Effective Weight Loss Workouts for People in Their 50s

Question
QUESTION: Back in the day (as in twenty years ago) I was an aerobics instructor, and loved it. About six months ago I started up again at home, and really enjoy it...but now I'm fifty and honestly, my knees are starting to creak.

Right now I usually do two hour+ long workouts of medium-impact step and dance aerobics a week, and use five pound hand weights for about fifteen minutes of the routine. I also walk at least two miles most days with my dogs, and once a week I hike 8-10 miles.
Here's the question...to be easier on my aging joints, should I break up my aerobics workouts into shorter workouts, and do them more often? Back in my aerobics days we were told that to lose weight, you should work out longer to burn fat.
Is my info out of date?

Thanks very much.

ANSWER: Hi Donna,
It sounds like you have a good routine going. I think the theory of exercising longer to burn fat has to do with heart rate training. When you exercise continually at a lower heart rate zone your body uses more stored body fat as fuel, whereas if you exercise at a higher intensity with a higher heart rate your body will burn more carbs as fuel. Breaking it up isn't going to effect that because you will still be working at the same intensity. If you feel it would be helpful for you, breaking it up is not going to be harmful at all.
I hope that helps and if it isn't clear feel free to let me know.
Sarah

---------- FOLLOW-UP ----------

QUESTION: Thanks so much for getting back to me so quickly! I'm impressed!

I'm also still a little confused (easy to do with me!) It sounds like if I want to lose weight I should exercise longer per session, but at a lower intensity?

Lower intensity is boring, but it might be easier on my joints, too...and I'd have more "recovery" days in between my two longer sessions...

but maybe I'm misinterpreting your answer?

Thanks again.

Donna

Answer
Well, there are different ways to look at it. One way is to look at the simple "calories in vs. calories out." At the end of the day you would most likely have burned the same amount of calories from doing a shorter, more intense session as doing a longer, lower intensity session. And if you burn more calories over the course of the day than you take in, you're losing weight. But, we can look at how those calories are burned. Exercising at a low intensity where you feel you could just keep going and going is going to be burning more of those calories in the form of stored body fat (yay!), whereas exercising at a higher intensity that you could not maintain for that long is burning more of those calories in the form of carbohydrates and glycogen stored in the muscles. Really, you're going to lose weight from both. If you don't like doing low intensity, you certainly don't have to. I thinki t's most important to do what you like, so you'll stick with it. You'll just have to decide if you think the joints can handle it.

Sarah