1 / 19

Energy Expenditure during various Activities

Energy Expenditure during various Activities. Oxygen Uptake. Energy utilized for O 2 consumed: 5 kcal/L of O 2 If a person burns 600 calories during a run, how many liters of O 2 did he/she consume?. Energy Expenditure. Gross Energy Expenditure Net Energy Expenditure

frye
Download Presentation

Energy Expenditure during various Activities

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Energy Expenditure during various Activities

  2. Oxygen Uptake Energy utilized for O2 consumed: • 5 kcal/L of O2 • If a person burns 600 calories during a run, how many liters of O2 did he/she consume?

  3. Energy Expenditure Gross Energy Expenditure Net Energy Expenditure • expenditure due to activity • subtract resting energy expenditure

  4. Energy Expenditure A runner burns 600 calories during a 45 minute run: • 6’0” • 190 lbs. • Age: 37 • Find Net Energy Expenditure

  5. Energy Expenditure Runner • Estimate Body Surface Area (nomogram - Figure 9.4) • Estimate BMR (Figure 9.3) • Calculate Resting Energy Expenditure (kcal/hour)

  6. Energy Expenditure Net Energy Expenditure = Gross Energy Expenditure – BMR

  7. Energy Expenditure/O2 Consumption Constant load / light to moderate exercise • Assessed 1-2x during steady state Exercise w/ varying loads • Assessed multiple times

  8. Mechanical Efficiency (%) • = Mechanical work accomplished / Input of energy * 100 • Mechanical work = ergometer • Energy input = O2 consumption • Work equivalent: 1 kcal = 426 kg-m perfect)

  9. Mechanical Efficiency (%) • Human locomotion = 20-30% • Dissipated energy to internal & external friction

  10. Walking Efficiency • Sand  2x energy expenditure • Soft-soled running shoe   O2 consumption x 2.4% • 100g (3.52 oz.) to each shoe   O2 consumption x 1%

  11. Effects of Downhill Walking 14 13 12 11 10 Net Oxygen Consumption (mL/kg-min) 9 8 7 6 5 -18 -15 -13 -9 -6 -3 0 % Grade

  12. Walking vs. Running

  13. Running Economy • Energy cost not dependent on velocity • Horizontal running  net energy expenditure = 1kcal/kg-km (1km = 0.62 miles) • A 220 lb. man runs 10 km, what is the net energy expenditure?

  14. Running: Frequency vs. Stride Length Frequency Stride Frequency and Stride Length (cm) Length 90 20 30 10 Speed (km/h)

  15. Frequency Stride Frequency and Stride Length (cm) Length 10 16 Speed (km/h) Walking: Frequency vs. Stride Length 220 120

  16. Stride Length 3.9 Oxygen Uptake (L/min) 3.7 3.5 3.3 134 154 118 Stride Length (cm)

  17. Air Resistance Effect dependent on: • air density • surface area • velocity2 • 9.86 vs. 41 mph wind • 2.92 vs. 4.1 L/min (41%)

  18. Drafting • Running @ 6 m/s • 1 m behind •  energy expenditure by 7% • Cycling @ 25 mph •  energy expenditure by 26-38%

  19. Treadmill vs. Non-Tmill Running • No differences aerobically (submax and max)

More Related