Effect of Heat Therapy Compared With Strength Training on Metabolic Profile, Heat Shock Response, Inflammation, Cardiovascular Responses and Microbiota in Individuals With Type 2 Diabetes

Materials and Methods Study design and setting The study is a prospective, randomized, double-blind, parallel, non-inferiority clinical trial, and will be conducted at Universidade Federal do Rio Grande do Sul, a University in Southern Brazil. This study protocol adheres to the SPIRIT recommendation.

Interventions Volunteers who meet the inclusion criteria will be guided in the study and asked to sign a written informed consent before enrollment in the trial. Participants will be randomized into intervention groups Control (C), RT or HT. In the control group, participants will not receive any intervention. In the intervention group RT, participants will perform supervised exercise in a gym on three non-consecutive days of the week. Each session will last ~60 min and will consist of a warm up, the resistance training and a cool down. All sessions will be conducted by qualified sport and exercise scientists for 12 weeks.

RT program will consist of a combination of upper and lower body exercises using gym equipments, free weights and body weight (functional exercises) as the primary resistance. The 12 weeks RT will be divided into three mesocycles of four weeks each (please see details of sets, repetitions and intervals in Table 1). Exercises will include leg press, knee extensions and leg curls, biceps curls, triceps extensions, lat pull down, shoulder press, bench press and abdominal crunch. Before the start of the training period, subjects will complete a familiarization session to practice the exercises they would further perform during the training program, when the exercise load was individually tested. The resistance training will be performed using two to three sets per exercise at intensities between 12 and 15 maximum repetitions (the heaviest possible weight to perform a total of 12-15 repetitions). The intensity of the functional exercises was controlled by OMNI scale. Each session will last 60 min.

Participants in the HT group will undertake whole body heat treatment according to previous methods. Participants will be housed in an environmental chamber initially set at 55.0oC on three non-consecutive days of the week. Each session will last 60 min. During the sessions, rectal temperature, heart rate, blood pressure and heat discomfort will be constantly measured.

Strategies for trial retention Participants will be asked once a week on the face-to-face visit to monitor their adverse events. Moreover, phone calls or messages will also be used to remember participants regarding scheduled or missed visits.