Originally Posted by Dodger

The new study was conducted on 16 college-aged students who performed six training sessions over two weeks. Eight subjects performed between four and six 30-second bursts of "all out" cycling separated by 4 minutes of recovery during each training session. <snip>

"Our study demonstrates that interval-based exercise is a very time-efficient training strategy," said Gibala. “This type of training is very demanding and requires a high level of motivation. However, short bursts of intense exercise may be an effective option for individuals who cite ‘lack of time’ as a major impediment to fitness."