High-intensity intermittent cycling increases purine loss compared with workload-matched continuous moderate intensity cycling

• DOI: 10.1007/s00421-014-2878-x
• Publication Date: 2014-04-18T18:05:37Z
• Authors: Tracey Gerber; Melissa Louise Borg; Alan Hayes; Christos George S...
• Keywords: Cycling; Intensity; Sports medicine; Human physiology

Exercise at 50-60 % of peak oxygen consumption (VO2 peak) stimulates maximal fat oxidation rates. Despite a lower estimated work performed; high-intensity intermittent exercise (HIIE) training produces greater mass reductions when compared with workload-matched continuous (CON) steady state exercise. No metabolic basis has been documented nor mechanisms offered to explain this anomaly. This study investigated the physiological and responses two different protocols.On separate occasions least 1 week apart, eight apparently healthy males cycled for 30 min either 50 VO2 or performed repeated 20 s bouts supramaximal 150 %VO2 separated by 40 rest (HIIE).The average heart rate, consumption, plasma glycerol free fatty acid concentrations were not during recovery between trials. Plasma lactate hypoxanthine (Hx) elevated urinary excretion rates Hx uric following HIIE as CON (P < 0.05).Exercise-induced accumulation purine are indirectly represents net loss adenosine triphosphate (ATP) from muscle. The subsequent restorative processes required intramuscular de novo replacement ATP may contribute negative energy balance in part, account potential accelerated observed programs.