High intensity interval training (HIIT) in running: effects on aerobic and anaerobic capacity, stress biomarkers and musculoskeletal responses in active and sedentary mice

Author(s)

Emanuel Elias Camolese Polisel

• Document type: Master's Dissertation
• Press: Limeira, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Aplicadas
• Defense date: 2020-08-28

Examining board members

Fúlvia de Barros Manchado Gobatto; Maria Cláudia Gonçalves de Oliveira; Ana Claudia Garcia de Oliveira Duarte

• Advisor: Fúlvia de Barros Manchado Gobatto; Pedro Paulo Menezes Scariot

Abstract

The intensity of exercise has been considered significant to obtain physical and sporting success. The high-intensity interval training (HIIT) is one of the outstanding proposals nowadays. In consequence, studies involving the application of HIIT aiming quality of life have attracted the attention of scientific community in current years, so this method of training has been considered an efficient alternative to sedentary or obese individuals. However, the long-term effects (positive and negative) when applied in active or sedentary organisms is unclear, especially on physiological stress, muscular, hepatic, cardiac and bone tissue adaptations. In this sense, based on previous studies we observed that the space where mice are kept can generate different levels of spontaneous physical activity (SPA) in these animals. Therefore, the present study aimed to investigate the long-term effects of HIIT on aerobic and anaerobic adaptations, SPA levels, stress biomarkers, body and availability of energetic stores, as well as bone tissue adaptations in active mice or not, according to the adopted housed space. Sixty C57BL/6J mice were divided in six groups (n = 10 animals per group): two baselines (baseline standard group (BL-SG) and baseline wide space group (BL-WG), euthanized before the start of experiment) and four others groups discriminated according to the housing space (small cage (SC) or large cage (LC)), both controlled (C) and HIIT (trained-T) (SC-C; SC-T; LC-C e LC-T, respectively). Initially, all animals were adapted to a treadmill running roller and submitted to the critical velocity (CV) protocol, that consisted in four aleatory and individualized running efforts (intensities between 17 and 35 m/min), with time limit records for aerobic and anaerobic capacity assessment, as well to the individualization of physical training. The training program was enforced and observed during 13 weeks, with a frequency of 5 week sessions. Each session was composed of 4 series of 3 repetitions, with effort of 30 seconds at 130% of CV and active recovery at 50% of CV for the same time, occurring passive recovery of 2 minutes between series. Besides that, there was a warm-up (5min) and relaxation at the same time after the main part of the session (total session was composed by 30min). Throughout the program, the acute physiological responses and the intensity were analyzed and readjusted with the reapplication of CV tests in sixth week. There was a daily record of food and water intake, and body mass at each two days. The SPA was either daily monitored, with high signals capture frequency (200Hz). After conclusion of HIIT program, the animals were euthanized and the biological material stored. Our results showed that there was no effect of HIIT on the increase of aerobic capacity, but it was positive in raising lean mass of mice independent of the housing space lived. The content of carcass fat and retroperitoneal fat were reduced for HIIT in both groups (SC and LC). Interestingly, HIIT reduces the SPA only in the SC-T group, indicating a preservation of the energy stores for the benefit of physical training. In addition, there was an improvement in tenacity for the LC-C group compared to the LC-T group, and also an increase on serum corticosterone to LC-C group compared SC-C and SC-T groups. In summary, our results show that HIIT was effective in reducing body fat and in the maintenance of lean phenotype. However, in general, a favorable environment to the active lifestyle presented more benefits to physical fitness and bone health of mice compared to the HIIT (AU)

• FAPESP's process: 18/07099-6 - High intensity interval training (HIIT) in running: effects on aerobic and anaerobic capacity, stress biomarkers, bone and muscle responses in active and sedentary mice
• Grantee: Emanuel Elias Camolese Polisel
• Support Opportunities: Scholarships in Brazil - Master