∗ 3.81 ± 1.15 4.79 ± 0.75 4.89 ± 0.73 5.64 ± 0.92∗∗∗ 3.77 ± 1.17 M M M M
Slow running at 6.4 km/h 6.60 ± 1.06∗∗ 5.88 ± 1.22 7.36 ± 0.91∗∗∗ 4.89 ± 1.41 6.39 ± 0.99 5.86 ± 1.21 7.12 ± 0.85∗∗∗ 4.86 ± 1.40 V M V M
Ascending stairs 8.78 ± 1.08∗∗∗ 3.97 ± 1.10 8.61 ± 1.10∗∗∗ 2.72 ± 0.79 8.47 ± 1.12∗∗∗ 3.98 ± 1.09 8.15 ± 1.10∗∗∗ 2.69 ± 0.76 V M V L
Moderate running at 8 km/h 8.57 ± 0.97∗∗∗ 7.11 ± 1.27 8.86 ± 0.90∗∗∗ 6.42 ± 1.29 8.22 ± 0.95∗∗∗ 7.08 ± 1.27 8.42 ± 0.89∗∗∗ 6.36 ± 1.29 V V V V

1) Mean ± SD 2) METs: metabolic equivalent 3) Classified by Compendium 2011 (L: Light < 3METs, 3METs ≤ M: Moderate < 6METs, 6METs ≤ V: Vigorous) 4) calculated from Freedson combination equation 5) calculated from Freedson adult (1998) Significantly different between K4b

2 and Actigraph by independent t-test at

p < 0.05,

∗∗ p < 0.01 and

∗∗∗ p < 0.001

Table 5.
Accuracy of Actigraph for energy expenditure measurement by gender
Activities Difference2) (kcal/kg/hr) Bias3) (%) RMSE4) Predictions (%)
Accurate5) Under6) Over7)
  Male Female Male Female Male Female Male Female Male Female Male Female
Lying –1.11 ± 0.16 –1.21 ± 0.20∗∗ –99.99 ± 0.10 –99.96 ± 0.16 1.12 1.23 0 0 100 100 0 0
Sitting –1.06 ± 0.17 –1.15 ± 0.22 –99.97 ± 0.21 –99.97 ± 0.15 1.07 1.17 0 0 100 100 0 0
Standing –1.14 ± 0.27 –1.20 ± 0.22 –100.00 ± 0.00 –100.00 ± 0.00 1.17 1.22 0 0 100 100 0 0
Washing dishes –2.24 ± 0.40 –2.32 ± 0.47 –98.99 ± 2.37 –98.95 ± 4.62 2.28 2.37 0 0 100 100 0 0
Moving boxes –2.59 ± 0.55 –2.69 ± 0.81 –98.78 ± 2.40 –96.26 ± 16.38 2.64 2.81 0 0 100 98.2 0 1.8
Vacuuming –2.49 ± 0.44 –2.98 ± 0.85∗∗∗ –92.75 ± 7.91 –93.23 ± 16.16 2.53 3.10 0 0 100 98.2 0 1.8
Slow walking at 3.2 km/h –1.82 ± 0.80 –2.39 ± 0.87∗∗ –59.70 ± 18.79 –68.68 ± 17.46 1.98 2.54 0 0 100 100 0 0
Descending stairs 1.39 ± 1.45∗∗∗ 0.15 ± 1.48 49.04 ± 47.70∗∗ 13.56 ± 59.90 1.99 1.47 3.7 12.7 11.1 43.6 85.2 43.6
Moderate walking at 4.8 km/h 0.00 ± 1.28 –1.68 ± 1.43∗∗∗ 2.69 ± 29.89 –33.50 ± 28.60∗∗∗ 1.27 2.20 25.9 7.3 29.6 83.6 44.4 9.1
Fast walking at 5.6 km/h 0.01 ± 1.17 –1.95 ± 1.57∗∗∗ 2.79 ± 22.29 –31.80 ± 24.66∗∗∗ 1.16 4.93 29.6 13.0 31.5 81.5 38.9 5.6
Slow running at 6.4 km/h –0.72 ± 1.46 –2.47 ± 1.61∗∗∗ –9.18 ± 20.22 –32.71 ± 20.56∗∗∗ 1.62 2.94 40.4 13.0 42.3 85.2 17.3 1.9
Ascending stairs –4.82 ± 1.58 –5.89 ± 1.27∗∗∗ –54.11 ± 13.72 –68.00 ± 9.52∗∗∗ 5.06 6.02 0 0 100 100 0 0
Moderate running at 8 km/h –1.46 ± 1.55 –2.44 ± 1.62∗∗ –16.14 ± 16.60 –26.74 ± 16.85∗∗ 2.12 2.92 32.0 17.4 62.0 82.6 6.0 0
Across all activities –1.39 ± 1.781) –2.17 ± 1.74∗∗∗ –52.07 ± 53.67 –64.89 ± 42.99∗∗∗ 2.25 2.78 10.0 4.7 75.2 90.3 14.9 5.0
Treadmill activities –0.79 ± 1.47 –2.18 ± 1.46∗∗∗ –15.96 ± 32.05 –39.03 ± 26.85∗∗∗ 1.66 2.62 25.4 9.9 53.0 86.7 21.6 3.4

