(5) DIFFERENCES IN DECELERATION IMPULSE FOLLOWING DIFFERING MODALITIES OF HIGH INTENSITY INTERVAL TRAINING (HIIT)

Muscle damage following exercise has been shown to impact jumping patterns, likely due to peripheral fatigue and delayed onset muscle soreness (DOMS).  Specifically, the deceleration impulse during a counter movement jump (CMJ) has been shown to decrease up to 48 hours after eccentric exercise.   

Purpose: To investigate the change in deceleration impulse following two differing exercise modalities (cycling and treadmill running) of high-intensity interval training (HIIT).   

Methods: Four young, healthy participants (28.3  ± 2.4 years, 2 females) completed a HR maximum (HRmax) test prior to completing HIIT protocols consisting of 4 minutes of high intensity followed by 3 minutes of active recovery repeated 4 times (4x4). The high intensity bout was defined as 80-90% of HRmax, and recovery was defined as 60-70% HRmax.   DOMS was subjectively reported using a Likert scale of 0-6 for lower extremity muscle soreness immediately post and at 24 hours after exercise. CMJs were performed immediately before, immediately after, and 1 hour and 24 hours post exercise.  CMJ data were collected using VALD ForceDecks.  All participants completed both HIIT modalities in a randomized order, with a one-week washout period between exercise bouts.  Data are presented as changes in CMJ performance and DOMS are reported as mean changes ± SD between post and 24-hour time points. Pearson’s r correlation coefficients were calculated to assess the relations between 24hr DOMS and 24hr deceleration impulses.  

Results:   After 24 hours, the average deceleration impulse (Ns) increase was 509.55% greater with the cycling (40 ± 50.06 Ns) compared to the treadmill (7.85 ± 17.65 Ns) HIIT program, with a 0.86 effect size. This change in deceleration impulse was moderately negatively correlated with DOMS following the cycling bout (r = -0.42) but was weakly negatively correlated following the treadmill bout (r = -0.02).  

Conclusions: The findings suggest that cycling HIIT could have a greater impact on eccentric CMJ performance than its treadmill counterpart.  It should be noted that the preliminary data came from an ongoing study.  However, the findings suggest that HIIT cycling may require a greater recovery time than HIIT treadmill running in participants who are novel to cycling.  Practical Applications:  The data presented here should be taken into consideration when prescribing HIIT exercise protocols for athletes, to allow for adequate recovery before further training or competition. 

Acknowledgements: None