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

Gregory C Bogdanis; George Mastorakos; Spyridon Tsirigkakis; Pinelopi S Stavrinou; Athanasios Kabasakalis; Aimilia Mantzou; Vassilis Mougios

doi:10.1016/j.jesf.2022.03.005

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

J Exerc Sci Fit. 2022 Jul;20(3):216-223. doi: 10.1016/j.jesf.2022.03.005. Epub 2022 Apr 11.

Authors

Gregory C Bogdanis¹, George Mastorakos^{2

3}, Spyridon Tsirigkakis⁴, Pinelopi S Stavrinou⁵, Athanasios Kabasakalis⁶, Aimilia Mantzou⁷, Vassilis Mougios⁶

Affiliations

¹ School of P.E. and Sport Science, National and Kapodistrian University of Athens, Athens, Greece.
² Unit of Metabolism and Endocrinology of Physical Activity and Sport, Department of Medicine, National & Kapodistrian University of Athens, Aretaieion Hospital, Athens, Greece.
³ Unit of Endocrinology, Diabetes Mellitus and Metabolism, Aretaieion Hospital, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
⁴ Department of P.E. and Sport Science, University of Thessaly, Trikala, Greece.
⁵ Department of Life and Health Sciences, University of Nicosia, Nicosia, Cyprus.
⁶ Laboratory of Evaluation of Human Biological Performance, School of Physical Education and Sport Science, Aristotle University of Thessaloniki, Greece.
⁷ Unit of Clinical and Translational Research in Endocrinology, First Department of Pediatrics, Faculty of Medicine, National and Kapodistrian University of Athens, Aghia Sophia Children's Hospital, Athens, Greece.

Abstract

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 < 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 < 0.05). Urine lactate concentration 1 h post-exercise increased compared to pre-exercise only in HIIE60 (19-fold, p < 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.

Keywords: Glucose; Glutathione; Immune; Total antioxidant capacity; Uric acid; White blood cells.