Participants
Twenty two participants took part in the study, and they have ages mean 29.27 standard deviation (S.D.) 6.97 ranged 2149 years old, heights mean 168.45 SD 10.14 ranged 155191 cm, weights mean 71.69 SD 10.12 ranged 51120 kg, body mass index (BMI) mean 25.01 SD 4.92 ranged 20.440.7, and 10 male and 12 female.
Variables given by Oxycon Mobile ® system
The results on the major parameters, e.g. VO2 are shown in Table 1, and each parameter is analysed and plotted, one by one, as below.
VO2 mean ml/min
The level of oxygen consumption (VO2 mean, ml/min) in the S1, S2, S3 showed strong correlation with T1, T2, T3, where S1 and T1 are baseline cadence in stepper and treadmill movements, S2 and T2 represents 20% higher cadence than the baseline one, and S3 and T3 20% lower cadence than the baseline one. Mean values showed that S3 consumed more energy than T3 by approximately 14% (Table 1). The correlation coefficient between stepper and treadmill movements in VO2 is very strong (0.789, p< 0.001) and a linear regression was constructed as seen in Figure 4.
Table 1. VO2 oxygen consumption and other parameters using stepper and treadmill
Measure

Mean

Std. Error

95% Confidence Interval

p

note

Lower Bound

Upper Bound

VO2 Mean ml/min

R

255.6

18.3

217.4

293.9

<0.001

vs all

S1

834.5

63.9

700.7

968.3

0.285

vs T1

S2

919.5

71.4

770.1

1068.9

0.478

vs T2

S3

772.2

63.7

638.8

905.6

<0.016

vs T3

T1

796.8

62.6

665.8

927.8

T2

959.6

73.7

805.3

1113.9

T3

677.7

58.4

555.6

799.9

EqO2 Mean

R

33.6

1.1

31.2

35.9

<0.001

vs all

S1

29

0.7

27.6

30.4

0.455

vs T1

S2

29

0.7

27.5

30.5

0.56

vs T2

S3

28.2

0.6

26.9

29.4

<0.001

vs T3

T1

28.3

0.8

26.6

30.1

T2

28.6

0.7

27.1

30.1

T3

29.9

0.5

28.8

31

VCO2 Mean ml/min

R

234

16.9

198.5

269.4

<0.001

vs all

S1

799.9

69.8

653.8

945.9

<0.008

vs T1

S2

859.8

71.8

709.6

1010.1

0.905

vs T2

S3

670.8

54.1

557.6

784

<0.031

vs T3

T1

690.8

52.6

580.7

800.9

T2

853

63.7

719.8

986.2

T3

598.8

55.3

483

714.7

VO2 Max ml/min/kg

R

4.44

0.3

3.81

5.07

p<0.001

vs all

S1

12.35

0.66

10.97

13.73

0.291

vs T1

S2

13.79

0.72

12.29

15.28

0.751

vs T2

S3

11.37

0.57

10.17

12.56

0.003

vs T3

T1

11.75

0.54

10.63

12.87

T2

14.03

0.78

12.39

15.66

T3

10.03

0.47

9.03

11.02

EqCO2 Mean

R

36.5

1.1

34.2

38.8

<0.001

vs all

S1

30.6

0.6

29.3

31.8

<0.022

vs T1

S2

31.3

0.7

29.7

32.8

0.3

vs T2

S3

32.5

0.7

30.9

34

<0.001

vs T3

T1

32.5

0.8

30.8

34.2

T2

32.1

0.8

30.3

33.9

T3

34.1

0.8

32.4

35.7

Note: R rest, S1–stepper movement with a normal cadence, S2stepper cadence 20% higher than normal one, S3 stepper cadence 20% lower than the normal, T1treadmill walking with a normal cadence, T2treadmill 20% higher, T3treadmill 20% lower
Breathing equivalent for oxygen (EqO2)
EqO2 mean in S1 (28.992) was very close to T1 mean value (28.33). It was found that the difference between S3 and T3 was significant, and T3 was higher than S3 by approximately 6% (Table 1). The correlation coefficient was also strong (0.489, p <0.001) and linear regression as seen in Figure 5. The mean at Rest was observed at 33.560, which was significantly higher than the other situations, because EqO2 is reversely proportional to VO2.
Volume of CO2 expired
VCO2, which is the production of carbon dioxide per minute, was recorded. It is found that S1 and S3 were higher than T1 and T3 by approximately 16% and 11% respectively (Table 1). The correlation coefficient between two types of movements is 0.778 (p<0.001) as seen in Figure 6.
Respiratory exchange ratio (RER)
RER mean values showed a correlation between stepper and treadmill as in Figure 8, and S1 and S2 higher than T1 and T2 by approximately 8% and 6% respectively (Table 2). The correlation coefficient is 0.507 with p< 0.001, again confirming the correlation between the stepper and treadmill movements.
Table 2 Respiratory exchange ratio and parameters in stepper and treadmill measurements
Measure

