walking.

i'm a total walker. i love walking. it's what relieves stress for me and makes me feel great. i try to walk everywhere i can. and almost everyday, i make a point of taking my dog for at least a 30 minute walk. i may not be going to a gym 3X/week, but at least i am still getting a great workout:


Walking and Building Muscles

In addition to burning fat and calories, walking builds muscles. You may have noticed that serious walkers have particularly shapely legs -- not "toothpick" legs or "thunder thighs." The reason is that walking builds, shapes, and tones muscles of the legs, hips, and buttocks.

Walking also boosts the strength and endurance of those muscles, which means you'll be able to do more with less fatigue. According to David Winter, Ph.D., professor of kinesiology at the University of Waterloo in Waterloo, Ontario, Canada, these are the main muscle groups walking affects:

Calf muscles: Walking is excellent for developing shapely calf muscles. The calf muscles provide the upward and forward momentum for the "pushoff" phase of walking, which lifts the heel off the ground.

Tibialis anterior and ankle extensor muscles: These muscles, which run along the anterior side of each shin, raise the toes and foot during the leg's forward motion (or "swing") phase. The muscles then lower the toes and foot as the heel hits the ground.

Hamstring muscles: Walking's pushoff phase (hip extension) works the hamstring muscles in the back of the thighs.

Quadriceps muscles: These muscles at the front of the thighs are used as each leg is extended.

Hip flexor muscles: The hip flexor muscles lift the thigh forward in the "swing" phase of the stride.

Buttock muscles: Rocking the hips during brisk walking works the gluteal (butt) muscles.

Abdominal muscles: Making a point of walking with natural, upright posture can strengthen the abdominal muscles.

Arm and shoulder muscles: These muscles are used when you pump your arms vigorously, up to chest or shoulder level, while walking (the left arm swings forward naturally as the right leg strides ahead, and vice versa).
Methods abound for enhancing the muscle-toning action. You can increase the involvement of the leg-lifting quadriceps by walking uphill -- and even downhill. And by lengthening your stride and walking faster, you'll demand more of the hamstrings, hip flexors, and buttocks.

(taken from:http://health.howstuffworks.com/wellness/diet-fitness/information/walking-to-lose-weight4.htm)