EFFECT OF HIGH INTENSITY INTERVAL TRAINING ON RUNNING PERFORMANCE IN LONG DISTANCE RUNNERS : A RANDOMIZED CONTROL TRIAL

K.F. Marceline¹, S. S. Holla¹, A. Mukhopadhyay¹

Background: Endurance training protocols often follow the principle of Specific Adaptations to Imposed Demands (SAID). Hence in the case of long distance runners, training mimics the race i.e., running for long distances at a low speed. This may cause considerable improvements in physiological variables that predict endurance performance in an untrained individual. However, recent studies have shown that in already conditioned athletes, increasing the volume of low to moderate intensity endurance training causes no further improvement in their endurance, performance or associated physiological variables. Studies further support that training at 70-80% of VO2max is optimal in conditioned endurance athletes. 
One such form of training is High Intensity Interval Training (HIIT) which involves high intensity bursts of activity followed by low intensity recovery. This intensity engages athletes at a higher range in their aerobic capacity and the recovery period does not last long enough for the body to return to resting state.

Purpose: There is evidence to suggest that HIIT helps improve certain physiological variables related to endurance performance but it is unclear whether these improvements translate to better sporting performance. Hence, the purpose of this study was to examine the effect of a 6-week Tabata program, a form of HIIT, on running performance in long distance runners.

Methods: Male long distance runners within the age group of 18-50 years, who have been training for a minimum of 1 year and with a 10-kilometre run time of 48+3 minutes were selected for the purpose of this study. Athletes with recent lower limb injuries, known cardiac conditions and those already engaged in HIIT were excluded. 
50 participants following the same training schedule were selected and randomly assigned to study and control groups. Their VO2max was estimated using the University of Montreal Track Test and a 10-kilometre time trial was conducted. The study group lowered their training volume by 20% and received in its place six weeks of HIIT, while the control group continued regular training. VO2max and 10-kilometre run time was tested again at the end of six weeks.

Results: t test within and between groups was done. A sub group analysis was done to study the effect of age on the outcomes. A significant difference in the VO2max (p=0.008) and 10 kilometre run time (p=0.027) was noted between the groups. A significant difference in VO2max (p=0.005) and 10 kilometre run time (p=0.011) was noted within the study group and VO2max showed a significant difference (p=0.036) within the control group. Further, on subgrouping and analysis, the participants aged between 31 to 50 years showed significant improvements (p=0.042) but their younger counterparts aged 18-30 years did not (p=0.105).

Conclusion(s): A six week HIIT program proved beneficial in improving 10-kilometre running performance in long distance runners.

Implications: HIIT may be employed in various athletic populations as a part of training and rehabilitation. A protocol of longer duration may be used to study sustained effect.

Funding, acknowledgements: This study was unfunded.

Keywords: High Intensity Interval Training, VO2max, Long Distance Runners

Topic: Sport & sports injuries

Did this work require ethics approval? Yes

Institution: Ramaiah Medical College

Committee: Ramaiah Medical College Ethics Committee [Res No ECR/215/lnst/KA/2O13/RR-16].

Ethics number: MEU-PT/EC/0512018