Monitoring training load and visual-motor adaptation using fitlight feedback in high-intensity interval training (HIIT)

Abstract Aim. This study aimed to investigate the effects of integrating Fitlight visual feedback into high-intensity interval training (HIIT) on training load, reaction performance, and executive cognitive function in healthy young adults. It was hypothesized that Fitlight-enhanced HIIT would improve neuromotor and cognitive outcomes without significantly altering cardiovascular or subjective training load Material and method . Twenty -four physically active participants (12 males, 12 females; aged 19 - 23 years) completed two HIIT sessions in a randomized crossover design: a control session (standard HIIT) and an experimental session (HIIT augmented with Fitlight visual cues) Each session consisted of eight 30-second maximal effort intervals with 30 seconds of rest. Training load was monitored using smartwatch heart rate recordings and Borg CR-10 rate of perceived exertion (RPE). Performance metrics included Fitlight-derived reaction time (RT) and movement time (MT). Cognitive function was assessed pre- and post-intervention using the Go/No-Go test (inhibitory control) and Trail Making Test-B (TMT-B, executive function). Results . Fitlight-enhanced HIIT significantly reduced RT (0.36 to 0.33 s, p = 0.001, d = 0.74) and MT (1.20 to 1.12 s, p = 0.013, d = 0.55), and improved TMT-B completion time (75.5 to 69.9 s, p = 0.048, d = 0.43). No significant differences were observed for Go/No-Go accuracy, heart rate, or RPE. Conclusions. These findings indicate that Fitlight-integrated HIIT enhances neuromotor speed and executive function without increasing physiological load, supporting its utility as a time-efficient training modality in both athletic and cognitive-performance contexts.