It is well evidenced in the literature that fasting aerobic exercise generates a series of metabolic differences when compared to exercise performed in the fed state, including the use of fats predominantly as an energy source. Consequently, increases in adaptations to aerobic training, related to health and physical performance, are observed when sessions are performed in the fasted state. In relation to resistance training, the evidence is limited. There is a lack of data in the literature regarding the effects of fasting on resistance exercises and whether this practice may reflect in losses or improvements in morphological and neuromuscular adaptations related to resistance training. Thus, the aim of the present project is to compare the effects of resistance training performed in the fasted state compared to the fed state during 12 weeks on body composition and physical performance in young adults. Thirty-four eutrophic or overweight individuals, not engaged in regular resistance exercises, aged between 20 and 40 years, will be recruited. They will be put on a standard customized diet and will perform 2 weekly sessions of resistance exercise after overnight fasting (10 to 12 hours) or in the fed state, for 12 weeks. Before, in the middle and after this period, evaluations of body composition, muscle thickness and quality, maximum dynamic strength and maximum power will be analyzed. Comparisons will be performed using Generalized Estimating Equations (GEE), adopting the factors group (2 stratifications) and time (3 stratifications). All results will be expressed as mean and standard deviation and the accepted significance level will be 5%.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
TRIPLE
Enrollment
28
On the first day of evaluations, the subjects will perform the basal metabolic rate (BMR) analysis, as well as familiarization with the neuromuscular tests. After the preliminary tests, the volunteers will perform the pre-intervention procedures. Assessments of body composition, muscle thickness and quality, maximum dynamic strength and maximum power will be performed. In addition, instruments related to dietary control and physical activity level will be applied. Subsequently, in a randomized manner, participants will be allocated to one of two different interventions. During the intervention (8 weeks), the adherence to the standard diet will be verified, as well as body composition, muscle thickness and quality, maximum dynamic strength and maximum power will be reassessed. After the 12 weeks of intervention, the volunteers will perform the evaluations referring to the post-intervention moment, following the same steps of the pre-intervention collections.
On the first day of evaluations, the subjects will perform the basal metabolic rate (BMR) analysis, as well as familiarization with the neuromuscular tests. After the preliminary tests, the volunteers will perform the pre-intervention procedures. Assessments of body composition, muscle thickness and quality, maximum dynamic strength and maximum power will be performed. In addition, instruments related to dietary control and physical activity level will be applied. Subsequently, in a randomized manner, participants will be allocated to one of two different interventions. During the intervention (8 weeks), the adherence to the standard diet will be verified, as well as body composition, muscle thickness and quality, maximum dynamic strength and maximum power will be reassessed. After the 12 weeks of intervention, the volunteers will perform the evaluations referring to the post-intervention moment, following the same steps of the pre-intervention collections.
Escola de Educação Física, Fisioterapia e Dança - UFRGS
Porto Alegre, Rio Grande do Sul, Brazil
Body mass
Body mass will be measured using a scale (Urano, Canoas, Brazil).
Time frame: 1 minute
Lean body mass
Lean body mass will be determined using the dual energy X-ray absorption (DEXA) method, using a densitometry machine (Hologic GE, Bedford, USA).
Time frame: 15 minutes
Fat body mass
Fat body mass will be determined using the dual energy X-ray absorption (DEXA) method, using a densitometry machine (Hologic GE, Bedford, USA).
Time frame: 15 minutes
Muscle thickness
Muscle thickness will be evaluated through ultrasound (Nemio XG, Toshiba, Japan).
Time frame: 30 minutes
Muscle quality
Muscle quality will be evaluated through echo intensity of the quadriceps through ultrasound (Nemio XG, Toshiba, Japan).
Time frame: 30 minutes
Maximum dynamic strength
Maximum dynamic strength will be assessed using the 1 repetition maximum (1RM) test for bench press and knee extension exercises.
Time frame: 30 minutes
Maximum power
The maximum power and the medium power will be evaluated in the bench press and knee extension exercises considering a load of 30 and 70% of 1RM.
Time frame: 30 minutes
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.