CHANGES IN RUNNING ECONOMY BY INCREASING STEP FREQUENCY CAN BE RETAINED OVER TWO WEEKS OF NO TRAINING
Quinn, T. J., Hourihan, S. E., & Dempsey, S. L. (2012). Maintenance of increased step frequency training in female runners following a period of no training. Presentation 1545 at the 59th Annual Meeting of the American College of Sports Medicine, San Francisco, California; May 29-June 2, 2012.
This study determined if a runner could retain an increased step frequency and improved running economy after 12 days of structured training followed by 14 days with no learning stimulus. Female runners (N = 10) were recruited from local races and track clubs. Ss had 5K times between 17-22 minutes within the past year and a step frequency <175 steps/min. Day 1 involved Ss running for five minutes on the treadmill at 3.4 and 3.8 m/sec at their preferred step frequency and at an optimal step frequency of 180 steps/min. VO2 was measured at the two speeds and step frequency conditions. VO2max was measured after the submaximal runs. Days 2-11 involved training on the treadmill for 15 minutes each day at the optimal step frequency (180 steps/min). A metronome helped Ss maintain the increased step frequency which was monitored using a footswitch and a BIOPAC MP100 Data Acquisition System. Days 12 and 26 involved post-training treadmill VO2 testing with no step-training. Ss were encouraged to train at the recently learned, faster step frequency.
Following training, submaximal VO2 decreased by ~3.0% (not significant), heart rate dropped ~4.0%, and step frequency was ~4.0% higher across both speeds and conditions. Following two weeks of no structured step-frequency training, the VO2 reduction was maintained (~2.9%; not significant) as were the reduced heart rate (~4.0%) and increased step frequency (~3.7%).
Implication. An increased step frequency can be maintained following a short step-frequency training program resulting in a significantly lower heart rate and improved running economy in well-trained female runners.