Ideal Heart Rates?

I'd like to know too because I'm always way above my target rate and like you I would have to really slow down to be within my range. I did notice a trainer at the gym running on the elliptical.....so I don't know?

Umm...your brother realizes that the only way to burn fat is to burn calories, right? Which fat is comprised of...calories.

The "zones" are arguable among people with different levels of fitness and goals in mind. For someone who is not used to intense routines, a higher HR will make them feel like their hearts are going to jump out of their chest. As their levels of fitness improve, they can start pushing a bit harder in order for their HR to elevate.

The simple part of it is, higher HR output will maximize the number of calories burned per minute. The length of time that your HR is extremely high, will have an effect on your body. Longer durations of an elevated HR will burn the most calories, but will also burn a bit more muscle than if you were to be at a lower HR. To maximize optimal calorie burns with the least affect on muscle tearing, HIIT routines are usually recommended. Switching from a low-moderate pace to short bursts of high intensity will shoot your HR up, then immediately follow it up with short recovery periods of low-moderate pace, then repeat.

The positive aspects of HIIT routines are that they are effective in significantly burning calories in a short amount of time, as such, you don't need to to long periods of a HIIT routine. Also, there is a bit of a thermogenic effect of having your muscles create an after-burn, so that your body is burning more calories when you're not working out. Third, you can increase your level of fitness in a faster period of time than if you were to go for longer periods of time at the same pace. Lastly, interval training allows your body to not get used to a specific routine, because once it does, it will actually take longer for your body to start burning the same amount of calories for a certain length of time; i.e. if you are at a moderate pace on the elliptical for half an hour usually, once you start losing weight and your body begins to adjust to the routine of that moderate pace, since your level of fitness will have allowed you to get used to it and may not elevate your HR as fast as it used to, you would have to increase the duration of time just to get the same amount of calories burned.

Interval training keeps your body guessing as to what's coming next, so your metabolism should remain relatively high. PM me if you would like a bit more variation of incorporating HIIT routines on the elliptical. I've used it to lose the amount of weight that I have, so I can attest to its effectiveness. Otherwise, I wish you success on your journey.