RESUMO
This study aimed to investigate the applicability of the Lactate Threshold (LT) to predict maximal oxygen uptake (ËVO2max) and demarcate the boundary between the moderate- to heavy-intensity domain (HRm-h) in old age in comparison to the most utilized methods. A cross-sectional validation study was conducted. Participants aged 61 to 77 performed a familiarization procedure, an incremental maximal exercise treadmill test (CPX) for ËVO2max determination, the Six-minute Walk Test (6MWT), and a discontinuous incremental field test for LT determination. Lower (P<0.01) internal effort was required for LT testing (76±8%HRmax) compared to 6MWT (92±9%HRmax). The application of the 6MWT reference equations overestimated ËVO2max by 10-23%. LTs better estimated the ËVO2max (r ≈0.90, SEE: ≈3.0] compared to the 6MWT (r=0.68, SEE=5.5). HRm-h determined by the CPX differed (20%; P=0.001) from that obtained by LT. HRm-h stratification indicated participants fall into the very light to the vigorous intensity domains. LT testing is more submaximal than the 6MWT, and is a valuable tool to estimate the ËVO2max in older male adults. Implementation of LT testing in physical activity programs might help improving the quality of aerobic exercise training in older men.
Assuntos
Limiar Anaeróbio , Teste de Esforço , Ácido Láctico , Consumo de Oxigênio , Teste de Caminhada , Humanos , Estudos Transversais , Consumo de Oxigênio/fisiologia , Masculino , Idoso , Pessoa de Meia-Idade , Ácido Láctico/sangue , Teste de Esforço/métodos , Limiar Anaeróbio/fisiologia , FemininoRESUMO
BACKGROUND/AIMS: A weight-loss diet alone or combined with a progressive resistance training program induced different adaptations on cardiometabolic risk, i.e. regional changes in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) volume distribution patterns. We hypothesized that a heterogeneous adipose tissue metabolism may exist between visceral fat at different discal levels. METHODS: Thirty-four obese women, aged 40-60 years, were randomized to three groups: a control group (n = 9), a diet group (WL; n = 12) with a caloric restriction of 500 kcal/day during 16 weeks, or a diet-plus-resistance-training group (WL+RT; n = 13) with the same caloric restriction and a 16-week resistance training of 2 sessions per week. RESULTS: The association pattern between abdominal fat depots and glucose metabolism variables showed a change from the L4-L5 region (preintervention) to VAT L2-L3 and SAT L2-L3 in the WL and WL+RT groups, respectively. It is noteworthy that accumulation of fat in the midthigh was not characterized by a more favorable lipid profile or glucose metabolism. CONCLUSION: Our results reinforce the importance of considering L2-L3 images to predict insulin resistance after a weight-loss diet, alone or combined with resistance training.
Assuntos
Restrição Calórica , Doenças Cardiovasculares/dietoterapia , Dieta Redutora , Gordura Intra-Abdominal/metabolismo , Treinamento Resistido/métodos , Adulto , Biomarcadores/sangue , Índice de Massa Corporal , HDL-Colesterol , LDL-Colesterol , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Feminino , Humanos , Insulina/sangue , Resistência à Insulina , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Obesidade/dietoterapia , Fatores de Risco , Gordura Subcutânea/metabolismoRESUMO
Increased circulating adiponectin and insulin sensitivity are usually observed after body fat loss induced by a weight-loss diet. Progressive resistance training (PRT) without a concomitant weight-loss diet significantly decreases visceral fat, thus improving insulin sensitivity. Therefore, the purpose of this study was to ascertain the effects of combined 16-week PRT and weight-loss diet on circulating adiponectin and insulin sensitivity index. Thirty-four obese (BMI: 30-40 kg/m(2)) women, aged 40-60 year, were randomized to three groups: a control group (C; n = 9); a diet group (WL; n = 12) with a caloric restriction of 500 kcal/d; and a diet plus resistance training group (WL+RT; n = 13) with the same caloric restriction as group WL and a 16-week supervised whole body PRT of two sessions/week. Both WL and WL+RT groups showed similar decreases in body mass (-6.3% and -7.7%) and visceral fat (-19.9% and -20.5%). WL resulted in an expected increase in circulating levels of adiponectin (P = 0.07) and insulin sensitivity. However, circulating total adiponectin decreased (P < 0.05) in WL+RT group, whereas an improvement in different cardiovascular risk factors (insulin sensitivity, low-density lipoprotein cholesterol (LDL-C), etc.) was observed. In conclusion, in obese women a 16-week combined PRT and weight-loss diet is accompanied by significant improvements in different cardiovascular risk factors in spite of a significant decrease of circulating adiponectin.