This study examined the effects of aerobic exercise without weight loss, a hypocaloric high monounsaturated fat diet, and diet plus exercise (D+E) on total abdominal and visceral fat loss in obese ...postmenopausal women with type 2 diabetes. Thirty-three postmenopausal women (body mass index, 34.6 ± 1.9 kg/m2) were assigned to one of three interventions: a hypocaloric high monounsaturated fat diet alone, exercise alone (EX), and D+E for 14 wk. Aerobic capacity, body composition, abdominal fat distribution (magnetic resonance imaging), glucose tolerance, and insulin sensitivity were measured pre- and postintervention. Body weight (∼4.5 kg) and percent body fat (∼5%) were decreased (P < 0.05) with the D and D+E intervention, whereas only percent body fat (∼2.3%) decreased with EX. Total abdominal fat and sc adipose tissue (SAT) were reduced with the D and D+E interventions (P < 0.05), whereas visceral adipose tissue (VAT) decreased with the D+E and EX intervention, but not with the D intervention. EX resulted in a reduction in total abdominal fat, VAT, and SAT (P < 0.05) despite the lack of weight loss. The reductions in total abdominal fat and SAT explained 32.7% and 9.7%, respectively, of the variability in the changes in fasting glucose levels, whereas the reductions in VAT explained 15.9% of the changes in fasting insulin levels (P < 0.05). In conclusion, modest weight loss, through either D or D+E, resulted in similar improvements in total abdominal fat, SAT, and glycemic status in postmenopausal women with type 2 diabetes; however, the addition of exercise to diet is necessary for VAT loss. These data demonstrate the importance of exercise in the treatment of women with type 2 diabetes.
To evaluate the plasma leptin levels approximately 24 h post-exercise in control and type 2 diabetic subjects and to establish if observed changes in leptin concentrations were acute or chronic ...effects of a resistance training program.
Thirty men and women (17 controls and 13 type 2, obese diabetics, age 40-55 y) had resting blood samples drawn at 08:00 h (12 h postprandial) at the beginning of the study (pre-training), 24 h after a three repetition maximal weight lifting bout (acute) and 72 h after their last training bout of 6 weeks of resistance training (chronic). The two groups were not matched with respect to body mass index and the control subjects were not normal weight. Subjects weight-trained three times a week, for 6 weeks, for 1 h, training both the upper and lower body.
Serum leptin concentrations were significantly higher in the type 2 diabetics than in the control group at pre-training (41.4+/-8.9 vs 11.4+/-3.0 ng/ml, P<0.05, respectively). Compared to pre-training, the leptin levels decreased significantly (P<0.01) after acute exercise in the diabetics but not in the control subjects (diabetics 30.9+/-7.1 vs controls 10.6+/-2.6 ng/ml). Approximately 72 h after 6 weeks of exercise training, the leptin concentrations were no longer lower than the pre-training values in either group (36.9+/-8.8 vs 11.9+/-8.8 ng/ml, respectively, P=NS). When leptin concentrations were log transformed and adjusted for fat mass there were still significant changes in leptin levels over time and between the control and diabetic group (P<0.05).
The type 2 diabetics showed a significant 30% reduction in resting leptin levels 24 h after a single bout of resistance exercise. This was an acute response to resistance exercise and not a chronic training effect (no difference between pre-training and chronic). The decreased resting leptin concentrations approximately 24 h post-acute exercise may be due to reduced glucose availability to the adipose tissue, particularly in the diabetic subjects. There is no chronic effect of resistance exercise on leptin concentrations.
Echo‐planar brain images (1.5 T, 1‐shot GRE, TR/TE=3000/45) were acquired during 30–60 s cycles of repetitive (1.3–1.7 Hz) finger flexion exercise against light (0.24) vs heavy (1.40 kg) weights. In ...protocols during which exercise was alternated with periods of rest, active voxels were identified in the contralateral motor and somatosensory areas by cross‐correlation against an on–off waveform. However, there was no significant difference between the responses to light vs heavy weights. In a continuous repetitive exercise protocol, in which only the weights were cycled, no force‐correlated voxels were identified. Inasmuch as force‐correlated neurons are known to be present in the primate cortex, the results illustrate a potential limitation of functional MRI studies based on the BOLD effect.
Astronauts experience Postflight disturbances in postural and locomotor control due to sensorimotor adaptation to the unique environment of spaceflight. These alterations might have adverse ...consequences if a rapid egress were required following a Mars landing or on return to Earth after a water landing. Currently, no operational countermeasure is targeted to mitigate Postflight balance and locomotor dysfunction.
Udermann et al evaluate the effectiveness of three exercise protocols designed to elicit delayed onset muscle soreness (DOMS) in the lumbar extensor muscles. Results indicate that exercises that ...emphasized eccentric muscle action elicits significant DOMS in the lumbar extensor muscles.
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