Jonida Haxhi

Physical exercise as therapy for type 2 diabetes mellitus

Many studies have highlighted the importance of physical activity (PA) for health, and recent evidence now points to the positive improvements associated with exercise in type 2 diabetes mellitus (T2DM). However, few physicians are willing to prescribe exercise as a therapy for diabetic patients. In addition, there is a lack of information on how to implement exercise therapy especially in long‐term exercise regimens. The purpose of this manuscript is to summarize standards of exercise therapy for patients with T2DM, both in terms of prescribing and monitoring, according to the American College of Sports Medicine and the American Diabetes Association guidelines. We present details of the exercise therapies used in long‐term studies, describing how the parameters for exercise prescription were applied in clinical practice. These parameters are described in terms of frequency, intensity, duration, mode and rate of progression in long‐term therapeutic prescriptions. Individual responses to exercise dose are discussed, and critical issues to be considered in patients with underlying disease and in T2DM patients are highlighted. Copyright

Exercising for Metabolic Control: Is Timing Important?

Atherosclerosis-related cardiovascular disease and diabetes mellitus are leading causes of mortality in the world and both disorders are closely related to the postprandial phenomena. Regular exercise is being strongly advocated as a precious tool in easing the global burden of chronic disease. Although exercise intensity, duration and frequency are well established in current guidelines for healthy and diabetic individuals, there is still no consensus on the optimal timing of exercise in relation to the last meal. The present paper reviews the existing literature on the ‘when?’ of aerobic exercise for metabolic control in healthy and diabetic individuals. Effective control of postprandial phenomena might prove to be a useful tool in the prevention of chronic disease. Exercise appears to influence glycemic and triglyceridemic responses differently depending on the meal composition and time lapse from meals. In healthy individuals, fasted-state exercise favors postprandial triglyceridemic control and the insulin sensitivity related to it. However, there is a lack of data on this matter in diabetic patients. On the other hand, when postprandial glycemia is of concern, aerobic exercise works better when performed after a meal, both in healthy and in diabetic patients.

Neuromuscular Dysfunction in Diabetes: Role of Nerve Impairment and Training Status.

PURPOSE The purpose of this study was to investigate the effect of diabetes, motor nerve impairment, and training status on neuromuscular function by concurrent assessment of the torque-velocity relationship and muscle fiber conduction velocity (MFCV). METHODS Four groups were studied (n = 12 each): sedentary patients with diabetes in the first (lower) and fourth (higher) quartile of motor nerve conduction velocity (D1 and D4, respectively), trained diabetic (TD) patients, and nondiabetic sedentary control (C) subjects. Maximal isometric and isokinetic contractions were assessed over a wide range of angular velocities for the elbow flexors and knee extensors to evaluate the torque-velocity relationship. Simultaneously, MFCV was estimated from surface electromyography of the vastus lateralis and biceps brachii. RESULTS Isometric strength was similar among groups. The dynamic strength of elbow flexors was reduced in patients with diabetes at the higher contraction speeds. The strength of knee extensors was lower in sedentary patients with diabetes at all velocities considered, with significantly lower values in D1 than that in D4 at 60°, 90°, and 120°·s(-1), whereas it was similar between TD and C subjects, especially at low contraction velocities. At the vastus lateralis, but not the biceps brachii, MFCV was lower in D1 and D4 as compared with TD and C subjects, showing similar values. CONCLUSIONS Muscle weakness in diabetes affects also the upper limb, although to a lower extent than the lower limb, is only partly related to motor nerve impairment, and is dependent on contraction velocity. Exercise training might counteract diabetes-induced alterations in muscle fiber contractile properties and MFCV.

Comparing Continuous and Intermittent Exercise: An “Isoeffort” and “Isotime” Approach

The present study proposes an alternative way of comparing performance and acute physiological responses to continuous exercise with those of intermittent exercise, ensuring similar between-protocol overall effort (isoeffort) and the same total duration of exercise (isotime). This approach was expected to overcome some drawbacks of traditional methods of comparison. Fourteen competitive cyclists (20±3 yrs) performed a preliminary incremental test and four experimental 30-min self-paced protocols, i.e. one continuous and three passive-recovery intermittent exercise protocols with different work-to-rest ratios (2 = 40∶20s, 1 = 30∶30s and 0.5 = 20∶40s). A “maximal session effort” prescription was adopted for this experimental design. As expected, a robust perceived exertion template was observed irrespective of exercise protocol. Similar between-protocol pacing strategies further support the use of the proposed approach in competitive cyclists. Total work, oxygen uptake and heart rate mean values were significantly higher (P<0.05) in the continuous compared to intermittent protocols, while lactate values were lower. Manipulating the work-to-rest ratio in intermittent exercise, total work, oxygen uptake and heart rate mean values decreased with the decrease in the work-to-rest ratio, while lactate values increased. Despite this complex physiological picture, all protocols showed similar ventilatory responses and a nearly perfect relationship between respiratory frequency and perceived exertion. In conclusion, our data indicate that overall effort and total duration of exercise are two critical parameters that should both be controlled when comparing continuous with intermittent exercise. On an isoeffort and isotime basis, the work-to-rest ratio manipulation affects physiological responses in a different way from what has been reported in literature with traditional methods of comparison. Finally, our data suggest that during intermittent exercise respiratory frequency reflects physiological strain better than oxygen uptake, heart rate and blood lactate.

