Factors And Models Of Activity Energy Expenditure Of Health Adults During Level Walking

Objective The study is aimed to measure Resting Energy Expenditure (REE) and Activity Energy Expenditure(AEE) of health adults during level walking, and to analyze the characteristics and influencing factors such as age and gender. Meanwhile, we build the mathematical models of velocity and AEE, velocity and METs, cadence and AEE, cadence and METs of health adults in different age and gender. Methods Total 60 health adults, including 30 males and 30 females, participate in the study, all of them aged 20-50 years. They are divided into six groups by gender and age (10 years). Volunteers walk at 3.5,4.5,5.5km/h and run at 5.5,6.5,7.5km/h on the treadmill. REE and AEE are collected by indirect calorimetry, cadence is recorded by artificiality, including walking and running. At each interval, there is a 5-minute rest.Results 1. REE of 41-50 years old females is lower than 21-30 years old females and males (P<0.05).2. There is no difference of AEE between female and male at the same age (P>0.05). At 3.5km/h walking, AEE of 21-30 years old females is lower than 31-40 years old females and males (P<0.05); At 4.5km/h walking, AEE of 31-40 years old females is higher than 21-30 years old females and males and 41-50 years old females;AEE of 21-30 years old females is lower than 41-50 years old males (P<0.05); At 5.5km/h walking, AEE of 31-40 years old females is higher than 21-30 years old females and males (P<0.05); At 6.5km/h running, AEE of 31-40 years old females is higher than 41-50 years old females (P<0.05); At 7.5km/h running, AEE of 21-30 years old males is higher than 41-50 years old females (P<0.05). At 5.5km/h walk-run transition speed, all groups except 41-50 years old females perform that AEE in running is higher than walking (P<0.05).3. At 3.5km/h walking, METs of 21-30 years old females is lower than 31-40 years old females and males and 41-50 years old females (P<0.05); At 4.5km/h walking, METs of 31-40 years old females is higher than 21-30 years old females and males; At 5.5km/h walking, AEE of 31-40 years old females is higher than 21-30 years old females and males (P<0.05); There is no difference of METs between each group at 6.5km/h and 7.5km/h.4. Velocity and AEE have liner correlation, and R~2 is 0.92-0.98, velocity and METs have same correlation, and R~2 is 0.92-0.98; the cadence has the same relationship with AEE, and R~2 is 0.62-0.78; the cadence has the same relationship with METs, and R~2 is 0.54-0.68.Conclusions Age has more effect on REE and AEE than the gender. AEE of old people is higher than the young during walking, however, AEE of young people increases faster than other people during running. AEE of 31-40 years old females is highest in all groups both in walking and running. At walk-run transition speed, AEE in running is higher than in walking. Results of METs of each group is similar as AEE during walking, but METs is no difference between each group when running. AEE can be calculated by cadence and velocity, and METs also could be predicted by these.