Could it be that you are using the treadmill incorrectly?
Most people think that in order to lose weight or be fit they need to go fast on the treadmill and that the speed correlates with the number of calories burnt. But, you'll get really disheartened when you realize you have run two miles and have only burnt 200 calories!
So then they really turn up the speed, and they are bored and exhausted but they really haven't met their goal in calories they wanted to burn.
The really good treadmills are the ones that can change their incline considerably. It is the same concept as increasing the resistance on a bike or other piece of exercise equipment. Suddenly each step is just a little more difficult because the muscles are actually being better utilized.
The benefit of feeling like you are jogging, or even just plain walking uphill in mud is that you are burning calories at a much faster pace. And you are actually challenging yourself, but the instant heart rate and calorie expenditure is a great ego boost at the gym.
So next time you get on the treadmill, try speed walking uphill for 20 minutes, you should be pleasantly surprised. Just make sure you bring plenty of water, especially if you plan to increase your pace to jogging.
Of course if you are already increasing the incline, you can disregard this advice.Consider then trying some fitness classes if your gym offers them, I have an on campus gym and there are yoga and zumba instructors here daily. A class may take up over an hour of your day if you include pre and post-workout stretching or cooldown, but they are nice and will provoke your more competitive side, and they can be fun and sassy too.
Also try to bring a friend to the gym! I cannot stress it enough that exercise should be fun, and that is especially true if you are tossing around kettleballs with your friend, or screaming bubble butt while squatting with a massive weight in your arms. Goof off and explore, and you won't even realize how fit you are getting.