You do that walk every day for how long? If you have been doing this for a couple of months it should be "easy" on you to walk it. If not then I fear you are at a low point in your health and you are running a lot of risks here. If this walk is part of a diet and exercise program, then you are doing a "good thing" - however you need to consider either cutting back slightly on this walk, or taking it slower. Heart rate is a big consideration. What you are doing amounts to a cardio exercise. Cardio program work best if you hit a target heart rate and keep it up for a while. Going from rest to high heart rate for a moment then resting again is a bad idea and opens the doors for injuries and other issues. Fat and obese people can be "fit" and when you think about it their bodies are already lugging around extra weight so their muscles should have built up a bit to handle that extra mass. Yes there is give and take here and that must be considered. Sweating is possible no matter the temperature. it is a product of work. you are expending a great deal of energy climbing a hill, more so than walking around a flat block. you are fighting gravity as well as covering a distance. Some sweating should be expected. "gasping" for air is not good, breathing hard and fast is - usually, a sign of your body trying to take up more oxygen to supply the working muscles and is tied to a faster heart rate. Target Heart Rate can be calculated basically by this calculator: http://iucar.iu.edu/geninfo/walking/heartrates.htm Here is a better one that takes into consideration other factors: http://www.stevenscreek.com/goodies/hr.shtml If you prefer charts: http://www.inch-aweigh.com/targetheart.html Ideal time for maintaining the heart rate depends on where you are in your exercise program. How old you are and what you are doing. Lifting weights will increase your heart rate, however you can not maintain it for too long since the idea of weight lifting is to exhaust the muscle "quickly". Low end exercise (walking, stair climbing) you should start out for 5 minutes and gradually work your way up to 20 to 30 minutes of continued exercise maintaining a faster heart rate. It takes time for people too increase their endurance. Ideally one should start off with a shorter distance, or walk slower. Gradually adding speed or distance to the walk over a period of weeks and months. There will be some pain - that is to be expected - if you feel that the laboring is too much, then slow down, or reduce the distance and gradually work up to that point where you can "fly" up the hill with little to no laboring to do so. Walking is a great low impact exercise to lose weight. however it should be accompanied by a good diet as well. A trick to improve performance of any exercise is to eat a high carb food, such as a bread, or rice 20 minutes before the exercise which will convert into sugars that will give your body more energy to perform. more energy means less laboring to do the exercise.

Take it a little easier. Small goals, and lots of accomplishments. No huge unattainable goals, cause then you will fail, and stay obese, and unhealthy, and unhappy. Baby steps sweetie.