I was getting my ass kicked over this on another board so I thought I'd do the time honoured thing of coming over here and asking the same question... well, actually one guy had been disagreeing with me and hasn't got back to me yet - but anyway, here goes!

Tabatas are about working the same muscle/groups. If I do push-up tabatas and vary, say as follows:

normal
wide
narrow
elevated
spiderman
one leg up
kneeling
scapula

am I varying the exercise too much for them to be achieving what tabatas set out to do, so making this just a 20-10 interval programme, OR is there not enough variation in the muscles used in push-ups so that these are still proper tabatas?!