In-Class Metabolic Calculations

In-Class Metabolic Calculations

Show every computation used to answer the questions and label every answer with the appropriate units and net or gross as required.

1. Roger (190 pounds) pedals a Monarch bicycle at 70 rev/min and 2 kg of resistance for 45 minutes, what is his VO2 in ml/kgmin, METs, ml/min, L/min?

A)190lbs/ 2.2 = 86.36 kg

B)VO2 = 1.8 (WR/BM) + 3.5 + 3.5

C)WR = 2kg * 70 rev/min * 6m = 840 kgm/min

D)VO2 = 1.8 (840/86.36) + 7

E)VO2 = 24.51 ml/kg/min divided by 3.5= 7 Mets

F)VO2 = 24.5 ml/kg/min * 86.36kg = 2115.82 ml

G)VO2 = 2115.82ml/1000 = 2.12 L/min

2. Jennifer (110 pounds) runs at a 7.5 min/mile pace for 30 minutes, 3 days/week. How long would it take her to lose 3 pounds if she does not change her diet but just begins exercising again? (hint for weight loss, use net values)

A)110lbs/2.2 = 50kg

B)60 min/hr / 7.5 min/mile = 8mph * 26.8 = 214.4 m/min

C)VO2 = (0.2*S) + (0.9*S*G) + 3.5

D)VO2= (0.2 * 214.4 m/min) + (0.9 *214.4*0) +3.5

E)VO2= (0.2*214.4 m/min)+3.5

F)Gross VO2 = 46.38 ml/kg/min

G)Net VO2= 46.38 ml/kg/min -3.5 = 42.88 ml/kg/min

H)42.88 ml/kg/min / 3.5 = 12.25 Mets

I)12.25 Mets * 3.5 *50 kg/200= 10.72 kcal/min

J)10.72 kcal/min * 30 min = 321.6 kcal/session * 3 days a week = 964.8 kcal/week.

K)3 lbs * 3500 kcal = 10500 kcals for 3 lbs of fat

L)10500 total Kcals/ 964.8 kcal/week = 10.88 weeks to loose 3 lbs of fat

3. Delbert (159 pounds) steps up and down an 8 inch bench for 20 minutes, 3 days/week. What is gross and net caloric expenditure for the workout? If Delbert’s VO2max is 45 ml/kgmin, at what percentage of VO2max is he working? He is stepping to a metronome set at 108 bpm.

A)159 lbs/ 2.2 = 72.27kg

B)8 inches * .0254 = .20 Meter bench height

C)108 bpm/4 = 27 (remember 4 steps is = to 1 count)

D)VO2 = (0.2 * F) + (1.33 * 1.8 * H * F) + 3.5

E)VO2 = (0.2 * 27) + (1.33 * 1.8 * .20 * 27) + 3.5

F)VO2 = 21.8 ml/kg/min at the given intensity

G)21.8 ml/kg/min / 45 ml/kg/min (Subjects Max VO2) = 48.5%

H)21.8 ml/kg/min – 3.5 = 18.3 ml/kg/min (Net VO2)

I)21.8 ml/kg/min / 3.5 = 6.23 Mets

J)6.23 Mets * 3.5 * 72.27 /200= 7.89 kcal/min * 20 Min = 157.8 kcal/session

K)18.3 ml/kg/min / 3.5 = 5.23 Mets

L)5.23 Mets*3.5* 72.27 /200 = 6.62 kcal/min * 20 min= 132.4 kcal per/session

4. Rose (135 pounds) was walking on the treadmill at 3.7 mi/hr, 5% grade. However, due to shin splints, she must switch to the Tunturi bicycle ergometer. If she can pedal at 75 rev/min, what resistance should she use to work at an equivalent VO2? Does this seem reasonable?

A) 135 lbs/2.2 = 61.36 kgs

B) 3.7 mph x 26.8 = 99.16 m/min

C) VO2 walking = (0.1* 99.16) + (1.8*99.16*.05) + 3.5

= 9.92 + 8.92 + 3.5

= 22.34 ml/kg/min

D) VO2 biking= (1.8 * WR/BM) + 3.5 + 3.5 WR = R*75 rev/min*3 m/rev = 225R

22.34= (1.8 * 225R/61.36) + 7

22.34= (6.60R) + 7

15.34= 6.60R

E) Answer: R= 2.32 kg Yes it is reasonable.

5. Howard (180 pounds) uses the Monarch (2.4m/rev) arm ergometer with setting of 1 kg and 50 rpm. He exercises for 40 minutes, 5 days/week. How long will it take him to lose 10 pounds? If he also reduces his caloric intake by 200 kcal/day in addition, how long will it take for him to lose the weight?.

A) 180 lbs./2.2 = 81.82 kg

B) Work Rate (WR) = 1 kg * 50 rev/min * 2.4 m/rev = 120 kgm/min

C) VO2 arm cycling= 3* WR/BM + 3.5

= 3 * 120/81.82 + 3.5

= 4.40 + 3.5

= 7.90 ml/kg/min (gross)

= 7.90 – 3.5 = 4.41 ml/kg/min (net)

0 200

E) 40 mins * 1.8 kcals/min * 5 days/week = 360 kcals/week

F) 10 pounds x 3,500 kcals = 35,000 kcals/360 kcals/week = 97.22 weeks to lose 10 pounds with exercise only.

G) 200 kcals/day x 7 days/week = 1400 kcals/week + 360 kcals/week = 1760 kcals/week

H) 35,000/1,760 kcals/week = 19.89 weeks to lose 10 pounds with diet and exercise.

6. Fred (166 pounds) used to run on the treadmill at 8 mph. Fred has a stress fracture now (overtraining?). Therefore he is going to switch to walking but can walk at a maximum pace of 4.0 mph. What would the grade have to be for Fred to get a comparable intensity walking?

Does this grade seem reasonable?

A) 166 lbs./2.2 = 75.45 kgs

B) 8 mph * 26.8 = 214.40 m/min

C) 4 mph * 26.8 = 107.20 m/min

D) VO2 running = (0.2 * S) + (0.9 * S * G) + 3.5

= (0.2 * 214.40) + (0.9 * 214.40 * 0) + 3.5

= (42.88) + (0) + 3.5

= 46.38 ml/kg/min

E) VO2walking 46.38 = (0.1 * 107.20) + (1.8 * 107.20 * G) + 3.5

46.38 = 10.72 + 192.96G + 3.5

32.16 = 192.96G

G = 16.67% or 17%

F) Realistic?: I’d say no, not with a stress fracture.