Which runner will have the better finishing time?

Runnings better imho. The runners I know that stick to running perform better than those that crosstrain.

Easily the cross trainer. Easy runs aren't doing much for your 10k fitness. Getting your heart rate up does.

hah wrote:

Easily the cross trainer. Easy runs aren't doing much for your 10k fitness. Getting your heart rate up does.

Do you know of any studies that support this? I don't disagree with you, I'm just wondering why more people don't train this way.

Basically I'm leaning towards subbing out some easy mileage for cross training because I see it as having the same therapeutic effect as running easily (blood flow). Plus there wouldn't be the added pounding and I could probably work a little harder on the XT activities.

I'd almost say it would come down to "an experiment of one". Look at it this way...yeah, easy runs are still running and you're banking time on the legs, which will help them build up a resistance to fatigue over the course of the training period.

On the flip side, cross training will allow you to get the heart rate up (previously mentioned) while saving the legs from the pounding they'd take in the extra mileage (also previously mentioned).

Part of me wants to make an argument for the cross trainer, as they'll have a chance to work the body in different ways (cycling works the legs differently than running, and swimming can be a great way to condition the heart and lungs while giving the core and hips a good workout as well) and, hopefully, be less prone to injury due to cutting back on the repetitive motion/pounding/loading of the leg muscles.

The other part of me says to have them look each other in the eyes when they step up to the starting line...they'll know which one will emerge victorious.

If cross training included heavy weights I'd opt for that. It's amazing how quickly weight training can make beginners faster over short distances. 10k may be a stretch though.

Great response! I did some more searching, and two of the primary arguments for running rather than cross training on recovery days are #1 fatigue resistance (like you mentioned) and #2 weight control for athletes that might have trouble maintaining racing weight.

I guess it's like you explained: the shorter the distance the more cross-training you can get away with. Closer to the marathon distance and running more is the better option.

I'm coming at this as a former high mileage runner who is finally throwing up his hands and deciding that there has to be a better way. I don't want to be that guy who is beat down and unable to run by age 45. At the same time I still want to race well, if not better, in the coming years.

Eh, I have my moments! For cross training purposes, I highly recommend finding a local spin class with an instructor that actually knows how to put people through a workout. A few years back (when I was actually focusing on my 10k training before switching to predominately marathons) I was doing spin class twice a week in conjunction with a dedicated day for hill work, a day set aside for work on the track, and a longer run day. I think I may have been hitting 35-40 miles a week but with those two spin class days I was able to work on my heart rate zones and endurance without taking the pounding I'm getting nowadays while doing a 13-miler in the middle of the week and pushing my way back up to 20 on the weekends.

Another benefit of having cross training mixed in to your regimen is that you lower the risk of losing motivation for your runs because you're "hitting up the same streets/trails/routes every day and it's just getting monotonous". Another poster mentioned strength training as well...doing explosive body weight exercises is a great way to skyrocket the heart rate for 30-45s at a time and get you comfortable with being that uncomfortable.