well, im asking two questions here:

1) I am in desperate need of something to make my leg day a little more interesting. I mean im really starting to get bored with it. The main concern, i have is that my concentration will go down enough to reflect on my performance of the actual exercises, i mean my legs are my tools as a tennis player and really dont want to screw up. Please, i need something.

2) On the up side, i have started myself on HIIT, and ive gone with a basic regimen. 90 sec jog, 30 sec sprint; 10 times over. I was just wondering if there were any better suggestions to what i could do.

Thanks very much for any help...
Believe me, it would be much appreciated.