Effects of two workload-matched high-intensity interval training protocols on regional body composition and fat oxidation in obese men

© 2021 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/nu13041096The effects of two high-intensity interval training (HIIT) protocols on regional body composition and fat oxidation in men with obesity were compared using a parallel randomized design. Sixteen inactive males (age, 38.9 ± 7.3 years; body fat, 31.8 ± 3.9%; peak oxygen uptake, VO2peak, 30.9 ± 4.1 mL/kg/min; all mean ± SD) were randomly assigned to either HIIT10 (48 × 10 s bouts at 100% of peak power [Wpeak] with 15 s of recovery) or HIIT60 group (8 × 60 s bouts at 100% Wpeak with 90 s of recovery), and subsequently completed eight weeks of training, while maintaining the same diet. Analyses of variance (ANOVA) showed only a main effect of time (p 0.05) in the examined parameters. Total and trunk fat mass decreased by 1.81 kg (90%CI: −2.63 to −0.99 kg; p = 0.002) and 1.45 kg (90%CI: −1.95 to −0.94 kg; p < 0.001), respectively, while leg lean mass increased by 0.86 kg (90%CI: 0.63 to 1.08 kg; p < 0.001), following both HIIT protocols. HIIT increased peak fat oxidation (PFO) (from 0.20 ± 0.05 to 0.33 ± 0.08 g/min, p = 0.001), as well as fat oxidation over a wide range of submaximal exercise intensities, and shifted PFO to higher intensity (from 33.6 ± 4.6 to 37.6 ± 6.7% VO2peak, p = 0.039). HIIT, irrespective of protocol, improved VO2peak by 20.0 ± 7.2% (p < 0.001), while blood lactate at various submaximal intensities decreased by 20.6% (p = 0.001). In conclusion, both HIIT protocols were equally effective in improving regional body composition and fat oxidation during exercise in obese men.This work is part of the research project “SAFE PATH” (Stand up And Fight obEsity: Promoting Aerobic Training and Health) and was funded by The Coca-Cola Company.Published versio

Physiological, perceptual and affective responses to high-intensity interval training using two work-matched programs with different bout duration in obese males

Objectives: This study compared physiological, perceptual, and affective responses to high-intensity interval training (HIIT) between two work-matched programs with different bout durations in obese males. Methods: Sixteen low-to-moderately active obese men completed an eight-week cycling program of supervised HIIT (3 days/week) using either short bouts [48 × 10 s at 100% of peak power output (PPO) with 15 s of recovery (HIIT10)] or long bouts [8 × 60 s at 100% PPO with 90 s of recovery (HIIT60)]. Workload was progressively adjusted, to maintain high intensity (100% PPO), throughout training. Blood lactate (BLa), heart rate (HR), ratings of perceived exertion (RPE), and feeling scale ratings (pleasure/displeasure) were measured in each HIIT session. Results: Average HR decreased in the last 2 weeks of training in both groups by 2.2 ± 1.8% of peak HR (p < 0.001). Training resulted in a reduction in BLa during exercise by 28 ± 19% (p < 0.001) from the 10th min onward only in HIIT10. Similarly, during the last weeks of training, RPE decreased (by 1.0 ± 1.1 units, p < 0.05) and feeling scale ratings were improved only in HIIT10, while RPE remained unchanged and feeling scale ratings deteriorated in HIIT60 (from 3.0 ± 1.1 to 2.1 ± 0.9 units, p < 0.001). No differences in post-exercise enjoyment were found. Conclusion: Both HIIT formats induced similar HR adaptations, but improvement of BLa, perceptual and affective responses occurred only when bout duration was shorter. Our findings suggest that, in low-to-moderately active obese men, HIIT may be more effective in improving metabolic, perceptual, and affective responses when shorter, rather than longer, bouts of exercise are used. © 2022 The Society of Chinese Scholars on Exercise Physiology and Fitnes

Physiological, perceptual and affective responses to high-intensity interval training using two work-matched programs with different bout duration in obese males

