Dispêndio energético em sessões de treino funcional em adultos residentes na cidade de Maputo – Moçambique

Abstract

Few studies have estimated the energy expenditure (EE) of functional training (FT) sessions, none of which in actual conditions in training centers or involving recreational practitioners. This information would be useful to better understand the potential of TF as a strategy to achieve adequate physical activity volumes to promote health. The objective of this Doctoral Thesis was to quantify the EE during FT sessions by means of triaxial accelerometry, in adults without previous experience with the modality, in a commercial gym in the city of Maputo (Mozambique). The relative and absolute intensity and rate of perceived effort (RPE) were also assessed. Additionally, data drom FT were compared with those derived from continuous walking sessions (WLK). Initially, EE estimated by means of accelerometers used on the wrist, leg and waist were compared with the caloric expenditure provided by indirect calorimetry measured by telemetry (n = 10 men, 25 ± 3 years, 173.0 ± 4.1 cm, 83.5 ± 15.7 Kg). Dat from this pilot study indicated that the ideal location for estimating EE using an ActiGraph GT3XTM triaxial accelerometer would be the waist (r = 0.84, P = 0.005; mean difference of accelerometry vs. calorimetry = -0.445 kcal). The sample of the main study consisted of 25 volunteers (11 men, 16 overweight/obese, 38.8 ± 9.3 years, 168.5 ± 8.5 cm, 73.9 ± 13.8 kg), who performed three FT sessions separated by 48 h intervals, the first two consisting of familiarization sessions. The FT protocol included four circuit rounds with 12 exercises performed at maximum intensity and repetitions for 20 s, with 10-s intervals between each station. The EE (kcal derived from counts) and absolute activity intensity (counts/min) were calculated from accelerometry data. The relative intensity was estimated using the reserve heart rate (%HRR) recorded by cardiotachometer, and RPE was assessed by the Borg CR-10 Scale. The WLK sessions lasted 25 min, with EE, intensity and RPE estimated by the same techniques applied in FT. FT sessions lasted 24 min on average and EE ranged between 124-292 kcal (188 ± 41 kcal), corresponding to intensities of 5-8 METs (6,1 ± 0,6 METs) and 70-80% (74 ± 8%) FCR. Both EE and %FCR remained stable throughout most FT session. The RPE increased along the circuit rounds, from values compatible with moderate to vigorous intensity. The EE was similar in FT and WLK, but the average relative intensity was higher in FT (74% vs. 55% FCR, respectively; P = 0.0001). Vigorous activities predominated vs. moderate in both FT and WLK. However, RPE was always higher in FT (Borg 5 to 8) than WLK (Borg 3 to 5). FT applied at a commercial gym in Maputo was able to elicit EE and intensity compatible with recommendations to reduce cardiometabolic risk and improve cardiorespiratory fitness in normoponderal and overweight recreational participants