[LondonGirl88]

I have started interval running this week (5 days out of 7 - ouch!) Only about 35 minutes in total with a warm up. I am wondering how this will affect my weight loss? Does anyone know if it would actually make me gain weight (muscle) or am I not doing enough? I cover about 2.8 miles each time...

I am a bit nervous for my weeks weigh in tomorrow and wondered if its best to leave it a few weeks so I dont get discouraged?

[Steve Troutman]

It'll primarily affect your weight loss via calorie expenditure. If we increase our total calorie output for the day, it *should be* easier to manage a calorie deficit, which we know is necessary if fat is to be lost.

Will it cause muscle growth?

That depends on how sedentary or trained you were before starting. If you were pretty sedentary before, especially if you're carrying a good bit of excess fat, heck, even a walking routine could invoke some muscle growth.

But the important thing to realize is that it's not going to be significant. It being the muscle growth. I wouldn't really worry about that side of the equation.

Question for you...

When you say interval training, are you meaning that you're just varying the intensity during the bout never really reaching maximal intensity? Or are you doing high intensity interval training, where the high intensity portion of the intervals is at or near maximal effort?

[LondonGirl88]

Thanks for your reply, I am basically warming up and then running for about a minute and sprinting for about 10 seconds back to walking etc... I only do this about 6/7 times but I really feel the burn. And my fitness levels beforehand were minimal, I walk to work occasionally and thats about it.

I have done this before when I was about 10lbs lighter and i lost about 2 dress sizes but my weight actually stayed the same; as i am now trying to shift those 10lbs on the scale I wouldn't want the same thing to happen again! I know its just a number but it really does matter to me to see those 10 lbs come off!

[Steve Troutman]

What if you looked exactly how you wanted but remained the same weight?

You don't have to answer that, but I don't see how what you weigh matters in the context of my question. Unless of course you are an athlete that competes in a sport where weight matters - wrestling, horse jockey, etc.

Regardless, generally speaking, I do not advocate such a unidirectional approach. It sounds like your sole mode of exercise is HIIT. My recommendation would be to spread things out a bit. Do some lower intensity conditioning work. In more importantly, throw in some resistance training as well... assuming you're interested in optimizing body composition.

[fitmom]

Just my .02 cents - I basically ran intervals all summer long (last year) and it backfired on me, big time. Yeah, I leaned out but lost a ton of muscle mass. Not to mention, feeling faint, dizzy and chronically fatigued. It took me almost a full year to correct the "problem". If I were to do it over again, I'd do intervals once a week and weight train the rest of the time.

[Steve Troutman]

Yeah, and that's sort of where I was going. Nothing but high intensity conditioning work can tend to backfire on a lot of people. I call it the jackhammer approach, and essentially it's when people run themselves into the ground with too much high intensity work.

I see it more often when people go overboard with HIIT in conjunction with resistance training... but still, it's worth mentioning.

[LovelyAndLosing]

I did HIIT last year when I was in better shape, but I only did it 2x a week (with other cardio and resistance training otherwise) ... I think 5x a week true HIIT would be really hard on your body.

[fitmom]

You definitely need adequate recovery time otherwise you risk overtraining which is not a good thing.

BTW, my hormones were affected too. My doctor basically ordered me to exercise less and eat some more. I finally listened to him and my estrogen levels went back up to normal (and so did my sex drive).