Assessment of aerobic capacity during swimming exercise in ob/ob mice.

Obesity is a highly prevalent condition associated with several diseases. Physical exercise has been considered as a non-pharmacological tool in the treatment of obesity. However, several aspects underlying exercise evaluation and prescription in obesity and associated pathologies are still under investigation. Although many research involving exercise have been performed in animal models, there is a lack of protocols for aerobic capacity assessment in obese animals, such as the ob/ob mice. This study aimed the following: (i) to verify the possibility of determining the lactate threshold (LT) on swimming exercise in ob/ob mice and in non-obese heterozygote mice (ob/OB), through visual inspection (vLT) and polynomial adjustment (pLT); and (ii) to verify if the LT determined through these protocols corresponds to the maximal lactate steady state (MLSS). Eight ob/ob and ten ob/OB mice performed an incremental exercise test to determine vLT and pLT as well as constant-load exercise bouts to determine MLSS. There were no within-group differences between vLT, pLT and MLSS [ob/ob: ~5.3% body weight (BW); ob/OB: ~3·6%BW] with a high agreement among protocols. In conclusion, the identification of the LT and MLSS intensities was possible for both groups. These data suggest that the proposed protocols may be used in new research on the effects of different exercise intensities on some aspects of obesity.

Acute resistance exercise is more effective than aerobic exercise for 24h blood pressure control in type 2 diabetics.

AIM: The study aimed to analyze blood pressure (BP) responses in individuals with type 2 diabetes (T2D) over a 24h period following resistance (RES) and aerobic (AER) exercise. METHODS: Ten adults with T2D (age: 55.8 ± 7.7 years; weight: 79.4 ± 14.0 kg; fasting glucose: 133.0 ± 36.7 mg.dL⁻¹) underwent: (1) AER: 20 min of cycling at 90% lactate threshold (90% LT); (2) RES: three laps of a circuit of six exercises with eight repetitions at 70% 1-RM and 40s of recovery; and (3) a control session of no exercise. Heart rate (HR), and systolic (SBP), diastolic (DBP), mean arterial (MAP) and pulse (PP) BP, as well as lactataemia (Lac), VO(2), respiratory exchange ratio (RER) and rate of perceived exertion (RPE) were measured at rest, during exercise and control (CON) periods, and 60min after interventions. After each session, BP was also monitored over a 24h period. RESULTS: Peak Lac (RES: 6.4 ± 1.4mM; AER: 3.8 ± 1.2mM), RER (RES: 1.1 ± 0.1; AER: 0.9 ± 0.1) and RPE (RES: 14.0 ± 1.3; AER: 11.0 ± 2.3) were higher following the RES session (P < 0.05). Similar VO2 (~70% VO(2peak)) was reached during AER and RES sessions (14.0 ± 3.0 vs 14.3 ± 1.6 mL.kg.min⁻¹; P > 0.05). Compared with CON, only RES elicited post-exercise BP reduction that lasted 8h after exercise. Also, in comparison to pre-exercise rest, the BP dip during sleep was greater following RES (P < 0.05). CONCLUSION: A single exercise bout decreases BP in T2D patients over a 24h period, with RES being more effective than AER exercise for BP control.