Too much cardio?

I doubt you are burning that many calories and, unless you experience symptoms of overtraining, it's not "too much".

The biggest potential drawback of doing ANY high-volume routine--regardless of the activity--is that, because of the energy required to keep up the workouts, you start doing a lot of "crap minutes"--i.e. workouts at a lower intensity or lack of focus. You want to make sure you maintain the quality of your basic workouts. If there is a conflict, that might mean losing some of the "fill in" sessions or turning them into more "activity" than "exercise".

I personally listen to my body and it will set the tone for when I need to shut it down for a rest day... (Today was that day). I train hard and eat to fuel those workouts. Even though it is itself an estimation I would still invest in a good HRM (I use a Polar FT60) to get a more accurate calorie burn.. I would be really surprised if you were burning that many calories... Best of Luck

The best advice I can give is to pay attention to the signals your body is giving you. As long as you have the time and the energy, and you're feeling good, there's no reason not to work out as much as you'd like. Professional athletes work out for hours each day so why not you? Just be sure to give yourself one complete rest day every week and pay attention to any niggling pains, beyond the occasional twinge or ache, that might become full blown injuries. These would be things like aching shins (shin splints) or joints. If you start having any kind of pain with every workout your body is telling you to slow down.

"Calories Burned" counters on any cardio machine are notoriously incorrect. They are not calibrated to YOU. Be wary with doing steady state cardio as well. There is loads of evidence out there (google it) that steady state cardio is not as effective at fat burning as HIIT (High Intensity Interval Training). HIIT is a quicker, more effective way to burn fat while preserving hard-earned muscle. I know this from experience as well. Last year I spent about an hour a day, 5 days a week doing cardio and also weight training. I didn't gain an ounce of muscle even though I was weight training. I have recently gone down to 1 or 2 HIIT sessions a week and 4 weight training sessions a week, (not to mention eating about 800 more calories) and I have never felt leaner. Cardio exercise is great, it can boost your mood and relieve stress, but just be careful with doing too much. And if you do a lot, make sure you're fueling your cardio with adequate calories. Girls are sort of brain washed to think that weight training will make them look like a man, and that doing endless amounts of cardio and eating like a bird is the only way to lose weight, I assure you, THERE IS A BETTER WAY! You will maintain your sanity and happiness by easing off the cardio, lifting heavier and eating more! I hope this helps

Thanks for the advice all, my calves actually started to hurt not so long ago which was a bit of a concern for me, definitely gonna give myself a rest

This is probably standard soreness and you don't have to stop. When I first ran more than a mile I got the same thing and couldn't walk right. Kept running and it went away in about 4 days.

You're 18. Your body can take a very heavy exercise program. Doing an hour or two a day of cardio won't begin to approach overtraining.

Ramp up carefully but you can handle running everyday and be fine. I do it and I'm twice your age.

Thanks for the advice all, my calves actually started to hurt not so long ago which was a bit of a concern for me, definitely gonna give myself a rest

I wouldn't worry about sore, achy calves or other large muscles. In my younger years I was a gymnast and competed in karate and my muscles were *always* sore. Sore muscles mean you're pushing yourself and that's not a bad thing. It's what your one rest day each week is for. The things to watch out for are sharp muscle pains, painful joints and shin splints. Those types of injuries will sideline you for weeks, if not months, if you let them get out of hand.