Toronto, March 15 (IANS) Now, you may no longer use the common excuse of 'lack of time' for not doing enough exercise. Researchers have found that short-term high-intensity interval training is a time efficient way of exercising.

The study, from scientists at Canada's McMaster University, adds to the growing evidence for the benefits of short-term high-intensity interval training (HIT) as a time-efficient but safe alternative to traditional types of moderate long term exercise.

Astonishingly, it is possible to get more by doing less!

'We have shown that interval training does not have to be 'all out' in order to be effective,' says Martin Gibala. 'Doing 10 one-minute sprints on a standard stationary bike with about one minute of rest in between, three times a week, works as well in improving muscle as many hours of conventional long-term biking less strenuously.'

HIT means doing a number of short bursts of intense exercise with short recovery breaks in between. The authors have already shown with young healthy college students that this produces the same physical benefits as conventional long duration endurance training despite taking much less time (and amazingly, actually doing less exercise!).

This less extreme HIT method may work well for people (the older, less fit, and slightly overweight among us) whose doctors might have worries about them exercising 'all-out'. It has been known for years that repeated moderate long-term exercise tunes up fuel and oxygen delivery to muscles and aids the removal of waste products. Exercise also improves the way muscles use the oxygen to burn the fuel in mitochondria, the microscopic power station of cells.

The 'secret' to why HIT is so effective is unclear. However, the study by Gibala and co-workers also provides insight into the molecular signals that regulate muscle adaptation to interval training. It appears that HIT stimulates many of the same cellular pathways that are responsible for the beneficial effects we associate with endurance training.

The upside of doing more exercise is well-known, but a big question for most people thinking of getting fit is: 'How much time out of my busy life do I need to spend to get the perks?'

Martin Gibala says 'no time to exercise' is not an excuse now that HIT can be tailored for the average adult. 'While still a demanding form of training,' Gibala adds, 'the exercise protocol we used should be possible to do by the general public and you don't need more than an average exercise bike.'

The study was published in the Journal of Physiology.