Training, detraining, and retraining effects on glycemic control and physical fitness in women with type 2 diabetes.

Little is known about the detraining and retraining effects of exercise in patients with diabetes. The purpose of the present study was to investigate the effects of training, detraining, and retraining, using a combined strength and aerobic exercise program on glycemic control in women with type 2 diabetes. Thirteen postmenopausal women with type 2 diabetes (n = 13, age: 55.8 ± 5.1 years) followed a supervised aerobic and strength training program for 9 months, which was interrupted for 3 months (detraining) and resumed again for a period of 9 months (retraining). Anthropometric characteristics, glycemic control, and physical fitness were determined at baseline and after 9, 12, and 21 months. Training induced a small reduction in body mass index (BMI: -3.3%, 95% CI -5.1 to -1.5%), a moderate decrease in fasting plasma glucose (FPG: -12.0%, 95% CI -20.70 to -3.2%), glycosylated hemoglobin (HbA1c: -4.7%, 95% CI -12.1 to 2.7%), and a large decrease in postprandial glucose (PPG: - 12.1%, 95% CI -20.2 to -4.1%). In addition, there was an increase in power output (20.2%, 95% CI 6.9 to 33.6%) and total muscle strength (33.8%, 95% CI 21.4 to 46.1%). Detraining reversed PPG, HbA1c, and physical fitness. Resumption of training, however, led to a moderate decrease in BMI (-5.4%, 95% CI -8.1 to -2.7%), PPG (-9.5%, 95% CI -19.4 to 0.3%), and HbA1c (-6.8%, 95% CI -14.1 to 0.5%), and to large changes in FPG (-20.9%, 95% CI -31.9 to -9.9%), power output (33.1%, 95% CI 17.9 to 48.4%) and total muscle strength (48.2%, 95% CI 34.0 to 62.4%) compared to baseline. Thus, systematic training improves body composition, glycemic control and physical fitness in patients with type 2 diabetes. The cessation of exercise brings about negative alterations, while retraining restores all beneficial adaptations and improves them even more. Therefore, diabetic patients should follow a regular and an uninterrupted exercise program throughout life in order to control glucose metabolism and improve health.

The effects of pre-exercise glycemic index food on running capacity.

This study examined the effects of pre-exercise food on different glycemic indexes (GI) on exercise metabolism and endurance running capacity. 9 subjects performed 3 exercise trials on different days 15 min after ingesting: lentils, (LGI), potatoes, (HGI), and placebo. Each subject ingested an equal amount of each food (1 g/kg body mass) and ran on a level treadmill for 5 min at 60%, 45 min at 70% and then at 80% of VO (2max) until exhaustion. Serum glucose concentrations were higher ( P<0.01) 15 min after the HGI trial compared to the LGI and placebo trials. In addition, serum glucose levels were higher ( P<0.05) during the LGI trial at the time of exhaustion compared to the HGI and placebo trials. Plasma insulin levels, 15 min after ingestion, were higher ( P<0.001) in the HGI trial as compared to the LGI and placebo trials. Exercise time was longer during the LGI trial ( P<0.05) compared to the placebo, but the time to exhaustion in the HGI condition did not differ from the placebo (LGI: 90.0 ± 7.9; HGI: 81.8 ± 5; placebo: 73.0 ± 6.4 min). These results suggest that lentils, the LGI food, ingested 15 min before prolonged exercise maintained euglycemia during exercise and enhanced endurance running capacity.

Alterations in maximal inspiratory mouth pressure during a 400-m maximum effort front-crawl swimming trial.

AIM: The aim of this study was to examine the changes of maximal inspiratory mouth pressure (PImax) during a 400-m front crawl swimming trial. METHODS: Eleven well-trained competitive swimmers (age: 17.6+/-0.8 years, mean+/-SE) performed a 400-m front-crawl trial with maximum effort (296.2+/-4.76 s). Then, on different days they swam a 300-m, 200-m and 100-m trials at a velocity corresponding to the 400-m trial. Measurements of PImax from residual volume at upright body position before and immediately after each trial were conducted using a portable mouth pressure meter. RESULTS: Maximal inspiratory mouth pressure did not change significantly after the 100-m and 200-m trial compared to baseline (131.8+/-9.7 and 123.7+/-10.3 vs. 140.9+/-8.9 cmH(2)O, P>0.05). However, PImax was significantly lower after the 300-m (118.8+/-7 cmH(2)O, P=0.02) and 400-m trials (118.1+/-9.9 cmH(2)O, P=0.01). CONCLUSIONS: These results indicate that during a maximum effort of 400-m front crawl, the reduction of inspiratory muscle strength occurs after 300-m. This should be considered for competitive swimming training by implementing swim race distance-specific respiratory muscle training.

Attitudes towards exercise and physical activity behaviours in Greek schoolchildren after a year long health education intervention.

OBJECTIVE: To examine the short term effects of a health education programme on Greek primary schoolchildren METHODS: The school based intervention programme was applied to 29 children in the 6th grade of the 2nd Primary School of Agios Stefanos (approximately 12,000 inhabitants); 49 pupils from the 1st Primary School constituted the control group. To assess the effectiveness of the intervention, attitude and behavioural variables were measured before and after the intervention. RESULTS: After adjustment for initial differences in the assessed variables, pupils who took part in the intervention had more positive attitudes towards physical activity than the control group and scored significantly more highly on their intention to participate in physical activity. Moreover, pupils in the intervention group reported more hours/week spent in organised physical activities than pupils in the control group (mean (SD) 3.54 (0.32) v 2.54 (0.26), p<0.020). Finally, a higher proportion of pupils in the intervention classes matched the recommendations of 60 minutes of moderate to vigorous physical activity daily (77.4% v 55.1%, p<0.043). CONCLUSIONS: Within the limitations of the study, the data show that school health education programmes have the potential to slow the age related decline in physical activity and help pupils establish lifelong, healthy physical activity patterns. Promoting healthy habits and physical activity behaviours during childhood may prevent some of the leading causes of morbidity and mortality in the Greek population, and also decrease direct healthcare costs and improve quality of life.