wphamilton

Some cooling comes from respiration and blood circulation (transferring heat to the surface), but it would be surprising if that represented a significant amount of calories. Primarily our cooling comes from perspiration (agreed?) but the sweating itself burns a small amount of calories. Therefore I'm skeptical, the article you quote later notwithstanding.

surgeonstone

Actually pigs do sweat and have skin that is very similar to a humans. However the number of sweat glands, being much lower than a human, contribute little to thermoregulation hence their need to wallow in mud.

kenji666

Sweat is just the body's process of shedding heat by evaporative cooling. It does not require any extra calories to produce sweat than it does to produce urine.

Campag4life

Good discussion. My take away reading both pros and cons of what is written is...body core temp likely doesn't change much aka if it did, it would probably do much harm. Of course delta T aka internal body temp relative to external temp can be dramatically different. When delta T is big, sweat results in an effort cool the body to maintain core temp. Perspiration itself doesn't result in additional caloric burn...or very modest if any affect.

So likely as stated, increased calorie burn in higher temp weather must be due to other factors. Not sure if mean heart rate goes up in the summer as I don't train with a monitor. I believe my diet is similar but perhaps not. I though perhaps the process of hydration had a flushing effect of fat in the body but most seem to think this is bogus or not material.

In any event, I am glad I am dropping weight. I am riding stronger as well. I suppose there could be a synergistic effect in play. Because I am becoming fitter coming off sedendary winter months, maybe my metabolism has sped up and I am naturally burning more calories. So I am changing based upon my riding regiment which is changing my metabolism. Which leads me full circle to....I need to move out of the Midwest and get in a climate I can ride more months out of the year. That way I can be more fit year around.
Thanks everybody.

RUOkie

I've seen a lot of really dumb threads on BF, but this makes the top 10. The amount of "internet knowledge" (otherwise known as sheer ignorance) being posted here is astounding.

Machka 

Body core temp doesn't change much ... it shouldn't go over 40C (104F) which is a pretty high fever and can result in some serious damage, and it shouldn't drop lower than 35C (95F) which is when hypothermia starts. So there's a 5C range a person can be in without going into dangerous territory, and only about a 1C range of that is comfortable.

RT

Amen.

WhyFi

Does this mean that I should ditch my Saran Wrap base layer?

Campag4life

Creating such a thread is worth it for the pure entertainment of watching posters like yourself come forward...and embarrass themselves...which of course is a false premise because you aren't smart enough to have any shame. Instead of setting the record straight with your prevailing wisdom, you do the only thing you are good at. Troll.

pallen

No, just drop all layers on top of that. You're still in MN, right? I don't think I'll see you anywhere I ride

Campag4life

Sounds right. But because calories by definition relates to heat and temp, lets say core temp raises by 1 deg C during an intense workout in high ambient heat. This 'could' affect caloric burn rate. Only a hypothesis.

Machka 

A suggestion ... take your temperature.

You can get a thermometer quite inexpensively at most pharmacies ... so take your temperature when you wake up in the morning, before you do anything active and before your shower. Take your temperature just before you head out on your ride. Then take your temperature during your ride, after you get all warmed up and start sweating.


So far, you're just using perception as your guideline, but you can track some real data.

-- body temperature (with your thermometer)
-- heart rate ... get your resting HR, your pre-ride HR, and your HR throughout the ride
-- distances you ride each day that you ride throughout a year. Use some method to record your rides over a year.
-- ride time ... how long did it take you to do each ride? total time? on-bike time?
-- calories consumed ... meticulously track your calories consumed for 3 weeks in the heat of summer, and again for 3 weeks in the chill of winter.

DaveWC

Seriously? Given that even a cursory attempt at googling the premise that sweating increases calorie burn yields absolutely no evidence supporting your claim I'd say the embarrassment doesn't lie with those that mock the concept of this thread. Surely you could have "set the record straight" on your own in seconds.

RT

C4L, chill buddy. It is a worthy topic, but the amount of drilling down to get to the minute details about a simple bodily function is pure 41. We ride our bikes. We get hot. We sweat. This does not always mean weight loss unless the thread devolves into an argument about scientific principle, which is what has happened. That was the only point.

Campag4life

Fair point.

Campag4life

But RT, I don't see argument default to scientific principle as devolving. I view this as evolving to the truth. Many have come forward and dismissed the notion that sweating has anything to do with weight loss...over and above obvious dehydration. I am evolving on the subject as well.

kenji666

That must be pretty uncomfortable riding with that thermometer up your...

Campag4life

Here is the problem Macka with introducing scientific metrics. You don't know the respective weighting of the parameters you proposed in terms of relative contribution to weight loss. If you do, please post percentages of each contribution. Therefore data acquisition will be not only tedious but irrelevant. You could perform a scientific study I suppose using regression or Tagucci methods over a varied sample size of riders to try to correlate respective contribution but this would be an involved study and worthy of a PHD dissertation. I believe all of us would be further ahead if you would just post this study if you know the relative weighting of this data in terms of calories burned. My guess is, it doesn't exist.
Thanks.

Machka 

You might still do it that way, but I think most people use thermometers under their armpits, in their ears, or under their tongues ... depending on the thermometer you get.

Note that the "normal" temperature acquired by each of those methods is slightly different, but if you use a particular method consistently, you'll get decent data.

Machka 

I'm talking about YOU.

You perceive that you're losing weight in the summer. Why?

If you track the amount you eat in summer vs. winter, you might discover that you eat fewer calories in the summer vs. winter.

If you track the amount of cycling you do all year long, you might discover that you cycle more in the summer than in the winter.

If you make those discoveries, that would explain why you're losing weight in the summer.


You perceive you're working harder in the winter than you are in the summer. So track your HR for a few weeks in the winter and a few weeks in the summer, and see if your perception is indeed true.


You proposed a theory that your body core temperature might go up during an intense workout in hot temperatures ... so take your temperature and see if that actually happens.


It's not that complicated.

RJM

I spent some time in New Orleans drinking, boozing, hanging...sweating my ass off because it was so hot. I didn't lose one pound, in fact I gained some. I think the Op's metric is a little off.

Campag4life

Point taken. My weight loss maybe related to other things as you say. Hard to precisely track everything but unless you do, then difficult to say what the contributors are. I really wasn't trying to identify some of the well known contributors...understood that diet is biggest factor...and how much you ride and intensity of how you ride. Seems like my biggest weight loss periods are dead of summer when I sweat the most is the simple premise of thread. Now understood that many dismiss this notion.

Machka 

You probably do lose the most weight during the summer ... when you ride more, when you eat more fruit and veg, when you burn more than you consume, etc., etc.


But not because you're losing a bit of water and electrolytes in sweat.

Campag4life

I have learned something then. I thought there maybe a correlation. Another poster mentioned HR. I know my fitness has improved. I am riding faster and able to sustain higher intensity. That is for certain. So perhaps if my diet is the same and I am logging more miles, I am riding those miles harder but it doesn't seem harder because I am more fit...but I maybe burning more calories. I know my average speed is up. Oh oh...I mentioned average speed on the 41.

kenji666

Quick, someone close this thread before someone mentions Lance... uh-oh, too late.