High-Intensity Interval Resistance Training and Low-to-Moderate-Intensity Resistance Training in Upper Extremity Muscles

Resistance training is widely recognized as an effective intervention for improvingmuscle strength, functional performance, and overall health. In recent years,high‐intensity interval resistance training (HIIRT) has emerged as a time‐efficientalternative to conventional resistance training because it combines high‐load resistanceexercises with brief recovery intervals. Although previous studies have demonstrated theeffectiveness of HIIRT for improving muscular performance, evidence regardingupper‐extremity‐focused HIIRT and its effects on cognitive function, mental health, andhealth‐related quality of life remains limited.The purpose of this randomized controlled trial is to compare the effects of an 8‐weekupper‐extremity high‐intensity interval resistance training (HIIRT) program with those ofa conventional low‐to‐moderate‐intensity resistance training (LMRT) program in healthyyoung adults.A total of 49 healthy participants aged 18‐25 years will be randomly allocated to one ofthree groups: (1) HIIRT, (2) LMRT, or (3) a control group. Randomization will beperformed using age‐ and sex‐stratified block randomization. Participants in bothexercise groups will complete supervised training sessions twice weekly for eightconsecutive weeks, whereas the control group will receive no structured exerciseintervention and will be instructed to maintain their usual lifestyle.The HIIRT protocol will consist of upper‐extremity exercises performed at 80% ofone‐repetition maximum (1RM) using a cluster‐set format with short recovery intervals.The LMRT protocol will include the same exercises performed at 30‐70% of 1RM usingconventional resistance training principles. Both interventions will include exercisestargeting the biceps curl, lat pulldown, pec deck, machine shoulder press, and seatedrow.Outcome assessments will be performed before and after the 8‐week intervention. Primaryoutcomes include upper‐extremity isotonic muscle strength and functional capacityassessed by the Six‐Minute Walk Test. Secondary outcomes include cognitive functionassessed by the Montreal Cognitive Assessment, anxiety assessed by the State‐TraitAnxiety Inventory and the Generalized Anxiety Disorder‐7 questionnaire, flow stateassessed by the Dispositional Flow Scale‐2, and health‐related quality of life assessedby the Short Form‐36 Health Survey.