Why do you feel hot after lifting weights?

[Roxy]

Can someone help me. The questions are in bold and my anwsers are not. Can someone explain it to me.

1. Why do you feel hot after lifting weight?
Does it have something to do with cellular respiration..
2. Can you tell when your muscles went into anaerobic respiration? What evidence was there?
pain?
3. How many more times powerful were you during aerobic exercise than during anaerobic exercise?
?

 

[Astronuc]

Excercising, or in general, using muscles requires chemical energy, which produces heat.

Buildup of lactic acid which causes pain -

The expression "lactic acid" is used most commonly by athletes to describe the intense pain felt during exhaustive exercise, especially in events like the 400 metres and 800 metres. When energy is required to perform exercise it is supplied from the breakdown of Adenosine Triphosphate (ATP). The body has a limited store of about 85 grms of ATP and would use it up very quickly if we did not have ways of resynthesising it. There are three systems that produce energy to resynthesise ATP: ATP-PC, lactic acid and aerobic.

from Lactic acid

3. How many more times powerful were you during aerobic exercise than during anaerobic exercise?

Not sure about what is being asked.

Anaerobic metabolism/respiration kicks in when the body performs an activity during which the circulatory system (including cardio-pulmonary system) cannot delivery oxygen to the muscles fast enough. The oxygen deficiency then causes anaerobic respiration.

One can for instance lift heavy weight slowly, or a lighter weight with rapid repetitions. In the latter, one is likely to initiate anaerobic respiration.

Interesting discussion on muscle development - http://home.hia.no/~stephens/hypplas.htm Has the debate been settled?