Question

Scenario 2: Use the following information to answer questions 3 and 4:

Your client, Jim, is interested in weight control. He weighs 75kg.
3. If Jim walks 3.3 mph (0% grade), how long must he walk to expend 300 kcal total?
A. 52 min
B. 42 min
C. 65 min
D. 99 min
4. If Jim exercises at an intensity of 6 kcal/min, what is the leg ergometer work rate?
A. 47 watts
B. 90 watts
C. 61 watts
D. 71 watts

Answer 1

To expend 300 kcal walking at 3.3 mph, Jim would need to walk for approximately 52 minutes. The leg ergometer work rate for Jim exercising at an intensity of 6 kcal/min is approximately 71 watts.

Step-by-step explanation:

To calculate how long Jim must walk to expend 300 kcal, we can first determine the amount of time it takes for him to burn 1 kcal. Since Jim weighs 75 kg and exercises at an intensity of 6 kcal/min, it would take him 1/6 minute to burn 1 kcal. Therefore, to burn 300 kcal, Jim would need to walk for 1/6 * 300 = 50 minutes, which is closest to option A: 52 minutes.

To find the leg ergometer work rate, we can use the formula Power = work/time. Since Jim exercises at an intensity of 6 kcal/min, which is equivalent to 6 * 4.18 J/min, and work = Power * time, we can solve for work using the values given. If we substitute work = 6 * 4.18 J/min and time = 1 min, we can solve for Power, which is equal to 6 kcal/min. Therefore, the leg ergometer work rate would be equal to 6 * 4.18 J/min = 24.18 J/min, which is closest to option D: 71 watts.

Answer 2

A. 52 min

.A. 47 watts

Step-by-step explanation:

Given that;

jim weighs 75 kg

and he walks 3.3 mph; the objective here is to determine how long must he walk to expend 300 kcal.

Using the following relation to determine the amount of calories burned per minute while walking; we have:

`(MET*weight (kg)*3.5)/(200)`

here;

MET = energy cost of a physical activity for a period of time

Obtaining the data for walking with a speed of 3.3 mph From the standard chart for MET, At 3.3 mph; we have our desired value to be 4.3

However;

the calories burned in a minute =
`(4.3*75 (kg)*3.5)/(200)`

= 5.644

Therefore, for walking for 52 mins; Jim burns approximately 293.475 kcal which is nearest to 300 kcal.

4.

Given that:

mass m = 75 kg

intensity = 6 kcal/min

The eg ergometer work rate = ??

Applying the formula:

`V_O_2 ( intensity ) = ( (W)/(m)*1.8)+7`

where ;

`V_O_2 ( intensity ) = (1 \ kcal min^(-1)*10^(-3))/(5)`

`V_O_2 ( intensity ) = (6*1 \ kcal min^(-1)*10^(-3))/(5)`

`V_O_2 ( intensity ) = 0.0012`

∴
`0.0012 = ((W)/(75)*1.8)+7 \\ \\ W = (0.0012-7)/(1.8)*75 \\ \\ W = (7*75)/(1.8) \\ \\ W = 291.66 \ kg m /min`

Converting to watts;

Since; 6.118kg-m/min is = 1 watt

Then 291.66 kgm /min will be equal to 47.67 watts

≅ 47 watts