Objectives: This study compared physiological, perceptual, and affective responses to high-intensity interval training (HIIT) between two work-matched programs with different bout durations in obese males. Methods: Sixteen low-to-moderately active obese men completed an eight-week cycling program of supervised HIIT (3 days/week) using either short bouts [48 × 10 s at 100% of peak power output (PPO) with 15 s of recovery (HIIT10)] or long bouts [8 × 60 s at 100% PPO with 90 s of recovery (HIIT60)]. Workload was progressively adjusted, to maintain high intensity (100% PPO), throughout training. Blood lactate (BLa), heart rate (HR), ratings of perceived exertion (RPE), and feeling scale ratings (pleasure/displeasure) were measured in each HIIT session. Results: Average HR decreased in the last 2 weeks of training in both groups by 2.2 ± 1.8% of peak HR (p &lt; 0.001). Training resulted in a reduction in BLa during exercise by 28 ± 19% (p &lt; 0.001) from the 10th min onward only in HIIT10. Similarly, during the last weeks of training, RPE decreased (by 1.0 ± 1.1 units, p &lt; 0.05) and feeling scale ratings were improved only in HIIT10, while RPE remained unchanged and feeling scale ratings deteriorated in HIIT60 (from 3.0 ± 1.1 to 2.1 ± 0.9 units, p &lt; 0.001). No differences in post-exercise enjoyment were found. Conclusion: Both HIIT formats induced similar HR adaptations, but improvement of BLa, perceptual and affective responses occurred only when bout duration was shorter. Our findings suggest that, in low-to-moderately active obese men, HIIT may be more effective in improving metabolic, perceptual, and affective responses when shorter, rather than longer, bouts of exercise are used. © 2022 The Society of Chinese Scholars on Exercise Physiology and Fitnes

Effects of two workload-matched high-intensity interval training protocols on regional body composition and fat oxidation in obese men

The effects of two high-intensity interval training (HIIT) protocols on regional body composition and fat oxidation in men with obesity were compared using a parallel randomized design. Sixteen inactive males (age, 38.9 ± 7.3 years; body fat, 31.8 ± 3.9%; peak oxygen uptake, VO2peak, 30.9 ± 4.1 mL/kg/min; all mean ± SD) were randomly assigned to either HIIT10 (48 × 10 s bouts at 100% of peak power [Wpeak ] with 15 s of recovery) or HIIT60 group (8 × 60 s bouts at 100% Wpeak with 90 s of recovery), and subsequently completed eight weeks of training, while maintaining the same diet. Analyses of variance (ANOVA) showed only a main effect of time (p &amp;lt; 0.01) and no group or interaction effects (p &amp;gt; 0.05) in the examined parameters. Total and trunk fat mass decreased by 1.81 kg (90%CI: −2.63 to −0.99 kg; p = 0.002) and 1.45 kg (90%CI: −1.95 to −0.94 kg; p &amp;lt; 0.001), respectively, while leg lean mass increased by 0.86 kg (90%CI: 0.63 to 1.08 kg; p &amp;lt; 0.001), following both HIIT protocols. HIIT increased peak fat oxidation (PFO) (from 0.20 ± 0.05 to 0.33 ± 0.08 g/min, p = 0.001), as well as fat oxidation over a wide range of submaximal exercise intensities, and shifted PFO to higher intensity (from 33.6 ± 4.6 to 37.6 ± 6.7% VO2peak, p = 0.039). HIIT, irrespective of protocol, improved VO2peak by 20.0 ± 7.2% (p &amp;lt; 0.001), while blood lactate at various submaximal intensities decreased by 20.6% (p = 0.001). In conclusion, both HIIT protocols were equally effective in improving regional body composition and fat oxidation during exercise in obese men. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Attenuated Metabolic and Cardiorespiratory Responses to Isoenergetic High-Intensity Interval Exercise of Short Versus Long Bouts

