Eclectic...
I was reviewing your workout:
Sunday: Spinning class 1 hour, weights - arms/back
Monday: Swim 1 hour AM, Elliptical/run 1 hour PM eventually add leg weights
Tuesday: OFF day (other commitments)
Wed: Swim 45 min, weights arms/back
Thur: Elliptical/run 1 hour
Fri: bike/trainer using the Chris Carmichael time trial DVD - 1 hour
Socialize the rest of the evening I mean we DO need balance
Sat: Elliptical/run, weights - legs, eventually add swimming
Let me ask a few questions:
Why all of the elliptical training? Is it to get in extra cardio?
Why all of the swimming... aren't you a strong swimmer already? I know I am, and for sprints, I can literally train 2 times a month and come out 3rd in my age group in competition.
Are you a strong cyclists? Can you cycle outside at all? Or is it just too cold?
Is there anyway you can add 1 brick (bike to run) a week in there? That is really important. Even if it's a spin class to a treadmill. Or maybe add a run after your trainer ride on Fri? If you do that, you could probably miss the running on Sat.
Why weights for your arms/back 2 times a week? I would guess you are working different body parts, right?
With that said... you have a really aggressive workout schedule and for a sprint tri... you will be MORE than ready. Honestly, with about 4-6 hours of training a week, sprints are very doable.
Keep in mind that you need to focus on your weak areas. And the elliptical is great for the extra cardio, but won't really affect your running all that much. If you are short on time, focus on your walk/run combo over the elliptical machine.
Now, with running... the rule is that you want to up your miles running by 10% each week to keep from getting any type of injuries.
Now, I'm not an expert. I don't win my age group at tri's... and I have only done a handful of events. I'm just giving this advice based on what I experienced in my Tri 101 class and training for the past couple of years. But I am NOT an expert.
Your workout schedule does look aggressive though and you will certainly be more than ready.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"