Combined effects of exercise and different levels of acute hypoxic severity: A randomized crossover study on glucose regulation in adults with overweight

Effects of exercise modality combined with moderate hypoxia on blood glucose regulation in adults with overweight

Purpose: This study aimed to investigate the combined effects of moderate hypoxia with three different exercise modes on glucose regulation in healthy overweight adults. Methods: Thirteen overweight males (age: 31 ± 4 years; body fat 26.3 ± 3.2%) completed three exercise trials in a randomized crossover design involving 60 min cycling exercise at 90% lactate threshold (LOW), sprint interval training (20 × 4 s all-out; SIT) and lower limb functional bodyweight exercises (8 sets of 4 × 20 s; FEX) under moderate hypoxia (FiO2 = 16.5%). Post-exercise oral glucose tolerance test (OGTT) was performed following each trial. Heart rate, oxygen saturation (SpO2), physical activity enjoyment scale (PACES), and perceptual measures were recorded during each exercise session. Venous blood was collected pre-, immediately post-, and 24 h post-exercise and analysed for plasma glucose and insulin, incremental area under curve (iAUC), and circulating microRNA expression (c-miRs-486-5p, -126-5p, and -21-5p). Interstitial glucose concentrations were measured using continuous glucose monitoring (CGM). Results: Post-exercise OGTT iAUC for plasma glucose and insulin concentration were lower in SIT and LOW vs. control (p < 0.05) while post-exercise interstitial glucose iAUC and c-miRs were not different between exercise modes. Heart rate was greater in SIT vs. LOW and FEX, and FEX vs. LOW (p < 0.05), SpO2 was lower in SIT, while PACES was not different between exercise modes. Perceptual measures were greater in SIT vs. LOW and FEX. Conclusion: Acute SIT and LOW under moderate hypoxia improved post-exercise plasma insulin compared to FEX exercises. Considering SIT was also time-efficient, well tolerated, and enjoyable for participants, this may be the preferred exercise modality for improving glucose regulation in adult males with overweight when combined with moderate hypoxia.

The function of previously unappreciated exerkines secreted by muscle in regulation of neurodegenerative diseases

The initiation and progression of neurodegenerative diseases (NDs), distinguished by compromised nervous system integrity, profoundly disrupt the quality of life of patients, concurrently exerting a considerable strain on both the economy and the social healthcare infrastructure. Exercise has demonstrated its potential as both an effective preventive intervention and a rehabilitation approach among the emerging therapeutics targeting NDs. As the largest secretory organ, skeletal muscle possesses the capacity to secrete myokines, and these myokines can partially improve the prognosis of NDs by mediating the muscle-brain axis. Besides the well-studied exerkines, which are secreted by skeletal muscle during exercise that pivotally exert their beneficial function, the physiological function of novel exerkines, e.g., apelin, kynurenic acid (KYNA), and lactate have been underappreciated previously. Herein, this review discusses the roles of these novel exerkines and their mechanisms in regulating the progression and improvement of NDs, especially the significance of their functions in improving NDs' prognoses through exercise. Furthermore, several myokines with potential implications in ameliorating ND progression are proposed as the future direction for investigation. Elucidation of the function of exerkines secreted by skeletal muscle in the regulation of NDs advances the understanding of its pathogenesis and facilitates the development of therapeutics that intervene in these processes to cure NDs.