gaining weight from intense intervals - anyone else? page

[Sonnenblume]

I have to give you a little background: I am a femal, 32 years old and I have been competing in in middle/long distances for many years (everything between 1500 m and 10 k; some half-marathons but that is the exception). Over the years I was able to observe a weird effect: When I do not train for being in racing shape (which means I run at moderate pace and lift some heavy weights) my weight stays pretty much the same. As soon as I add some intervalls to my training (usually two times a week or one time a week plus a race at the week-end while maintaining my weight-lifting routine) I gradually gain 2-4 pounds. I do not think that it is fat for when I decrease the amount of intense running I lose it very fast and I just do not see the fat. The effect is so prominent that when I was pregnant in 2009 and learned about it when I was already 8 weeks along I told my doctor that she didn`t need to be concerned if I had lost 4 pounds at my next visit for I intented to abstain from very intense exercise...and I was right. So what is this weight made of? Something in my muscles? I am pretty sure that it isnīt actual muscle gain for I strength train and probably will not gain muscle from endurance exercise!

[yodiewan]

Maybe increased glycogen storage. I'm not sure, but I think intense exercise increases your glycogen storage capacity. I'm not sure how quickly it can be changed. For what it's worth, I usually am up a few pounds the day after an intense workout (be it sprinting or an exceptionally greuelling weight training workout).

[runnergal]

its mostly water.

When you workout your body needs extra water to heal tissues and remove waste. Also when you increase your glycogen storage every g of glycogen comes with 3-5g of water.

Yeah, if I have to take a rest week I shed 2 lbs and as soon as I start back up I gain it back.

[MalPaz]

i gain like 5 lbs over the next few days after lifting...then, it goes away and im left looking stronger. odd, but yes, i gain when i workout

[Hedonist]

Been doing intense intervals for about two months. (8 sets of 30 sec sprint followed by 90 sec of recovery.) Have gained several pounds. No indication that it is fat. Intervals are supposed to build muscle (give you a sprinter's body instead of a distance runner's). Don't imagine it's water retention. I take diuretic for CHF. Haven't heard of the glycogen storage theory. I don't understand why intervals would do that. Maybe if you did them at an endurance level.

[js290]

As soon as I add some intervalls to my training (usually two times a week or one time a week plus a race at the week-end while maintaining my weight-lifting routine) I gradually gain 2-4 pounds. I do not think that it is fat for when I decrease the amount of intense running I lose it very fast and I just do not see the fat...So what is this weight made of? Something in my muscles? I am pretty sure that it isnīt actual muscle gain for I strength train and probably will not gain muscle from endurance exercise!

Ah, discovering the fundamental point of exercise...

[Sonnenblume]

Thanks for your replies! I tend to agree with the water theory; I lose it so fast when slowing down that I think it isn`t "real" tissue of any kind...