That is the question . . .

I'm gearing up for my first duathlon this weekend and I'm thinking about whether or not to throw a pair of clip-on aero-bars on my roadie ('00 Trek 2300). I am comfortable riding in the drops for the duration of the cycling section, and I've never ridden on aero-bars before -- I'm a bit concered that I'm not going to feel comfortable on the bike. I could get at most four rides in between now and then to get a feel for the bars; I just don't know if they're worth it.

Some of the guys I work with (I work in a bike shop) think that aero-bars aren't worth it because they constrict your breathing, so that whatever you gain in speed is offset by what you lose in aerobic capacity. I don't buy this argument (if this were true, Lance and his ilk wouldn't be out there on aero-bars in the TDF and elsewhere, trying to pair seconds off their times). Clearly you can still perform at peak levels in a sharp tuck. But can I adjust to that tuck quickly enough to make this investment worthwhile today?

The faster you weigh in on this thread, the more helpful you can be. I have to decide what I'm going to do ASAP, since throwing the bars on is going to set me back, and I'm going to need some time to get used to them.

Thanks for the opinions in advance!
Cheers.

Properly setup aero bars should not constrict your breathing, breathing should become easier once you're more comfortable.

How long is your race, and what's the terrain like? If it's short, has lots of turns, or hilly, aero bars won't really help.

afaik: aero bars can indeed constrict your breathing if you have a standard road frame. that's why tri / TT bikes have a 2-3° smaller angle (a more forward position). it opens up your upper body when your crouched in that aero position.
however: bikesetups are extremely individual.

imho (unless it's a super long du) i would not mess around with your bike setup on such short notice. (people have after all also done IMs w/o aerobars).

if you want to do tris and/or dus regularly i would then consider experimenting with your bike setup so that it works (aerobars, forward seatpost...)

Don't use them. You don't have any time riding on them and you're likely to feel uncomfortable on them. Skip the aerobars for this race and then start practicing with them and use them in the next race. That will help you to see if they provide you any benefit.

FWIW, I disagree with the guys you work with.

don't mess with your set up this close to your race. i would practice with them for a future race. on a personal note i don't like aerobars for dus but i do use them for tris.

You would probably need 5-10 rides to really get used to ride in the aero position... You simply don't have enough time....

Add them after the Du and spend some time training with them.

I do sprint duathlons and I love my aerobars. I rode with mine twice and felt comfortable with them after the second ride. The main "adjustment" with these bars is balance. It is definitley a different feel when you are steering yourslef while being stretched out over a pair of aerobars. I found that with aerobars, my average speed went up about 2mph. Beyond this, the aero position is comfortable and a welcome relief from other riding positions while racing. I do agree with the other cyclists in that proper position is key. You cannot just slap a pair of aerobars on your bike and hope they are positioned correctly. If you are not sure of proper position, take your bike and bars into your LBS and have them fit you. This should not take very long. Good luck with your race!