Purpose To compare the metabolic, cardiorespiratory and perceptual responses to three isoenergetic high-intensity interval exercise (HIIE) protocols of different bout duration and an isoenergetic continuous exercise protocol. Methods Eleven healthy males (age, 28 ± 6 yr) performed four 20-min cycling trials of equal mean power output 1 wk apart. Participants cycled either continuously (CON) or intermittently with 10 s (HIIE10), 30 s (HIIE30), or 60 s (HIIE60) bouts at intensities corresponding to 49% (CON) or 100% of power at peak oxygen uptake (VO2peak). Recovery intervals during the HIIE trials were 15, 45, and 90 s, respectively. Results Average VO2 was similar in the HIIE trials (2.29 ± 0.42, 2.20 ± 0.43, and 2.12 ± 0.45 L·min-1, for HIIE10, HIIE30, and HIIE60, respectively), whereas in CON (2.02 ± 0.38 L·min-1), it was lower than HIIE10 (P = 0.002) and HIIE30 (P = 0.043). Average pulmonary ventilation (VE) was higher in HIIE60 compared with HIIE10, HIIE30, and CON (75.8 ± 21.8 L·min-1 vs 64.1 ± 14.5 L·min-1, 64.1 ± 16.2 L·min-1, and 54.0 ± 12.5 L·min-1, respectively, P < 0.001). The peak values and oscillations of VO2 and VE in HIIE60 were higher compared with all other trials (P < 0.001). Blood lactate concentration was higher in HIIE60 compared with HIIE10, HIIE30, and CON from the fifth minute onward, reaching 12.5 ± 3.5, 7.2 ± 2.1, 7.9 ± 2.9, and 4.9 ± 1.6 mmol·L-1, respectively, at the end of exercise (P < 0.001). RPE was higher and affective responses were lower in HIIE60 compared with all other trials toward the end of exercise (P < 0.001). Conclusions These findings highlight the importance of bout duration in HIIE, since shorter bouts resulted in attenuated metabolic and cardiorespiratory responses, lower RPE and feelings of displeasure compared with a longer bout, despite equal total work, duration, and work-to-recovery ratio. These results may have implications for the prescription of HIIE in various populations. © Lippincott Williams & Wilkins

Bout duration in high-intensity interval exercise modifies hematologic, metabolic and antioxidant responses

Objective: This study compared hematologic, metabolic and antioxidant responses between three high-intensity interval exercise (HIIE) trials of different bout duration and a continuous exercise trial (CON), all with equal average intensity, total work, and duration. Methods: Eleven healthy young males performed four trials involving 20 min of cycling, either continuously (49% of power at VO2max, PPO), or intermittently with 48 10-s bouts (HIIE10), 16 30-s bouts (HIIE30) or 8 60-s bouts (HIIE60) at 100% PPO, with a 1:1.5 work-to-recovery ratio at 15% PPO. Venous blood was obtained before, immediately after, and 1 h post-exercise to evaluate hematologic, metabolic and antioxidant responses. Blood lactate concentration was measured in capillary blood during exercise, while urine lactate was measured before and 1 h post-exercise. Results: Post-exercise leukocyte count (mean ± SD; 9.7 ± 2.8 k μL−1), uric acid concentration (0.35 ± 0.10 mmol L−1), glucose concentration (6.56 ± 1.44 mmol L−1), and plasma volume change (−13.5 ± 4.4%) were greater in HIIE60 compared to all other trials (p &lt; 0.05). One-hour post-exercise, lymphocytes decreased below pre-exercise values in all HIIE trials, and uric acid increased in the HIIE60 trial (p &lt; 0.05). Urine lactate concentration 1 h post-exercise increased compared to pre-exercise only in HIIE60 (19-fold, p &lt; 0.001), and this was related with the higher blood lactate concentration during exercise in that trial. Conclusions: These findings highlight the importance of bout duration, given that shorter bouts of HIIE (30 s or 10 s) induce lower blood cell perturbations, metabolic stress, and antioxidant responses compared to the commonly used 1-min bouts, despite equal total work, duration, and work-to-recovery ratio. © 2022 The Society of Chinese Scholars on Exercise Physiology and Fitnes

