Triathlon - New guy with newbie type questions

Dumb question time....So I am pretty much a newbie when it comes to TT racing. I am an avid road and mountain biker and put in a few thousand miles a year. Earlier this season I got in a few 10 mile TT runs. I was riding my carbon road bike with aero bars and doing avg speeds of like 21-21.5. I decided to get a TT bike and have some fun with it. I went to a local tri shop and got an entry level Quintana Roo Tequilo. Made a few upgrades, nicer wheels, etc. Anyway, I had a professional fitting and did a TT the next day for my first ride on the bike. Yeah, I know that wasn't brilliant, but I figured what the heck right...

First thing I noticed is that staying in the aero position for even ten miles isn't exactly second nature. It is going to take some practice to get comfortable like that. I seemed to have a bit of trouble with air intake. Is this normal or maybe a "fitting" issue?

Secondly and what I thought was a bit strange is that like 3 miles in, my legs felt like I hadn't been riding all season. On my old bike, my legs were never an issue. It felt like it was the beginning of the riding season all over...the next morning, my legs were sore...something that never happened before.

My guess is that the position of the TT bike utilizes different muscle groups? Is it for power, endurance, something else?

TT bikes are supposed to let you use your running muscles.

Getting comfortable in any new riding position takes time. After a few rides, staying in the aero position becomes much easier. Yes, your tri setup has you incorporating some different muscles. Don't worry, you'll get used to all of it quickly.

TT bikes are supposed to let you SAVE your running muscles.

Fixed.

The it will take a while to build muscle in the new position, soon you will be adjusted though.

First thing I noticed is that staying in the aero position for even ten miles isn't exactly second nature. It is going to take some practice to get comfortable like that. I seemed to have a bit of trouble with air intake. Is this normal or maybe a "fitting" issue?

Are you not able to expand your diaphram in the aero position? Are your legs hitting your stomach to prevent it, or are you really hunched over?


Secondly and what I thought was a bit strange is that like 3 miles in, my legs felt like I hadn't been riding all season. On my old bike, my legs were never an issue. It felt like it was the beginning of the riding season all over...the next morning, my legs were sore...something that never happened before.

My guess is that the position of the TT bike utilizes different muscle groups? Is it for power, endurance, something else?

It all depends on how you were riding on your road bike. Sounds like you were riding in a relatively relaxed set-back position and are moving to a more agressive and forward position on your TT bike, which is very typical. Assuming the fitter knew you were doing triathlons, he would have set your saddle more forward than for straight road TT racers, as you want to utilize alternate muscle fibers to leave more muscle for the run portion, where you can't change what muscles you use. So now you are using those alternate muscle fibers you weren't using before. You could have your saddle more set back if you have a race coming up soon, but if not, work on these muscles.

TT bikes are supposed to let you use your running muscles.

I'm only in this forum because kuf was telling me she was posting here. It's amazing that it didn't take long to find this gem.

I'm being nicer, so I'll leave it at that.