I am not sweating very much during cardio!

I am currently doing anywhere between 35-60 minutes of cardio 3-4 times per week. Right now, I mainly do the elliptical machines, alternating between the ones that use the arms, and the ones that do not. I will also walk on the treadmill. I will usually do intervals with fast walking (3.7-4.0 mph), and then slower walking with an incline for a couple of minutes.

I just do not seem to be sweating very much. In the past, I have sweated a lot in the gym, but not so much lately. The only time that I do is say when I go at a fast pace for 10 minutes and then slow down, but I almost feel like it is too slow to be doing anything in terms of progress.

I just feel like if I am not sweating, I am not doing anything. Does anyone have any ideas of what the problem could be? I am busy like everyone else, and I just do not want to go to the gym and not see results.

I don't think sweating necessarily makes that much of a difference. What does make a difference is your heart rate and breathing.  As you get more fit, you need to work harder to get a workout.  When you do intervals you should be going so hard that it's not comfortable to talk. If you feel comfortable having a conversation you're not going hard enough.  So, you should up the pace on the intervals, go on a steeper incline, or both.

Is it colder in the gym than it was in the summer?

Actually, I would say that it is colder sometimes depending on how many people are there. I think that they may not turn the heat up because it is a little more crowded this time of year.

One more question, typically how long should the intervals be? Right now I would say that I do them for 2-3 minutes, but I definitley think that I should increase the intensity. I will try that for the next few days.

Different lengths of intervals improve fitness in different ways.  One good method is to go hard for 1 minute and slower for 1-2 minutes. As you get better at it, reduce the rest. Or, go as hard as you can for 30 seconds and slower for 1 minute.  Do 4-10 of these intervals.

Do some workouts with longer intervals and some workouts with shorter, more intense ones.

Perspiration is the body's way to cool itself.  You won't sweat much working out in a cool gym.  Sweat is not a good indicator of intensity.

There are a lot of different types of intervals and they accomplish different things.  Sub-Anaerobic Threashold interval can be used to increase you Lactic Acid Threashold.  In other words, if your are doing an interval of 2 or more minutes chances are that it is Sub AT.  By extending the length of the interval you are training yourself to be able to sustain a higher intensity level for longer periods of time. 

When you do an interval above your Anaerobic Threshold you can only sustain it for a short amount of time, like 20 or 30 seconds.  By repeating intervals at this intensity with short rest in between (HIIT) your are increasing both speed and endurance.  But when done right you can/should only do a few of them.  Think of them like doing sets of heavy weights, most of the benefit is in the 1st effort after the 3rd effort you are not really getting any additional benefit.

A balance cardio program will have both types of intervals, not on the same day of course, as well as some longer lower intensity efforts and active recovery days.

Also, you may not be drinking as much water as you used to.  I find that when I drink less water through the day, I barely sweat when I work out, even if I am working out at the same intensity.

So not sweating is really your bodys way of telling you that you arent hydrated enough to be working out at that level.  So make sure that you drink water throughout the day and also during your workout.

It could be because your body is getting used to the exercise you are doing. I find that if I do the same thing for a couple of months at the gym my body will get used to it and not have to work as hard as it used to. My trainer told me to switch up my routine once I feel like it isnt as difficult anymore and now im sweating and working hard all the time, and when im not, I know im not working as hard and need to change it up!

Everyone, thank you for all of your help. I am going to try to concentrate on increasing intensity on my intervals, and I will try to get in more water as well. I feel like I drink enough, but I should probably increase my intake with the exercise.

Okay, I just got back from the gym. I did intervals on the elliptical for 40 minutes, and I was sweating within the first 9. I also increased my water intake. Thanks again for the help everyone!