Mean

Std. Error

95% Confidence Interval

p

note

Lower Bound

Upper Bound

Qtc Mean L/min

R

1.9

0.1

1.6

2.1

<0.001

vs all

S1

5.5

0.4

4.6

6.4

0.323

vs T1

S2

6.1

0.5

5.1

7.1

0.682

vs T2

S3

5

0.4

4.2

5.9

<0.033

vs T3

T1

5.3

0.4

4.4

6.1

T2

6.3

0.5

5.3

7.2

T3

4.5

0.4

3.8

5.3

MET Mean

R

1

0.1

0.9

1.1

<0.001

vs all

S1

3.2

0.2

2.8

3.6

0.221

vs T1

S2

3.5

0.2

3.2

3.9

0.513

vs T2

S3

3

0.2

2.7

3.3

<0.002

vs T3

T1

3

0.1

2.7

3.3

T2

3.7

0.2

3.2

4.2

T3

2.6

0.1

2.3

2.8

VE Mean L/min

R

9.6

0.7

8.2

11.1

<0.001

vs all

S1

26.2

2.2

21.5

30.8

<0.042

vs T1

S2

28.9

2.7

23.3

34.6

0.916

vs T2

S3

23.5

1.8

19.8

27.1

0.115

vs T3

T1

24

1.7

20.4

27.6

T2

29.1

2.2

24.5

33.7

T3

21.8

1.7

18.2

25.5

EE mean Kcal/min

R

1791.7

130.1

1519.4

2064.1

<0.001

vs all

S1

5979.2

472.1

4991.1

6967.3

0.129

vs T1

S2

6557.5

518.3

5472.7

7642.3

0.597

vs T2

S3

5420

447

4484.4

6355.7

<0.018

vs T3

T1

5592

437.4

4676.5

6507.5

T2

6774.3

519.1

5687.9

7860.7

T3

4769.2

418.6

3893.1

5645.3

RER Mean

R

0.92

0.018

0.882

0.959

<0.05

vs S3/T1

S1

0.95

0.017

0.915

0.985

<0.001

vs T1

S2

0.929

0.014

0.9

0.958

<0.009

vs T2

S3

0.871

0.011

0.848

0.893

0.332

vs T3

T1

0.873

0.015

0.84

0.905

T2

0.893

0.012

0.867

0.919

T3

0.881

0.013

0.854

0.908

Note: R rest, S1–stepper movement with a normal cadence, S2stepper cadence 20% higher than normal one, S3 stepper cadence 20% lower than the normal, T1treadmill walking with a normal cadence, T2treadmill 20% higher, T3treadmill 20% lower
Energy consumption using stepper and treadmill (EE)
At Rest, the lowest mean of energy consumption (EE) was recorded as 1791.723. It was found that S3 was significantly higher than T3 by approximately 14% as shown in Table 2. The correlation coefficient was 0.790 with p<0.001 as in Figure 9, showing strong correlation between two types of movements.
Ventilation (VE)
VE mean value showed that S1 was higher than T1 by approximately 9% in Table 1. The correlation coefficient between stepper and treadmill is 0.826 with p<0.001 as Figure 10.
MET using stepper and treadmill
Mean value for MET showed that S3 is higher than T3 by approximately 15% in Table 2. The correlation coefficient for MET was 0.598 with p<0.001 as Figure 11, so two type of movements were correlated.
Qtc
Qtc results showed correlation between stepper and treadmill as well, with the coefficient as 0.806 with p<0.001 as in Figure 12. It is also found that S3 is higher than T3 by approximately 11% as in Table 2.