In the main study , 35 healthy , non-smoking ( 23.03.3 years ) men and women ( n = 20/15 ) underwent three exercise protocols 48-h apart , in random order : i ) maximal workload ( VO2 max ) ; ii ) relative workload ( 70 % of VO2 max/10min ) ; and iii ) absolute workload ( 75W/10min ) .