volume of work and oxygen consumption into the smallest amount of time. He found that intervals of 30 seconds at 90% of power output at VO2 max followed by 30 seconds of rest allowed for the highest VO2 consumption and the longest workout duration at specified intensity. Alternative protocols considered included 100% of maximum power output on the same interval schedule, similar to the Coe regimen, and 90% of maximum power output for three minutes, similar to traditional interval training. Zuniga's protocol has been implemented with great success by students of his who were participating in Creighton's Army ROTC program. Cadets completing the protocol twice a week saw greater improvements in APFT scores than in years past. Zuniga's protocol typically consists of 10 repetitions. Vollaard regimen Dr Niels Vollaard at the University of Stirling proposed that when high-intensity intervals are done at "all-out" intensities, associated health benefits plateau after performing 2 or 3 sprint repetitions. This led to the development of a 10-minute exercise routine consisting of easy pedalling interspersed with two 20-second "all-out" cycling sprints. In a 2017 meta-analysis, Vollaard indeed showed that common protocols with as many as 6 to 10 repetitions of 30-second "all-out" sprints do not improve aerobic fitness more than the "2×20-s" protocol. He shifted the terminology for his to SIT. It is claimed that this short protocol may remove many of the drawbacks that make other high-intensity interval training protocols unsuitable for the general population. In a BBC Horizon program in February 2012, Jamie Timmons, professor of systems biology at the University of Loughborough, led Michael Mosley through this exercise bike regimen, each time using three sprints instead of two. This protocol was performed three times a week for a total of 30 minutes of exercise per week (3 minutes of intense exercise), plus warm-up and recovery time. Regimen comparison A study compared HIIT of eight 1-minute bouts at 85% maximum Watts (Wmax) interspersed with 1-minute active recovery at 25% Wmax, to SIT of eight 30-second bouts at 130% Wmax interspersed with 90-second active recovery at 25% Wmax (Total time-matched at 24 minutes including warm-up & cooldown). Its conclusion was "HIIT is the recommended routine" but "the magnitude of differences in various parameters between regimens was small; therefore, preference for either modality may be up to the individual". Health effects Cardiovascular effects HIIT training and traditional endurance training both lead to significantly improved cardiovascular