Bout duration in high-intensity interval exercise modifies hematologic, metabolic and antioxidant responses

Objective: This study compared hematologic, metabolic and antioxidant responses between three high-intensity interval exercise (HIIE) trials of different bout duration and a continuous exercise trial (CON), all with equal average intensity, total work, and duration. Methods: Eleven healthy young males performed four trials involving 20 min of cycling, either continuously (49% of power at VO2max, PPO), or intermittently with 48 10-s bouts (HIIE10), 16 30-s bouts (HIIE30) or 8 60-s bouts (HIIE60) at 100% PPO, with a 1:1.5 work-to-recovery ratio at 15% PPO. Venous blood was obtained before, immediately after, and 1 h post-exercise to evaluate hematologic, metabolic and antioxidant responses. Blood lactate concentration was measured in capillary blood during exercise, while urine lactate was measured before and 1 h post-exercise. Results: Post-exercise leukocyte count (mean ± SD; 9.7 ± 2.8 k μL−1), uric acid concentration (0.35 ± 0.10 mmol L−1), glucose concentration (6.56 ± 1.44 mmol L−1), and plasma volume change (−13.5 ± 4.4%) were greater in HIIE60 compared to all other trials (p &amp;lt; 0.05). One-hour post-exercise, lymphocytes decreased below pre-exercise values in all HIIE trials, and uric acid increased in the HIIE60 trial (p &amp;lt; 0.05). Urine lactate concentration 1 h post-exercise increased compared to pre-exercise only in HIIE60 (19-fold, p &amp;lt; 0.001), and this was related with the higher blood lactate concentration during exercise in that trial. Conclusions: These findings highlight the importance of bout duration, given that shorter bouts of HIIE (30 s or 10 s) induce lower blood cell perturbations, metabolic stress, and antioxidant responses compared to the commonly used 1-min bouts, despite equal total work, duration, and work-to-recovery ratio. © 2022 The Society of Chinese Scholars on Exercise Physiology and Fitnes

Effects of two workload-matched high-intensity interval training protocols on regional body composition and fat oxidation in obese men

The effects of two high-intensity interval training (HIIT) protocols on regional body composition and fat oxidation in men with obesity were compared using a parallel randomized design. Sixteen inactive males (age, 38.9 ± 7.3 years; body fat, 31.8 ± 3.9%; peak oxygen uptake, VO2peak, 30.9 ± 4.1 mL/kg/min; all mean ± SD) were randomly assigned to either HIIT10 (48 × 10 s bouts at 100% of peak power [Wpeak ] with 15 s of recovery) or HIIT60 group (8 × 60 s bouts at 100% Wpeak with 90 s of recovery), and subsequently completed eight weeks of training, while maintaining the same diet. Analyses of variance (ANOVA) showed only a main effect of time (p &lt; 0.01) and no group or interaction effects (p &gt; 0.05) in the examined parameters. Total and trunk fat mass decreased by 1.81 kg (90%CI: −2.63 to −0.99 kg; p = 0.002) and 1.45 kg (90%CI: −1.95 to −0.94 kg; p &lt; 0.001), respectively, while leg lean mass increased by 0.86 kg (90%CI: 0.63 to 1.08 kg; p &lt; 0.001), following both HIIT protocols. HIIT increased peak fat oxidation (PFO) (from 0.20 ± 0.05 to 0.33 ± 0.08 g/min, p = 0.001), as well as fat oxidation over a wide range of submaximal exercise intensities, and shifted PFO to higher intensity (from 33.6 ± 4.6 to 37.6 ± 6.7% VO2peak, p = 0.039). HIIT, irrespective of protocol, improved VO2peak by 20.0 ± 7.2% (p &lt; 0.001), while blood lactate at various submaximal intensities decreased by 20.6% (p = 0.001). In conclusion, both HIIT protocols were equally effective in improving regional body composition and fat oxidation during exercise in obese men. © 2021 by the authors. Licensee MDPI, Basel, Switzerland