How imperfect is the human machine

  • Thread starter Thread starter bobie
  • Start date Start date
  • Tags Tags
    Human Machine
Click For Summary

Discussion Overview

The discussion revolves around the efficiency of human muscle performance, particularly in relation to energy expenditure during physical activity. Participants explore concepts of energy burned versus work done, and the implications of muscle efficiency on overall energy use.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant inquires about the relationship between energy spent (10 joules) and calories burned, suggesting a rough estimate of 120% energy expenditure.
  • Another participant states that for every Joule of work, approximately 4 to 5 Joules are burned, referencing muscle efficiency.
  • A later reply mentions that skeletal muscles require energy to maintain force even without performing work, indicating additional energy expenditure.
  • One participant cites a source suggesting that the human body operates at roughly 20% efficiency, arguing that this is a reasonable performance given the second law of thermodynamics.

Areas of Agreement / Disagreement

Participants express varying views on muscle efficiency and energy expenditure, with no consensus reached on specific values or interpretations of efficiency.

Contextual Notes

Participants acknowledge that energy expenditure can vary among individuals and is influenced by multiple factors, but specific assumptions and definitions are not fully explored.

bobie
Gold Member
Messages
720
Reaction score
2
If we pull/ push a weight of 10kg and dislocate it 1 meter the energy spent is 10 joules, can someone tell me roughly if 10 j is 100% can anyone tell me how much energy (calories) has been burned /wasted in excess? I suppose it can vary in different persons and by different factors, I'd like to get just a rough idea, 120%?
 
Biology news on Phys.org
For every Joule of work, you burn 4 to 5 Joules. Google muscle efficiency for more details.
 
Thanks, very helpful
 
  • Like
Likes   Reactions: 1 person
According to a book I'm reading, the human body is running roughly at 20% efficiency. Seeing that nothing can be at 100% efficiency (2nd law of thermodynamics) I'd say the human body is doing perfectly well.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
10
Views
5K
  • · Replies 15 ·
Replies
15
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
Replies
2
Views
2K