1) Mean ± SD 2) Difference = predicted by Actigraph – measured by K4b

3) Bias: mean percentage error between Actigraph and K4b

4) RMSE: root mean squared error 5) The percentage of subjects predicted by Actigraph within 10% of EE measured by K4b

6) The percentage of subjects predicted by Actigraph < 10% of EE measured by K4b

7) The percentage of subjects predicted by Actigraph > 10% of EE measured by K4b2 Significantly different between K4b2 and Actigraph by independent t-test at

p < 0.05,

∗∗ p < 0.01 and

∗∗∗ p < 0.001

Table 6.
Accuracy of Actigraph for METs by gender
Activities Difference2) (METs) Bias3) (%) RMSE4)     Predictions (%)    
Accurate5) Under6) Over7)
Male Female Male Female Male Female Male Female Male Female Male Female
Lying –0.08 ± 0.162) –0.19 ± 0.20∗∗ –5.99 ± 12.72 –13.83 ± 13.93∗∗ 0.18 0.27 51.9 34.5 37.0 60.0 11.1 5.5
Sitting –0.05 ± 0.17 –0.14 ± 0.22 –2.18 ± 15.43 –8.95 ± 17.18 0.17 0.26 38.9 34.5 38.9 50.9 22.2 14.5
Standing –0.13 ± 0.26 –0.18 ± 0.23 –8.04 ± 16.03 –12.53 ± 16.41 0.29 0.29 51.9 30.9 35.2 60.0 13.0 9.1
Washing dishes –1.26 ± 0.40 –1.34 ± 0.45 –54.46 ± 7.60 –55.44 ± 9.86 1.32 1.41 0 0 100 100 0 0
Moving boxes –1.59 ± 0.55 –1.73 ± 0.72 –59.81 ± 7.71 –60.29 ± 13.77 1.68 1.87 0 0 100 98.2 0 1.8
Vacuuming –1.63 ± 0.49 –2.14 ± 0.82∗∗∗ –59.44 ± 7.15 –64.95 ± 13.29∗∗ 1.70 2.29 0 1.8 100 98.2 0 0
Slow walking at 3.2 km/h –1.65 ± 0.64 –2.17 ± 0.75∗∗∗ –54.87 ± 13.87 –62.61 ± 12.85∗∗ 1.76 2.29 0 0 100 100 0 0
Descending stairs 1.46 ± 1.46∗∗∗ 0.14 ± 1.52 52.95 ± 49.77∗∗ 13.95 ± 61.27 2.05 1.52 1.9 10.9 11.1 43.6 87.0 45.5
Moderate walking at 4.8 km/h 0.06 ± 1.26 –1.64 ± 1.40∗∗∗ 4.29 ± 30.01 –33.07 ± 28.76∗∗∗ 1.25 2.15 20.4 9.1 29.6 81.8 50.0 9.1
Fast walking at 5.6 km/h 0.11 ± 1.14 –1.87 ± 1.57∗∗∗ 4.82 ± 22.37 –31.09 ± 25.30∗∗∗ 1.13 2.43 31.5 11.1 29.6 83.3 38.9 5.6
Slow running at 6.4 km/h –0.53 ± 1.42 –2.26 ± 1.60∗∗∗ –6.55 ± 20.53 –30.92 ± 21.20∗∗∗ 1.50 2.76 42.3 16.7 36.5 81.5 21.2 1.9
Ascending stairs –4.49 ± 1.59 –5.46 ± 1.27∗∗ –52.18 ± 14.37 –66.48 ± 9.95∗∗∗ 4.76 5.60 1.9 0 98.1 100 0 0
Moderate running at 8 km/h –1.14 ± 1.54 –2.06 ± 1.61∗∗ –12.90 ± 17.31 –23.59 ± 17.76∗∗ 1.90 2.61 30.0 19.6 56.0 76.1 14.0 4.3
Across all activities –0.84 ± 1.701) –1.61 ± 1.77∗∗∗ –19.47 ± 39.08 –34.71 ± 34.42∗∗∗ 1.89 2.40 20.8 12.9 59.3 79.5 19.9 7.5
Treadmill activities –0.62 ± 1.40 –2.00 ± 1.43∗∗∗ –13.09 ± 30.88 –36.63 ± 25.75∗∗∗ 1.53 2.45 24.6 11.0 50.4 84.8 25.0 4.2

1) Mean ± SD

2) Difference = predicted by Actigraph – measured by K4b

3 Bias: mean percentage error between Actigraph and K4b

4 RMSE: root mean squared error

5 The percentage of subjects predicted by Actigraph within 10% of EE measured by K4b

6 The percentage of subjects predicted by Actigraph < 10% of EE measured by K4b

7 The percentage of subjects predicted by Actigraph > 10% of EE measured by K4b2 Significantly different between K4b2 and Actigraph by independent t-test at

p < 0.05,

∗∗ p < 0.01 and

∗∗∗ p < 0.001

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