Neuromuscular and Metabolic Responses to High-Intensity Intermittent Cycling Protocols With Different Work-to-Rest Ratios

PURPOSE To investigate the effects of work-to-rest-ratio manipulation on neuromuscular and metabolic responses during 2 high-intensity intermittent training (HIT) protocols to exhaustion. Since different exercise durations were expected, the authors hypothesized that the protocol registering a longer duration would have a more pronounced effect on neuromuscular responses, while the other would challenge the cardiopulmonary system more. METHODS Thirteen competitive cyclists (age 19 ± 2 y) performed a preliminary incremental test to identify their maximal power output and 2 intermittent protocols to exhaustion (40:20s and 30:30s) at a fixed work rate of 135%Pmax interspersed by passive recovery. Surface electromyographic (sEMG) parameters (including muscle-fiber conduction velocity), cardiopulmonary parameters, and blood lactate concentration [La-] were recorded. RESULTS Time to exhaustion and total work were significantly higher for the 30:30s (38 ± 13 min, 495 ± 161 kJ) than for the 40:20s (10 ± 3 min, 180 ± 51 kJ). No differences were found in sEMG parameters for the 2 protocols. Mean and peak values of VO2, heart rate, ventilatory parameters (except for the peak value of respiratory frequency), and [La-] were significantly higher in the 40:20s than in the 30:30s. CONCLUSIONS These results do not support the hypothesis that a longer time spent at high intensity has a more pronounced effect on neuromuscular responses, as no differences in EMG parameters were found in the 2 HIT protocols. Regarding metabolic responses, while the 40:20s led to maximal values of VO2, [La-], and ventilatory parameters within a few minutes, the 30:30s allowed maintenance of moderately high values for a considerably longer period, especially for [La-] and ventilatory parameters.

Volume-dependent effect of supervised exercise training on fatty liver and visceral adiposity index in subjects with type 2 diabetes The Italian Diabetes Exercise Study (IDES)

AIMS This study evaluated the effect of supervised exercise training on liver enzymes and two surrogate measures of non-alcoholic fatty liver disease (NAFLD) in subjects with type 2 diabetes. METHODS Sedentary patients from 22 outpatient diabetes clinics were randomized by center, age and treatment to twice-a-week supervised aerobic and resistance training plus structured exercise counseling (exercise group, EXE; n=303) versus counseling alone (control group, CON; n=303) for 12 months. EXE participants were further randomized to low-to-moderate (n=142) or moderate-to-high (n=161) intensity training of equal energy cost. Baseline and end-of-study levels of liver enzymes, fatty liver index (FLI) and visceral adiposity index (VAI) were obtained. RESULTS Enzyme levels did not change, whereas FLI and VAI decreased significantly in EXE, but not CON participants. Physical activity (PA) volume was an independent predictor of both FLI and VAI reductions, the extent of which increased from the 1st to the 4th quintile of PA volume and baseline to end-of-study changes in fitness parameters. Differences in the effect of LI versus HI training were negligible. CONCLUSIONS Data from this large cohort of subjects with type 2 diabetes indicate that FLI and VAI decrease with supervised training in a volume-dependent manner.

Older Age Is Associated with Lower Optimal Vibration Frequency in Lower-Limb Muscles During Whole-Body Vibration

ObjectiveThe aim of this study was to compare the optimal vibration frequency (OVF), which corresponds to maximal electromyographic muscle response during whole-body vibration, between young, middle-aged, and older women in four muscles of the lower-limbs. DesignOVF was measured as the frequency corresponding to maximal root mean square of the surface electromyogram (RMSmax) during a continuous incremental protocol, with a succession of vibration frequencies from 20 to 55 Hz (A = 2 mm), on the vastus lateralis, vastus medialis, rectus femoris, and gastrocnemius lateralis muscles of the dominant lower-limb. Seventy-eight women were divided into three age groups, that is, young, 21.6 ± 2.4 yrs; middle aged, 43.0 ± 5.2 yrs; and older, 74.2 ± 6.0 yrs. ResultsOVF in the vastus medialis was lower in the older women than in the middle-aged and young women, whereas OVF in the vastus lateralis was lower in the older than in the young women. There were no differences in OVF between muscles within each group. RMSmax was higher in the older than in the young women in all muscles. ConclusionsAge range should be taken into consideration when determining OVF because it decreases with age. Properly individualizing the vibration protocol might greatly influence neuromuscular effects of vibration training.

