Reassembling the Field-based Applicability of the Lactate Threshold for Old Age.

This study aimed to investigate the applicability of the Lactate Threshold (LT) to predict maximal oxygen uptake (˙VO2max) 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 ˙VO2max 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 ˙VO2max by 10-23%. LTs better estimated the ˙VO2max (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 ˙VO2max in older male adults. Implementation of LT testing in physical activity programs might help improving the quality of aerobic exercise training in older men.

Weight-loss diet alone or combined with progressive resistance training induces changes in association between the cardiometabolic risk profile and abdominal fat depots.

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.

Resistance training improves cardiovascular risk factors in obese women despite a significative decrease in serum adiponectin levels.

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.