[chatmasta]

I ran 4 years of D1 cross country. Can confirm. The oft-repeated trope is "concrete is 12x harder than soft surface grass." Not sure how true that is or how the physics work, but stay away from roads. Run on the dirt on the side of them.

[acadien]

Do you (or anybody) have evidence to support this? Genuinely curious since everything I've read shows that surface doesn't matter. I understand this result is counter-intuitive but I was under the impression its a well documented result.

[chatmasta]

Nothing beyond personal experience and knowing my own body. After you run every day for 8 years of your life you tend to notice little differences in how you feel day-to-day. For example, it's not a coincidence that after three months in Houston running on only pavement, I had far more ankle/knee/plantar pains than after a season of running on trails. Also, trails have the added benefit of activating a greater diversity of muscles in your feet, because you need to "dance around the roots."

[elwell]

I would rather run on a level surface even if it is harder. You can hurt your knee or ankle rather quickly running through some fields; but that's part of the experience I guess.

[cha5e]

Running on an uneven running surface isn't bad for you at all. Most people run primarily on the roads - so if they encounter a long path with uneven terrain - the ancillary muscles that control stabilization generally tire more quickly. It's all about transitioning slowly and letting the muscles, that haven't been used very often, strengthen.

[dazc]

And also avoid running downhill.

[elwell]

Yes, running uphill is a better workout and it feels better on the knees.

[redgrange]

why? downhills are free.

[seanmcdirmid]

Not on your knees. Downhill running (and hiking) is also more anaerobic (stopping your self from falling) than aerobic (working to move up).

[chatmasta]

If you're stopping yourself from falling when running downhill, you're doing it wrong. You should be "leaning into" the hill, which is counterintuitive and feels like you're going to fall, but is way better for your knees and also faster than stopping yourself.

[seanmcdirmid]

That only works for some grades. The grades in the Bay Area are pretty steep. If you leaned into the downward slope, you would be on your face in a few seconds.

[chatmasta]

That's why you should only run down Lombard Street!

[cha5e]

You may have just misspoken but it'd be almost impossible to get any anaerobic training out of downhill running. You might be doing some muscle strengthening though.

[seanmcdirmid]

You can definitely get an anaerobic workout from downhill hiking. Running on pavement not so much, but you do use muscles to keep from falling down.