calf muscles.
 

I'm no expert, and I'm sure someone can give you better advice, but my advice, if you want to do C25k, is keep walking. You have to do a lot of walking anyway with C25K, in between the running. How long have you been walking? Maybe you just need more time and you will not feel as taxed when you walk.

I just started walking last week.

You need to stretch before you walk! I usually do a bunch of stretches, but the one you should do is called the Gastroc Stretch. You can find other stretches here:
http://www.halhigdon.com/15Ktraining/Stretch.htm
I do the Gastroc Stretch, Quadriceps Stretch, and Hamstring Stretch before every walk and jog.

Thanks. I'm going to have to try them!

If the front of your calves hurt, you've got shin splints. Google that, and deal appropriately.

If it's the back of your calves, just give it time and keep walking.

Definately a lot of stretching is necessary and it took me about 2 months of doing walking dvds before I could make it through week 1 of C25K. Had to build up some muscle before I could keep my legs from going to jello!

I am going to have to strongly disagree here.

You don't want to do your stretching before your walking...you want to stretch afterwards, after the muscle is warm and pliable. You want to warm up before your walk, however, to prepare your muscles for the activity. Basically, if you walk briskly at 3.5mph, then walk the first couple of minutes at a slower pace, to warm up the muscles.

When your walk, or workout is complete-you want to do the stretching AFTERWARDS. This also goes for any exercise-running, walking, weights, etc. you want to stretch out the worked muscle after the activity.

A lot of people say stretching afterwards is better, and thats great unless you get muscle cramps while you are walking and can't do so without stretching first. This has always been the case with me (especially when jogging), and nothing besides stretching before I go and stopping to stretch again a couple of times has helped. I still start off slow and work my way up, but I also need the stretching.

Then you still need to warm up beforehand with walking, etc. for a few minutes before your initial stretch. You shouldn't stretch cold muscles.

agree you shouldnt stretch cold muscles -that is how you tear muscles, if you are prone to injury walk slower than normal pace for 5-10 minutes, THEN stretch, then do your workout, then stretch again.

If you are getting a burning stretchy pain during the walk, it might be simply a muscle weakness, pause, stretch and start again. If the pain is sharp or involves any of the joints , stop, walk slowly home and see your doc. Make sure you have good footwear.

I wouldnt (personally) start any level of running until you can comfortably walk at a brisk pace for 30-45 minutes at least 4-5 days a week. You should be able to walk pain free and not feel overly fatigued afterwards and feel like you could walk at that same intensity or higher the next day. Then you are ready to start a jog/run program like C25K.

im not going to debate whether or not its better to stretch before to after you walk... but for me the way to avoid any pain in my calfs after i work out i do the following...

drink a lot of water through out the day so that your body stays hydrated.

also, when youre done walking/working out dont just go straight into your house sit down and relax... id do a cool down of some kind whether you want to call that stretching or just a slow walk around.