Effects of 7-Day Creatine Supplementation on Cognitive Function After High-Intensity Interval Training in Active Young Men

This study used a controlled pretest-posttest, four-arm interventional design to examine the effects of short-term creatine monohydrate supplementation on cognitive function after high-intensity interval training (HIIT) in active young men. Twenty participants were allocated into four groups: placebo plus exercise, placebo without exercise, creatine 0.1 g/KgBW/day plus exercise, and creatine 0.3 g/KgBW/day plus exercise. The intervention lasted 7 days.

Participants in the exercise groups completed a bodyweight HIIT protocol consisting of two rounds. Round 1 used 40 seconds of work and 20 seconds of rest, and round 2 used 30 seconds of work and 15 seconds of rest, with 30 seconds of rest between rounds. The session included 14 sequential movements and was preceded by a 5-minute warm-up and followed by a 5-minute cool-down.

Cognitive performance was assessed before and after the intervention using visual reaction time (VRT), go/no-go visual reaction time (GNGVRT), and Trail Making Test Parts A and B. These measures were selected to capture processing speed, inhibitory control, attention, and executive function. The study was approved by the ethics committee of Universitas Negeri Malang, and written informed consent was obtained from all participants.

• Creatine Monohydrate (Drug): Creatine monohydrate supplementation at a dose of 0,1 g/KgBW/day for 7 days.
• Creatine Monohydrate (Drug): Creatine monohydrate supplementation at a dose of 0,3 g/KgBW/day for 7 days.
• Placebo (Drug): Placebo supplementation for 7 days
• High Intensity Interval Training (Behavioral): A bodyweight high-intensity interval training program performed in 2 rounds with 40 seconds work and 20 seconds rest in round 1, and 30 seconds work and 15 seconds rest in round 2, with 30 seconds rest between rounds.

Primary outcomes

• Go/No-Go Visual Reaction Time False Alarm Errors [Baseline and Day 7]: Number of false alarm (commission) errors recorded during the Go/No-Go Visual Reaction Time test. Lower values indicate better inhibitory control.

Secondary outcomes

• Go/No-Go Visual Reaction Time [Baseline and Day 7]: Average response time for correct go trials during the Go/No-Go Visual Reaction Time test, expressed in milliseconds. Lower values indicate faster processing speed.
• Trail Making Test Part B Completion Time [Baseline and Day 7]: Trail Making Test Part B Completion Time
• Visual Reaction Time [Baseline and Day 7]: Simple visual reaction time measured in milliseconds. Lower values indicate faster processing speed.
• Trail Making Test Part A Completion Time [Baseline and Day 7]: Trail Making Test Part A Completion Time

Sex: Male, ages: 19 Years to 25 Years, accepts healthy volunteers

Inclusion Criteria:

* Male sport science students aged 19 to 25 years
* Physically active and accustomed to high-intensity exercise
* Healthy volunteers
* Willing to participate and provide written informed consent
* Willing to complete the 7-day intervention and cognitive testing procedures

Exclusion Criteria:

* History of cardiovascular disease
* History of kidney disease
* Current use of creatine supplements
* Current use of pre-workout supplements, steroids, or diuretics
* Any musculoskeletal, neurological, or medical condition that could interfere with exercise participation or cognitive testing
* Refusal or inability to complete the study procedures