During pregnancy, physiological insulin resistance increases due to endocrine factors secreted by the placenta. Gestational diabetes mellitus is an example of a common complication arising from this phenomenon, for which exercise therapy is used as standard treatment. While the acute effects of static stretching on blood glucose levels are known, the effects of dynamic stretching in a seated or supine position are unclear. This study investigated the effects of dynamic stretching in a seated or supine position on blood glucose levels in young adult women with post-load hyperglycemia wearing a maternity simulation jacket. We included 11 healthy women in the luteal phase of their menstrual cycles with blood glucose levels >140 mg/dL 30 min after glucose loading. Four exercise conditions were established: bed-stretching (BSt) involving dynamic stretching in a seated, supine, or lateral position; standing-stretching (SSt) involving dynamic stretching in a standing position; walking (W) involving treadmill walking at a comfortable speed; and control (C) involving sitting at rest. After fasting for 10–14 h, blood glucose levels were measured using self-monitoring blood glucose at baseline and every 15 min for 120 min thereafter. In the BSt and W conditions, the blood glucose levels, peaks, and area under the curve at 45 and 60 min after glucose loading were significantly lower than those in the C condition. Therefore, dynamic stretching in a seated or supine position suppressed blood glucose level elevation after glucose loading in young adult women with post-load hyperglycemia wearing a maternity simulation jacket.

Triathlon is an endurance sport that requires high aerobic capacity. Previous studies demonstrated that lower-leg vascular conductance (VC) was associated with maximal oxygen uptake. However, it is unclear whether muscular VC is greater in triathletes versus untrained individuals. To test our hypothesis that VC in skeletal muscle is greater in triathletes relative to untrained peers and is associated with higher aerobic capacity in triathletes, this study investigated 10 male triathletes (21 ± 1 years of age) and 8 untrained men (22 ± 1 years). Triathletes exhibited greater maximal oxygen uptake than their untrained counterparts (61 ± 6 vs. 39 ± 6 mL/kg/min, p < 0.01), as well as lower heart rate (54 ± 7 vs. 65 ± 9 bpm, p = 0.01) and body fat (11 ± 2 vs. 16 ± 6 %, p = 0.03). There were no detectable intergroup differences in systolic (115 ± 8 vs. 117 ± 9 mmHg, p = 0.74), mean (83 ± 6 vs. 86 ± 8 mmHg, p = 0.30), or diastolic (62 ± 6 vs. 65 ± 7 mmHg, p = 0.49) blood pressure. Lower-leg blood flow (4.2 ± 1.3 vs. 2.5 ± 0.9 mL/dL/min, p = 0.01) and VC (0.05 ± 0.01 vs. 0.03 ± 0.01 mL/dL/min/mmHg, p = 0.02) based on venous occlusion plethysmography were greater in triathletes versus untrained men. Maximal oxygen uptake was correlated with lower-leg blood flow (r = 0.70, p < 0.01) and VC (r = 0.69, p < 0.01). These results demonstrate that lower-leg VC is higher in triathletes than in untrained individuals, and it may be associated with higher aerobic capacity in triathletes relative to their untrained counterparts.

Previous attempts have been made to superimpose ultrasound images (overlapping images method). The merit of this method is that it enables capturing the entire morphology of the muscle and tendon in the longitudinal direction beyond the width of the ultrasound probe. However, the division points between tissues are identified visually, which could affect the reliability of the measurements. This study identified the division points for the overlapping images method using the following two procedures: (1) visual-only identification and (2) a combination of visual and custom-built software-based identification. Finally, the reliability of the measurements for each procedure was examined by estimating the intra- and inter-rater correlation coefficients (ICC 1.1, ICC 2.1). The lengths of the Achilles tendon, muscle-tendon unit, and gastrocnemius muscle were measured using the overlapping images method for 19 volunteers. The ICC 1.1 and ICC 2.1 scores for visual identification alone ranged between 0.61–0.91 and 0.70–0.93, respectively. The scores for the combination of visual and software-based identification ranged 0.90–0.99 and 0.58–0.96, respectively. The high intra- and inter-rater reliability in the overlapping images method was demonstrated in almost all measurements of the three tissue lengths and the applicability of overlapping images method was demonstrated. In particular, the intra-rater reliability was better when a combination of visual and custom-built software-based identification was used.