Sex-Based Differences in Acute Physiological and Psychological Responses to a Classical HIFT Tabata Protocol Modified with Short Efforts.

Background: Tabata-based High-Intensity Functional Training (HIFT) elicits hybrid adaptations in both cardiorespiratory and neuromuscular systems. However, its high Rating of Perceived Exertion (RPE) may limit its feasibility. Purpose: This study aimed to analyze the acute physiological and psychological responses to a modified low-volume Tabata-based HIFT incorporating short efforts, with a focus on potential differences between sexes. Research Design: A single low-volume modified Tabata HIFT session was performed, comprising eight rounds of four exercises (Burpees, Mountain Climbers, Jumping Jacks, and Thrusters using two 2 kg dumbbells), involving 32 efforts of 5 seconds, interspersed with 10 seconds of passive recovery (∼8 minutes). Study Sample: Sixteen healthy moderately to highly physically active young adults (9 males and 7 females [age: 28.2 ± 4.9 years; Body Mass Index [BMI]: 24.0 ± 2.6 kg·m-2]) participated in the study. Data Collection: Physiological (Heart Rate [HR], HR Variability, and HR Recovery) and psychological (Category Ratio 10 RPE Scale [CR-10 RPE], Feeling Scale [FS], Exercise Task Self-Efficacy, Intention, and Enjoyment) variables were assessed. Results: Participants spent most of the session time (∼6 minutes / 75% of exercise volume) within 90-100% of maximal HR (HRmax), presenting no significant sex-based differences in HR-related values (p > 0.05), nor in the total repetitions performed across exercises and rounds (p > 0.05). Both sexes exhibited positive Affective Valence; however, females reported higher FS scores (p < 0.05), as well as greater Intention scores for engaging in HIFT 3 and 5 times·wk-1 compared to males (p < 0.05). Conclusions: The findings suggest that the modified low-volume Tabata HIFT protocol induces high cardiorespiratory strain, is well tolerated, and that females report greater Affective Valence response and Intention to participate than males.