Combining supervised run interval training or moderate-intensity continuous training with the diabetes prevention program on clinical outcomes.

PURPOSE: The present study was designed to evaluate the 16 weeks diabetes prevention program (DPP) combined with instructed run sprint interval training (INT) or moderate-intensity continuous training (MICT) on glycemic control, body composition, fitness, exercise adherence, and perceived exercise enjoyment in sedentary, adults with prediabetes. METHODS: Participants completed three weekly supervised sessions of INT (4-10 bouts of 30 s maximal sprints followed by a 4 min active recovery) or MICT (30-60 min at 45-55% HRR) exercise coupled with the DPP for 16 weeks. At baseline, 8 and 16 weeks, participants completed fitness and clinical assessments as well as questionnaires to assess group and time differences. RESULTS: Twenty-nine study participants (INT n = 17, MICT n = 12) were randomized, however, significantly (p = 0.024) more participants withdrew from the INT (n = 11) than MICT (n = 4) treatment. There was no significant difference between groups in perceived exercise enjoyment, but, the MICT group significantly improved their perceived exercise enjoyment (10.8 ± 14.2; p = 0.021) from baseline to 16 weeks. Both INT and MICT groups decreased their body weight (2.0 ± 0.8 vs. - 5.5 ± 1.4 kg; p < 0.001), BMI (- 0.6 ± 0.3 vs. - 2.1 ± 0.5 kg/m2; p < 0.001), body fat mass (1.4 ± 0.6 vs. - 4.2 ± 1.0 kg; p < 0.001), fasting glucose (- 0.09 ± 0.01 vs. - 0.18 ± 0.02 mmol/L; p = 0.020), and HbA1c (- 0.21 ± 0.09 vs. - 0.12 ± 0.12%; p = 0.001), respectively, however, the MICT had greater reductions (GxT: p ≤ 0.05) in body weight, BMI, and body fat than the INT group. CONCLUSION: Sixteen weeks of MICT is adhered to better and elicits greater improvements in body composition than INT. Nevertheless, both interventions similarly reduced fasting glucose and HbA1c in adults with prediabetes, suggesting either treatment could be effective for T2D prevention.

Trekking poles increase physiological responses to hiking without increased perceived exertion.

Trekking poles are used by hikers for improved stability and lowered leg fatigue due to increased upper body muscle involvement. However, the weight of the poles and exaggerated upper body movement when using poles may increase total energy expenditure at a given walking speed. Few studies have investigated the physiological responses of hiking with trekking poles outside the laboratory setting. The purposes of this study were to determine if trekking poles altered physiological responses to hiking on varied terrain, and whether responses between trials were dependent on the grade of the terrain. Fourteen recreational hikers completed four hiking trials over a course that included sustained sections of flat (0 +/- 1% grade), steep uphill (>10% grade), gradual uphill (5% grade), gradual downhill (-5% grade) and steep downhill (<-10% grade) terrain. Subjects walked at a self-selected speed that was matched across trials using time-splits and a metronome. Two trials were conducted with hiking poles and two without poles. [latin capital V with dot above]O2 was significantly elevated (p <0.05) during the pole trials (1502.9 +/- 510.7 ml/min) compared to the no-pole trials (1362.4 +/- 473.2 ml/min). Similarly, ventilatory efficiency ([latin capital V with dot above]E) (43.1 +/- 9.6; 38.3 +/- 10.1 L/min) and heart rate (HR) (112.1 +/- 9.7; 105.7 +/- 10.4 bt/min) were significantly higher during the pole trials than the no-pole trials. However, ratings of perceived exertion (RPE) was not altered by pole condition (8.5 +/- 0.7; 8.4 +/- 0.8). Comparisons within each grade revealed significantly higher physiological responses for [latin capital V with dot above]O2, [latin capital V with dot above]E and HR in the pole-condition at all grades, with no significant variable*grade interactions. RPE measures were not significantly different between pole trials at any grade. These data suggest that trekking poles may be a beneficial tool for increasing caloric expenditure, as energy production increased during exercise without increased perceptions of effort.

Controlled warm-up intensity enhances hip range of motion.

Acute effects of active and passive warm-up, proprioceptive neuromuscular facilitation (PNF), and ratings of perceived exertion (RPE) were compared during hip-joint range of motion (ROM). Two active warm-up treatments included (a) achieving a respiratory exchange ratio (RER) of 1.00 and (b) achieving 60% of heart rate reserve (HRR). Hydrocollator pads (HP) served as the passive warm-up treatment. These treatments and a control were randomly assigned to increase hamstring muscle temperature of the dominant leg. Warm-up treatments were administered to 12 men (mean 25.3 years) with a minimum of 24 hours interspersed between each treatment. A timed PNF (slow-reversal-hold) technique was conducted after each warm-up treatment. Tukey tests (p < 0.05) showed ROM for RER (107.4 degrees) was greater than all other treatments. ROM for HRR (102.8 degrees) and HP (103.4 degrees) did not differ from each other but were greater than the control (98.8 degrees). Ratings of perceived exertion were lowest for RER (4.0) and highest for control (8.5). Ratings of perceived exertion for HRR (6.0) and HP (6.5) were similar. In conclusion, an active warm-up before PNF stretching appears to be the most effective treatment to increase hip ROM. Results of RPE reinforce that active warm-up reduces the resistance to stretch. In a field setting, it is estimated that a warm-up of 70% of HRR would duplicate the muscle readiness equivalent to an RER of 1.00 before PNF stretching.