The influence of the intensity of treadmill walking and training status on lipoprotein metabolism in the fasted and postprandial states

SIGLEAvailable from British Library Document Supply Centre- DSC:DXN003497 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Postprandial lipemia 16 and 40 hours after low-volume eccentric resistance exercise

PURPOSE: There is evidence to suggest that muscle damage caused by resistance exercise (RE) may increase postprandial lipemia (PPL). This study examined PPL for two consecutive days after a protocol of low-volume eccentric RE that caused muscle damage. METHODS: Nine healthy, untrained male volunteers aged 27.2 ± 1.1 yr performed a session of eccentric RE consisting of eight sets of inclined leg presses at six repetition maximum with 3-min rest intervals. A high-fat meal (1.2 g fat, 1.2 g carbohydrate, 0.22 g protein, and 68.6 kJ•kg -1 body mass) was administered 16 h (day 1) and 40 h (day 2) after exercise as well as after an overnight fast with no prior exercise (control condition [C]). Venous blood samples were obtained before and hourly for 6 h after each meal. RESULTS: The duration of the exercise session (including rest intervals) was 25.6 ± 0.2 min, whereas net exercise time was 4.6 ± 0.2 min. Total energy expenditure was 0.64 ± 0.04 MJ. Serum creatine kinase and ratings of perceived muscle soreness were significantly elevated on day 1 and peaked on day 2. Triacylglycerol total area under the curve was 12.1% lower on day 1 compared with C (7.51 ± 0.99 vs. 8.54 ± 1.07 mmol•L -1•6 h -1, P < 0.02), whereas no difference existed between C and day 2. Serum insulin incremental area under the curve was significantly elevated on day 2 compared with C, indicating transient insulin resistance. CONCLUSION: These results show that low-volume eccentric RE is effective in reducing postprandial triacylglycerol concentration despite the low energy expenditure. Muscle damage does not have a detrimental effect on PPL. © 2009 by the American College of Sports Medicine

Are the reductions in triacylglycerol and insulin levels after exercise related?

Moderate exercise improves insulin sensitivity and reduces triacylglycerol (triglyceride; TG) concentrations. We hypothesized that changes in insulin sensitivity are an important determinant of exercise-induced changes in postprandial TG concentrations. Altogether, 38 men and 43 women, all of whom were normotriglyceridaemic and normoglycaemic, each underwent two oral fat tolerance tests with different pre-conditions: control (no exercise) and prior exercise (90min of exercise at 60% of maximal O2 uptake the day before). Venous blood samples were obtained in the fasting state and for 6h after a high-fat mixed meal. In the control trial there were significant correlations between log fasting TG concentration and log fasting insulin concentration (r = 0.42, P < 0.0005) and between log postprandial TG response (area under the curve) and log postprandial insulin response (r = 0.48, P < 0.0005). Prior exercise reduced the fasting TG concentration by 18.2±2.2% (mean±S.E.M.) (P < 0.0005), the postprandial TG response by 21.5±1.9% (P < 0.0005), the fasting insulin concentration by 3.8±3.1% (P < 0.01) and the postprandial insulin response by 11.9±2.5% (P < 0.0005). However, there was no relationship between the exercise-induced changes in log fasting TG and log fasting insulin (r = 0.08, P = 0.50), nor between the exercise-induced changes in log postprandial TG response and log postprandial insulin response (r = 0.04, P = 0.70). These data suggest that the reductions in fasting and postprandial TG levels elicited by a session of moderate-intensity exercise are not mediated by an increase in insulin sensitivity

The arterial communication between the gastrocnemius muscle heads: A fresh cadaveric study and clinical implications

The purpose of this investigation was to describe the anatomy of the communicating (anastomotic) vessels between the gastrocnemius muscle heads and to record the extent of their supply potential. Ensuing clinical implications are discussed. Fourteen fresh cadaveric gastrocnemius muscles were examined. Detailed dissections of the communicating vessels were facilitated after injections of methylene blue or cadaveric blood solutions through the medial, lateral, or both sural arteries. The extent of the arterial cross-supply between the muscles’ heads through these vessels was determined in eight specimens after methylene blue perfusions through the lateral sural arteries, while one specimen was examined after injection of methylene blue and yellow ink through the lateral and medial sural arteries, respectively. Communicating vessels were detected in all 14 specimens. A mean number of 5.8 vascular bundles and single vessels was found. The bundles consisted of arterioles and, as all indications suggested, of concomitant venules as well. Regarding arterial cross-supply, it was clearly evident that each head could be vascularized solely from the contralateral one, mostly through these bundles. However, even if only a part of the bundles was preserved intact, vasculature was not affected

The inferiorly based gastrocnemius muscle flap: Anatomic aspects

The arterial communication between the gastrocnemius muscle heads through their lowest anastomotic arteriole bundle alone was examined in specimens from 14 fresh cadavers. In 3 specimens, the larger vessels in close vicinity to the lowest vessels were preserved as well. Distinct communication between the arterial networks of the heads was demonstrated in all cases after injecting dyes through both sural arteries or into die lateral sural artery and the lowest anastomotic arteriole in 11 and 3 specimens, respectively. Therefore, it seems that one head can be adequately supplied from the contralateral one through their lowest anastomotic arteriole(s); nevertheless, the location of this vessel varies significantly and cannot be detected preoperatively. Measurements demonstrated that although this vessel is not found at a constant level, it is invariably detected in the lower third of the medial gastrocnemius head’s length and, in 93 percent of cases, in the lower fourth. Thus, rough preoperative planning becomes feasible. Given that the venous communication between the heads has been documented as well, the authors think that an inferiorly based flap of the medial gastrocnemius head for defects of the middle third of the tibia might be both reliable and applicable; however, for reasons of safety, the muscle heads should remain attached along their lower third