High intensity, circuit-type integrated neuromuscular training alters energy balance and reduces body mass and fat in obese women: A 10-month training-detraining randomized controlled trial

Abstract

This randomized controlled trial examined body mass, body composition, energy balance and performance responses of previously sedentary overweight/obese women to a circuit-type integrated neuromuscular training program with alternative modalities. Forty-nine healthy overweight or class I obese females (36.4±4.4 yrs) were randomly assigned to either a control (N = 21), training (N = 14) or training-detraining (N = 14) group. In weeks 1-20, the training groups trained three times/week using 10-12 whole-body exercises of progressively increased intensity/volume, organized in timed interval circuit form. In weeks 21-40, the training group continued training whereas the training-detraining group not. Heart rate, perceived exertion, blood lactate, exertion, oxygen consumption and excess post-exercise oxygen consumption were measured for one session/phase/person and exercise energy expenditure was calculated. Energy intake, habitual physical activity, resting metabolic rate, body composition, body mass, strength and maximal oxygen consumption were measured at baseline, mid-intervention and post-intervention. A two-way repeated measures ANOVA was used to determine differences between three time points and three groups. In C, VO2max declined (p<0.013) and body fat (p<0.008), waist (p<0.059) and hip (p<0.012) circumferences increased after 40 weeks compared to baseline. Training reduced body mass (6%, p<0.001), body fat (~5.5%, p<0.001) and increased fat-free mass (1.2-3.4%, p<0.05), strength (27.2%, p<0.001) and endurance (26.8%, p<0.001) after a 10-month implementation period using a metabolic overload of only 5-12 metabolic equivalents of task-hours per week. Training induced a long-term negative energy balance during an exercise and a non-exercise day due to an elevation of resting metabolic rate (6%-10%, p<0.05) and exercise-related energy expenditure. Training had an 8% and 94% attrition and attendance rates, respectively. Training-induced gains were attenuated but not lost following a 5-month detraining. A 10-month implementation of a high-intensity interval type training program elicited both endurance and musculoskeletal gains and resulted in a long-term negative energy balance that induced a progressive and sustained reduction of body and fat mass.

Trial registration: ClinicalTrials.gov NCT03134781.

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1. CONSORT diagram of the study.

Fig 2. Experimental flowchart.

C, control group; TR, training group (40 weeks); TRD, training (20 weeks)—detraining (20 weeks) group; CINT, circuit integrated neuromuscular training; RMR, resting metabolic rate; 1for all groups (4-week adaptation period); 2only for TR and TRD; 3for all groups; 4acute metabolic measurements for TR and TRD (1 session per participant in each training phase: perceived exertion and heart rate measurement during the exercise session, oxygen consumption and blood lactate concentration before, during and after a session and excess post-exercise oxygen consumption after a session).

Fig 3. VO2max changes during the experimental period.

VO2max, maximal oxygen intake; *significant difference with baseline (p<0.05); ‡significant difference with the control group (p<0.05); #significant difference with previous time point (p<0.05); †significant difference between training and training-detraining groups (p<0.05).

Fig 4. 1RM changes during the experimental period.

1RM, one repetition maximum; *significant difference with baseline (p

Fig 5. Changes in daily energy balance in the control and experimental groups at pre- and mid-training.

RMR, resting metabolic rate; 1mean values for all groups; 2mean values for training and training-detraining groups.

Fig 6. Changes in daily energy balance in the experimental groups at post-training and detraining.

RMR, resting metabolic rate.