Recovery drinks ect ect ect

I have read in many threads about replenishing protien or eating carbs after a workout to compensate for musle loss. All though I kind of unserstand it I don't fully. My work out routine is usually about 1 hour of cardio 5 days a week. Basically this is my routine:

Mon - Treadmill 30 mins...elliptical 30 mins
Tues - Swim am ...an hour long masters workout totally 2000 - 3000 yds...and then in the evening I do a circuit on the Ys Cybex machines....1 set 12 reps
WED- Treadmill 30 mins...elliptical 30 mins
THUR- Swim am ...an hour long masters workout totally 2000 - 3000 yds...and then in the evening I do a circuit on the Ys Cybex machines....1 set 12 reps
Fri- Treadmill 30 mins...elliptical 30 mins
Sat- circuit on the Ys Cybex machines....1 set 12 reps
Sun - off
(I mix in a bike workout on what ever day I feel like it instead of the elliptical)

My question is....the cybex machines are supposed to be strength training and the cardio is for endurance...Do I need to be worried about muscle loss? What whould be the point of doing the cybex machines if I am losing muscle. If I loose muscle I am asumming that means I am losing strength as well. I have noticed that the tricep machine has gotten a little tougher to complete the same weight at the same number of reps (just the tricep machine). I am by no means trying to bulk up to a body builder status. I just want to increase strength, tone down and lose weight.

I don't take any supplements currently and am wondering if I should?

Krot-