Effect of a Behavioral Intervention Strategy for Adoption and Maintenance of a Physically Active Lifestyle: The Italian Diabetes and Exercise Study (IDES) 2: A Randomized Controlled Trial

OBJECTIVE Adherence to physical activity (PA) recommendations is hampered by the lack of effective strategies to promote behavior change. The Italian Diabetes and Exercise Study 2 (IDES_2) is a randomized controlled trial evaluating a novel behavioral intervention strategy for increasing PA and decreasing sedentary time (SED-time) in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS The study randomized 300 physically inactive and sedentary patients with type 2 diabetes 1:1 to receive theoretical and practical counseling once yearly for 3 years (intervention group [INT]) or standard care (control group [CON]). Here, we report the 4-month effects on objectively (accelerometer) measured daily light-intensity PA (LPA), moderate-to-vigorous–intensity PA (MVPA), and SED-time, and cardiovascular risk factors. RESULTS LPA and MVPA both increased, and SED-time decreased in both groups, although changes were significantly more marked in INT participants (approximately twofold for LPA and SED-time and approximately sixfold for MVPA). A significant reduction in HbA1c was observed only in INT subjects. An increase in LPA >0.92 h · day−1 and in MVPA >7.33 min · day−1 and a decrease in SED-time >1.05 h · day−1 were associated with an average decrease in HbA1c of ∼1% and also with significant improvements in fasting glucose, body weight, waist circumference, and hs-CRP. Changes in PA and SED-time were independent predictors of improvements in HbA1c. CONCLUSIONS This behavioral intervention is effective in the short term for increasing LPA and MVPA and reducing SED-time. Significant improvements in cardiometabolic risk profiles were observed in subjects experiencing the most pronounced changes in PA and SED-time, even if below the recommended level.

Individual Optimal Frequency in Whole-Body Vibration: Effect of Protocol, Joint Angle, and Fatiguing Exercise

Abstract Carlucci, F, Felici, F, Piccinini, A, Haxhi, J, and Sacchetti, M. Individual optimal frequency in whole-body vibration: effect of protocol, joint angle, and fatiguing exercise. J Strength Cond Res 30(12): 3503–3511, 2016—Recent studies have shown the importance of individualizing the vibration intervention to produce greater effects on the neuromuscular system in less time. The purpose of this study was to assess the individual optimal vibration frequency (OVF) corresponding to the highest muscle activation (RMSmax) during vibration at different frequencies, comparing different protocols. Twenty-nine university students underwent 3 continuous (C) and 2 random (R) different vibrating protocols, maintaining a squat position on a vibration platform. The C protocol lasted 50 seconds and involved the succession of ascending frequencies from 20 to 55 Hz, every 5 seconds. The same protocol was performed twice, having the knee angle at 120° (C) and 90° (C90), to assess the effect of joint angle and after a fatiguing squatting exercise (CF) to evaluate the influence of fatigue on OVF assessment. In the random protocols, vibration time was 20 seconds with a 2-minute (R2) and a 4-minute (R4) pauses between tested frequencies. Muscle activation and OVF values did not differ significantly in the C, R2, and R4 protocols. RMSmax was higher in C90 (p < 0.001) and in CF (p = 0.04) compared with the C protocol. Joint angle and fatiguing exercise had no effect on OVF. In conclusion, the shorter C protocol produced similar myoelectrical activity in the R2 and the R4 protocols, and therefore, it could be equally valid in identifying the OVF with considerable time efficiency. Knee joint angle and fatiguing exercise had an effect on surface electromyography response during vibration but did not affect OVF identification significantly.

Extracorporeal Shockwave Therapy Improves Functional Outcomes of Adhesive Capsulitis of the Shoulder in Patients With Diabetes

Adhesive capsulitis of the shoulder (ACS) is the most prevalent musculoskeletal disorder of the upper extremity (1,2) among people with diabetes. ACS is characterized by intense shoulder pain with progressive limitation of joint mobility and functional disability, negative impact on the quality of life, and increased health care costs (3). In the population without diabetes, treatment options include supervised physical therapy, oral or intra-articular steroid injections, extracorporeal shockwave therapy (ESWT), and arthroscopic capsular release (4). Oral or intra-articular steroids lead to rapid pain relief and improved range of motion (ROM), although benefits from steroids may not be maintained beyond 6 weeks in patients with diabetes (5). In addition, steroids can significantly increase glucose levels, thus affecting glycemic control in patients with diabetes. Therefore , it would be preferable to avoid steroids and opt for alternative therapies in these individuals. In …