Hello everyone (if you saw this on KR, my apologies, but there are people here who don't post on KR and I would like their advice): I'm training for the L.A. Marathon (road race), and I have an 18 mile long run next weekend. For long runs, is it better to train on dirt or harder stuff (blacktop/concrete) to simulate race conditions? I am concerned about preventing injuries. I mainly run half marathons, and for that distance my favorite course is a hilly dirt trail near my home. I have been using that lately but it's got disadvantages (like hardly any bathrooms or water). During the 14 and 16 milers, I carried a heavy 2-bottle trail pack on my lower back; I think the extra weight may have bothered my knees but I took a few days off and knees are ok now. I also replaced my shoes, just to be safe. So for the 18 miler, I'm considering using this asphalt/concrete bike path near the beach (it's got bathrooms and water), plus I can park my car nearby and pick up supplies as I need them. I have completed one marathon in 2006 and trained mostly on harder stuff, but since then I noticed my knees are rather sensitive. I'm trying to solve as many problems as I can: I have lost 10 pounds since that marathon. I wear orthotics and neutral shoes that I replace frequently (Asics Gel Nimbus and Cumulus). I have biomechanical problems (knock knees and one leg shorter than the other) so I do alot of cross training with a personal trainer. I would appreciate your wisdom on this subject since many of you are way more experienced than I am with the full marathon. thank you in advance, dromedary p.s. I wasn't on CR very long, plus I didn't read it for half of last year so I may have missed this topic before. I appreciate all answers. You guys have way more experience than I have (or could hope to have).

Great thread gang. Dromedary, to simulate race conditions you'd need to run on the same type of surface of course. IMHO however, an off road run is more beneficial from a training standpoint for a couple reasons. First, the degree of difficulty is harder as with an undulating surface, you have to concentrate on your footstrike with each step. I learned by running the Va. Creeper Marathon how tough off road running is even on a well groomed trail. also, the impact is less and therefore less taxing on your body. All this IMHO. Spareribs, I can't identify your other 3 reasons but I did want to mention that I thoroughly enjoyed exploring your corporate website. Great job sir.

Biting tongue

Lou, I assume you are biting your tongue as there was a string on hard vs. soft surfaces some time ago on CR. I recall Jim24315 once said to me, "try dropping a golf ball on that packed dirt track you run on, and then drop one on grass and see the difference." That was convincing. I use the grass now a lot on recovery runs and now that I have some PF problems. Spareribs

Yes, this is a good experiment for those of you who run barefoot on both surfaces. I remember the response was: Put a running shoe on both surfaces. Try dropping a golf ball into a running shoe on packed dirt, and then drop one into a running shoe on grass, and see the difference. But grass vs. dirt -- I'd venture grass is softer, even with the running shoe experiment above. The earlier argument, of course, was asphalt vs. concrete.

SR - would one of the benefits of running on grass vs. harder substances be that, since you have to go slower, you can concentrate on form? Dromedary - for me, trail running would be more dangerous. I'm just so darn clumsy, and I don't pick up my feet enough, that I would injure myself by tripping and falling. Even sidewalk cracks are dangerous to me...

1. Softer impact; less wear on joints, bones 2. Strengthens ankles, dorsiflexor, other muscles 3. Irregular surfaces force you to pick your feet up, which means you have to pick your knees up, or you stumble. Same with trails. Improves form. 4. You can't run as fast on grass as you can on the roads; because you're forced to slow down, your recovery runs are slow, and easy, as they should be. Those are the ones I could think of. Any more? Spareribs

I really prefer running on trails. Perch, most of your route sounds wonderful! In the summer, I do most of my runs on trails or along bikepaths... either on the asphalt path itself, or more frequently along the shoulder of the path (usually a four-wheeler track). On these surfaces I feel I can just go on and on. BUT, I learned the hard way this fall that you do need to train for the surface you'll be running on, if possible! The Seattle Marathon is run on all roads and asphalt trails. This includes a lot of concrete and very hard pavement. My feet really took a pounding, and while I did run a PR time, my feet were sore for a day afterwards and I'd never had that happen before! This is also the problem with doing long runs on the treadmill... you get a cushioning effect on the treadmill that you don't get out on the streets.

Dromedary, the long run in marathon preparation is to get you ready for that endurance event. And some of that long run (towards the end) you should also try to get some marathon pace miles in. I don't think running on those dirt paths in PV will enable you to get either benefit; simulate LA race conditions or get up to marathon pace. Run the beach path! After the marathon, run lots of recovery miles on soft dirt or even smooth grass (if you can find it).