Glycogen depletion

[BecomeLegendary]

One question I have had for a very long time is how much faster do glycogen levels plummit when doing LISS outside vs on a treadmill. I did LISS for 40 mins outside yesterday in 90 degree heat with very high humidity. Sure I sweat a ton, but does anyone know if there is some sort of coefficient for how many more calories are burned outside compared to nice and easy treadmill running?

[caa5000]

the lower the intensity, the less glycogen that is used. Chances are you're burning mostly all fat. I don't believe external temperature really plays a roll in the whole process of glycogen depletion.

Hope you're headed back to school for arts fest :)

[BecomeLegendary]

Glycogen is still going to deplete during LISS though. Just at a smaller percentage of total calories than it would if you were doing HIIT. I guess it's not so much the glycogen depletion I am asking about though, I'm more interested in if there have been any studies done or anyone knows if the body burns more calories when performing cardio outside in the heat and humidity compared to inside on a treadmill?

[RandyJH]

I would go ahead and assume that you would burn more calories running in hot humid weather. My reasoning is that your body is forced to work harder in an attempt to cool you down. This cooling down process would likely cause you to expend more calories.

I am not totally sure the significance that this would have tho. It may be very minimal.

That's just the way I would look at it tho. I would be interested to read a study on this though.

[Wowzer]

One question I have had for a very long time is how much faster do glycogen levels plummit when doing LISS outside vs on a treadmill. I did LISS for 40 mins outside yesterday in 90 degree heat with very high humidity. Sure I sweat a ton, but does anyone know if there is some sort of coefficient for how many more calories are burned outside compared to nice and easy treadmill running?

In10City has a graph that he usually posts in these threads... I'm sure you could search for it.

In short: It has to be over about 30 degrees Celsius or below 0 degrees Celsius for temperature to significantly effect energy expenditure during exercise.

Humidity has little effect except to increase the amount of water you lose when sweating. The process of sweating itself doesn't use much energy.

[BecomeLegendary]

I would go ahead and assume that you would burn more calories running in hot humid weather. My reasoning is that your body is forced to work harder in an attempt to cool you down. This cooling down process would likely cause you to expend more calories.

I am not totally sure the significance that this would have tho. It may be very minimal.

That's just the way I would look at it tho. I would be interested to read a study on this though.

Yeah man I think its a given that your going to burn more outside in the heat and humidity, I was just wondering if there were any studies done or if there is any coefficient that is close to the actual difference.

[caa5000]

Yeah man I think its a given that your going to burn more outside in the heat and humidity, I was just wondering if there were any studies done or if there is any coefficient that is close to the actual difference.

randy just told you that there wasn't much difference...

[in10city]

the lower the intensity, the less glycogen that is used. Chances are you're burning mostly all fat. I don't believe external temperature really plays a roll in the whole process of glycogen depletion.

Hope you're headed back to school for arts fest :)
Temperature can alter substrate usage patterns. Of course there are a number of factors that would influence this.

http://www.biochemsoctrans.org/bst/031/1270/0311270.pdf

The US Military also has publications on nutritional needs in cold & hot environments which discuss alterations and acclimation effects so you can further look to quality this.

As a side note, a recent study "Decreased energy expenditure during prolonged sub-maximal exercise in a warm environment" showed that the increase in energy expenditure for exercise is reduced in a warm environment when compared to median and cold environments but substrate utilization estimated from RER were not.

[rhizome]

Temperature can alter substrate usage patterns. Of course there are a number of factors that would influence this.

http://www.biochemsoctrans.org/bst/031/1270/0311270.pdf

The US Military also has publications on nutritional needs in cold & hot environments which discuss alterations and acclimation effects so you can further look to quality this.

As a side note, a recent study "Decreased energy expenditure during prolonged sub-maximal exercise in a warm environment" showed that the increase in energy expenditure for exercise is reduced in a warm environment when compared to median and cold environments but substrate utilization estimated from RER were not.
Looks like I'm gonna stop running with a sweat vest on! :(

[BecomeLegendary]

randy just told you that there wasn't much difference...

Yeah I posted that reply the second he posted his reply so I didn't read it before I saw what he had to say. Thanks for the input all, I will check for those graphs and read those articles.