While I have hiked a fair bit in the Rockie Mountain Parks, I haven't seen a bear on a trail, only off roads.
I found it interesting that, a few years ago, expert advice changed from 'playing dead' if attacked by a bear, to actually fighting back as hard as you can - if you are attacked by a bear acting predatorially, rather than defensively (e.g. a mother bear protecting cubs). But it may not always be obvious, which bear is after you.
One thing about hiking with dogs, they can scare a bear away, or bring one right to you!
I have a niece living in Banff, who hikes and runs various trails around there. Last I heard, she has had no bear incidents.... and prefers to keep it that way!

There are plenty of people who live in Jasper, Banff and Canmore who jog regularly and are still alive & uninjured. Certainly, this year especially, there have been a number of bear-human encounters, but almost none have resulted in actual contact, and the couple with contact this summer only been very minor injuries.

I have jogged in Canmore, but stayed on streets or townsite trails with good visibility where it would be hard not to see something from a long distance. I've also biked a little bit on trails, but brought bear spray.

Honestly, I wouldn't be dictating a vacation based on a tiny chance of bad bear encounter. There are places to run (and a few days with no running won't hurt anyone), and if you carry bear spray and are aware - and keep an eye on bear reports to avoid any really high risk areas - it's just fine.

Good point Kanunu. When we first started canoeing 35 years ago the theory seemed to be that bears weren't out to kill you. They wanted to get away as much as you did. Then there were a couple of awful bear attacks in Algonquin Park where it seemed the bear was out to kill. I noticed this year in the material available in the park that the advice is to fight back if it looks like a predatory bear.

Now if only the bears wore labels.

If I'm driving straight from Calgary Airport to Lake Louise, where can I buy bear spray?

And another dumb question (please remember I'm a city girl) --if you spray a bear in the face, how long is that effective? And once you spray, do you run away?

I am sure they sell it in Banff. We always stop there on our drive to Lake Louise. Good place to walk around, pick up wine, beer, a few groceries, have lunch.

We carried bear spray in Alaska but when we were in the Rockies, we never carried it. If there was bear activity, you were advised to hike in groups of 6. At Moraine Lake, there was a chalkboard where you could list your name and find other hikers to join you. We just didn't do hikes that had bear activity when it was just the two of us. There are lots of other hikes. We also saw hikers that were hiking with music playing. I imagine that was to let bears know you were coming.

If hiking alone(always let someone know where you are hiking) I would carry bear spray. You carry the spray on your belt. We test it first. Just make sure the wind is not blowing your direction. My husband tested it quite a distance from me and I still got a taste of it. It is like pepper spray. It stings your throat and makes you cough. If you sprayed it, the bear would run.

I'm sure you can buy bear spray at Wilson's right in the 'mall' at Lake Louise.

There is info and video on using bear spray here: http://www.wildsmart.ca/bearspray.htm

For Moraine Lake, you need a group of 4. Elsewhere you are fine in smaller groups, and I've hiked along without any issues.

Honestly, I'd avoid playing music - hikers go out to enjoy nature, not listen to someone else's music. I find it very irritating to be forced to listen to someone else's music when I'm hiking or climbing out in the mountains. Nature's soundtrack is just fine!! If you can't leave the iPod behind, don't come hiking (with the exception of using earbuds at night in a hut to drown out snoring!).

Thanks, Linda and kgs.

If there's bear activity reported on any trails, I'll probably just avoid them. I just don't want to be the first one to report bear activity on a trail!!

Funny, when I hiked in Alaska I was more afraid of moose than bears.

Do they have any ranger-guided hikes in the parks?

Parks Canada guided hikes:
http://www.pc.gc.ca/eng/pn-np/ab/banff/edu/guide.aspx
This is probably the first time I have heard of anyone more afraid of moose than bears - especially grizzlies! Moose attacks are very, very rare, I suggest. Actually, so are bears, or even sharks, for that matter, but one does have to be intelligent about protecting yourself - just like in 'the big city'!
Some years ago, our 3 night stay in Lake O'Hara campground was cancelled due to a bear 'attack'. A woman was hiking alone, making no noise, and climbing up a steep area on a trail. She came around a big boulder, surprised a bear right there, who swatted her, and ran. As they helicoptered her out for stitches, she was pleading with them to leave the bear alone - it was HER fault, for surprising it. Apparently that area is too small to sustain grizzlies, but they sometimes pass through.
Often, Parks Canada will close a trail down, if there is bear activity. Signs are prominently posted.

kanunu, when I was in Alaska about 6 years ago the advice about bears was still to "play dead".

Not that I ever thought I could really do that - I have no idea what I'd do - but they told us that moose will charge and outrun you and can stomp you to death and it just seemed that you might have a chance against a bear but not against a moose.

Oddly enough, a year or two later in the Tetons, several moose were spotted behind some trees by the road. A lot of cars were parked and many people were standing along the road watching them, and I joined them watching for about 15 minutes. But it was not a face to face encounter.

Thinking back, if it had been bears, I probably would not have exited my car. Maybe the other people would not have done so either.
Thanks for that link. Unfortunately I will arrive on 9/16, too late for the guided hikes.

kgs, I just had a chance to watch the bear spray video - it was good and very helpful. I'll watch it again before I leave. Thanks for the link to that site.