Think sitting on a stationary bike for hours on end is the best way to get in shape? Think again.
Active but untrained subjects (23 +/- 1 years) cycled for 1 hour at 65% of peak oxygen uptake (VO2-peak) before and after 6 weeks of either Sprint Interval Training (SIT) or Endurance Training (ET). SIT consisted of four to six rounds of 30 second full-sprint cycling with 4.5 min recovery between sprints, 3 days per week. ET consisted of 40-60 min of continuous cycling at a workload at 65% effort, per day, 5 days per week. Amazingly, both protocols induced similar increases in mitochondrial markers for skeletal muscle carbohydrate and lipid oxidation, while glycogen and phosphocreatine utilization during exercise were reduced after training, and calculated rates of whole-body carbohydrate and lipid oxidation were decreased and increased, respectively, with no differences between groups.
(J. Physiol. 2008 Jan 1;586(1):151-60. Epub 2007 Nov 8.)