Feeling unfit.

I cant really work out why im tiring so much on the rink during practise. Is it because my skates are crap and heavy, is it that the training is getting harder and im just finding out how unfit I am or is it because i need to change my diet to give me a more sustained release of carbs during practise. I just cant seem to keep my level of fitness constant throughout my skate session.
We were practising whips again and when I was receiving them, I just couldnt seem to get enough speed up to catch my partner. My skates are fine, when skating at pace, but as soon as I speed up, they dont seem to give me enough speed.
I think I need to practise my aerobic endurance. I can hear my bike calling as I write!!! I also dont think im eating well enough to sustain me prior to a training session. Gonna have to start eating more rice and lean meat, something low GI which will sustain me for a couple of hours hard skating.
My legs still scream at me towards the end of a session, need to work more on my quads and abs to keep me squatting and lunging, also to give me more push off power. Any excuse to keep me from thinking that it is my age that is holding me back, god forbid that anyone should tell me that i cant keep up with the girls that are 10 years younger than me!
We were practising hits today - taking and giving them. My hits aren't that bad, managed to knock some girls on their asses. Also managed to get knocked on my ass a few times - there are some girls that are like brick walls when it comes to hitting them! I hope that they are in my team when it comes to it - I wouldn't like to see them coming at me on the rink!
My knee is a little better - can now skate in low position without pain. Still tiger balming it every night and have now got a knee gasket for extra support which is helping a lot.
I cant believe that it is coming up to the end of our fresh meat. Its a bit scary to think that we are going in with the league next month, more milestones to aspire to!! Harder hits to take and faster girls to keep up with!!