my58vw

I just decided to jump in and do my first set of intervals on a bike ever. I mean actually go as hard as possible to certain time period.

I did 1x 3 ratio intervals, 30 seconds off the saddle, 39 seconds on, increasing cadence on the saddle, 3 minutes to E1 and repeat. I did four sets of the 1x3 intervals, spent 22 minutes of the bike, 5 minutes of warm up and 5 minutes of cool down.

Now my reaction. My HR took 1 minute to drop from 179 (zone 5a - 5b) to 162 (zone 4) and 2.5 minutes to E1 (135 BPM). My max HR was 182 BPM (zone 5c). I was definitly anarobic past 173 BPM and was breathing hard down to 165 or so after I stopped interval, my guess is catching up on breath from the interval. At the 4th interval I could almost not finish, muscles were actually tired enough not to be able to push 39 - 11 on the trainer.

It took me about 15 minutes off the bike to return to normal after I layed down and consumed my recovery drink.

Is this a normal reaction for first time intervals or am I going too hard. I felt dizzy once I got off the bike and for a few minutes after. I was covered in sweat. I think the dizzyness has to do with me not consuming enough water. I definitly need at least 48 oz before this type of workout, I do sweat alot anyway.

Thanks in advance.