Running speed...what is considered 'good'?

what stretches do you guys do before running ? any thoughts on how much stretching you should do ?

Thanks so much guys, great info here Is it true that running is bad for the knee joints in old age, or is that just hear-say?

Running too much too fast, and increasing your distances rapidly can be really damaging for your joints. This is especially true if you're really new to fitness and carry a lot of extra weight.
Training at a reasonable pace, with enough rest days, and with gradual increases actually helps improve joint health. I can dig out the studies when I get home.
Of course, this only applies if you're healthy. If you have damaged joints or history of joint problems, that's totally different. In that case, only your doctor/ PT can tell you if running can do more harm than good for you.

Thanks so much guys, great info here Is it true that running is bad for the knee joints in old age, or is that just hear-say?

Totally false. Studies show there are no ill effects on the joints from running and it some subjects, running has improved joint health.

^^This, and I also read that running, for those with already damaged knees, may make things worse. If you don't know if you have knee damage from living, you'll know after you've been running a while! Here are some articles i dug up on this:

http://www.time.com/time/health/article/0,8599,1948208,00.html
http://thesportdigest.com/2012/04/is-running-bad-for-your-knees/

Your running speed will change over time and depends on how much weight you are carrying and how adapted your body is to it.

I've been running (and lifting) for over 30 years. I've run marathons, ultra marathons, and smaller distances.

I find it's good to a variety of running. Different distances, different speeds, some HIIT (High Intensity Interval Training) which you can look up on the web. Back in the day we just called it going to the track and doing some sprints.

I do a variety and did it all even when I was obese (the fat just slowed me down and made my back ache)

I have found that lifting weights (especially single legged exercises; one legged get ups, Bulgarian split squats, one legged dead lifts, lunges and curtsey lunges) increased my running performance as did ditching all the fat.

I ignore exercise calories so the exercise log is just to track time spent exercising for me. Exercise calories are highly over rated. You can't exercise away eating too much food. I learned this the hard way most of my life running marathon after marathon (and lifting) and not being able to lose weight and in fact continued to gain year after year. And I don't pig out, binge, snack mindlessly, eat out of boredom, etc, but the portion sizes are too big for a small person like me. (well I wasn't small when I weighed over 170 lbs at 51'0"!)

Anyway I found what worked for me was separating out the two things:

Eat less to lose weight
Exercise to maintain or build lean body mass
end of story.

Well, it did work for me. I am the fittest, leanest, strongest, and most muscular I've ever been in my life at age 51 and I'm healthy and don't get sick and have long endurance.

It really depends on your heart rate...for maximum weight loss I believe you should be getting your heart rate up to 80-85%...for me I have to increase my speed every 2 weeks in order to continue to loose weight...and you should aim for at least a 30 min run...this amount of time will allow your body to continue burning calories at the same rate for a couple of hours after running! The accepted formula for calculating your maximum heart rate is 206.9-(0.67xyour age)...hope this helps!

Oops...meant to hit "quote" and I hit "reply" instead...sorry!

For weight loss faster run,shorter time i.e sprints is better it is the equivalent of HIIT, for overall health slower and longer is purported to be better.
It ultimately depends on your running goals whether you want to be endurance ( slower/longer) or stamina (faster/shorter0

I greatly prefer intervals myself. This has been my setup the last two times:

2 minutes @ 3.3mph (warmup) [0:00 - 2:00]

1 minute @ 9.9mph
1 minute @ 6.6mph
1 minute @ 3.3mph
repeat the prior three minutes [2:00 - 8:00]

2 minutes @ 3.3mph (mid-point) [8:00 - 10:00]

1 minute @ 9.9mph
1 minute @ 6.6mph
1 minute @ 3.3mph
repeat the prior three minutes [10:00 - 16:00]

1 minute @ 3.3mph [16:00 - 17:00]

1 minute @ ~12mph [17:00 - 18:00]

2 minutes @ 3.3mph [18:00 - 20:00]

I walk 11 of the 20 minutes but I still end up pretty close to two miles in 20 minutes. I think I saw around 10:40 today when I hit the one mile mark.

You don't need to stretch if you don't want to. Unstretched muscles and tendons are better for running anyway as the energy return is decreased with stretching. You do need to warm up though with some walking and easy running before you push the pace.

I cycle now due to foot probelms - thought I cycled at a reasonable pace - 13mph over mixed terrain, pretty quick, wind blowing through my hair

13mph on a mountain bike, not bad I thought...

Until I watched a marathon and they said they were running at world record pace.

26.2 miles in 2 hours, 3 minutes

That's 13 miles an hour.......... for 26 DAMN MILES!
Just beyond belief how they can run like that

All depends on you.. measure how fast you run from when you first start your running "program" and see how much faster you get week after week.. I generally run a 9 or 10 minute mile, which is 6.7mph or 6mph respectively... but when I started I couldn't run for more than 45 secs at a time (I'm being serious!) without needing to stop for 2 mins to catch my breath.. I have terrible asthma... but now I do a 6.7mph 10min warm-up run followed by 30secs sprint as fast as I can then 30secs jog for 15 mins...

I started out by using this guide..

http://www.coolrunning.com/engine/2/2_3/181.shtml

and once I couldrun for 30 mins non-stop, I just focused on improving my speed and recovery etc

You don't need to stretch if you don't want to. Unstretched muscles and tendons are better for running anyway as the energy return is decreased with stretching. You do need to warm up though with some walking and easy running before you push the pace.

To stretch or not to stretch is a controversial subject with passionate people on both sides. It is also highly individual and for most folks it's either over or underdone. Remember though that one of the fundamental pillars of physical fitness is flexibility.

Performing a warm up is perhaps boring but is absolutely essential. Warming up does not have to be time consuming and it's actually proven to be better at preventing injuries than stretching. I prefer a combination of the two.

I would suggest that beginning runners stretch a little before/during warm up as part of it but most importantly right after a run. (hamstrings, quads, calves, shins, groin, hips) Some people require extra help with their flexibility than others. It also depends on what they were doing prior to a run. ex; worst case; a long plane ride. We need to listen to our body and individually judge if some stretching is appropriate and helpful.

There are days where I take extra time to stretch and there are other days where I don't stretch at all. But, one thing I do is to always warm up. If I don't have time to warm up I don't have time to run. I have had so many running friends through the years that just go out and run or do a small legalistic stretch and have paid for it with injuries. Some of those injuries led them to stop running altogether.