[Show abstract][Hide abstract] ABSTRACT: IN BRIEF Traditionally, aerobic training has been a central focus of exercise promotion for diabetes management. However, people with diabetes have much to gain from other forms of exercise. This article reviews the evidence and recommendations on resistance, balance, and flexibility training, as well as other, less traditional, forms of exercise such as yoga and Tai Chi.
[Show abstract][Hide abstract] ABSTRACT: Aims
For older adults with type 2 diabetes (T2DM), declines in balance and walking ability are risk factors for falls, and peripheral neuropathy magnifies this risk. Exercise training may improve balance, gait and reduce the risk of falling. This study investigated the effects of 12 weeks of aerobic exercise training on walking, balance, reaction time and falls risk metrics in older T2DM individuals with/without peripheral neuropathy.
Adults with T2DM, 21 without (DM; age 58.7 ± 1.7 yrs) and 16 with neuropathy (DM-PN; age 58.9 ± 1.9 yrs), engaged in either moderate or intense supervised exercise training thrice-weekly for 12 weeks. Pre/post-training assessments included falls risk (using the physiological profile assessment), standing balance, walking ability and hand/foot simple reaction time.
Pre-training, the DM-PN group had higher falls risk, slower (hand) reaction times (232 vs.219 ms), walked at a slower speed (108 vs. 113 cm/s) with shorter strides compared to the DM group. Following training, improvements in hand/foot reaction times and faster walking speed were seen for both groups.
While falls risk was not significantly reduced, the observed changes in gait, reaction time and balance metrics suggest that aerobic exercise of varying intensities is beneficial for improving dynamic postural control in older T2DM adults with/without neuropathy.
Journal of Diabetes and its Complications 09/2014; 28(5). DOI:10.1016/j.jdiacomp.2014.04.007 · 1.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abstract Background: Type 2 diabetes (T2D) is associated with autonomic nervous system damage resulting in reduced heart rate variability (HRV). Limited evidence suggests yogic breathing exercises may improve indices of HRV. Purpose: The purpose of this study was to evaluate the effect of two commonly used yogic breathing exercises on HRV in T2D versus an age-matched, normoglycemic (CON) population. Methods: Twelve (12) subjects with T2D (7 female, 5 male; 54.9±7.4 years) and 14 CON subjects (12 female, 2 male; 54.7±6.8 years) participated in a breathing protocol consisting of two 10-min bouts of randomly assigned uni-nostril breathing (UNB). UNB bouts were preceded and followed by 5-min periods of dual-nostril paced breathing (PB). HRV was measured by standard deviation of normal-to-normal consecutive heartbeats (SDNN), square root of the mean squared differences in successive normal heartbeats (RMSSD), and total spectral power (TP). All data (except instantaneous heart rate) were log transformed to improve normality. Within-group comparisons were analyzed using analysis of variance with repeated measures, whereas between-group comparisons were analyzed using independent-samples t-test. Results: Between-groups comparisons revealed significant reductions in all measures of HRV at nearly all time points in T2D compared to CON. Within-group comparison demonstrated no significant effect of UNB or PB on HRV in CON. In the T2D group, however, left UNB significantly reduced mean HR (-1.2 bpm, p<0.05) as well as TP (p<0.05). Conclusions: In summary, neither UNB nor PB had an impact upon HRV in a healthy older population and had a minimal impact in T2D.
Journal of alternative and complementary medicine (New York, N.Y.) 07/2014; 20(8). DOI:10.1089/acm.2013.0280 · 1.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives
To compare the impact of walking with a recreational activity on postprandial glycemia, heart rate variability, and mood state following the dinner meal.
Participants with type 2 diabetes (T2D) participated in 3 trials on different days in random order after ingestion of a standardized dinner meal (300 ± 6 kcals).
University clinical testing laboratory.
Twelve participants (9 female, 3 male; 58.7 ± 2.4 years) with uncomplicated T2D not taking insulin or beta-blocker medications.
Thirty minutes of self-paced walking on a treadmill (TM), 30 minutes of table tennis played continuously against the iPong robot (TT), and 30 minutes of rest (CON) undertaken 30 minutes after the start of ingestion of the same dinner meal on three occasions within a week.
Blood glucose was measured at 30-minute intervals through 180 minutes starting immediately prior to the dinner meal. Profile of Mood States was completed before and immediately following exercise or rest. Sympathovagal balance (heart rate variability) was measured prior to eating and 30 minutes after trial completion.
Compared with TT or CON, TM resulted in significantly lower postprandial blood glucose (P < .05), as well as a greater quantity of physical activity than TT (+72%) or rest (+91%; P < .01). Mean heart rate during TM was significantly greater than during TT (+25.9 beats per minute; P < .01). However, neither mood state nor HRV were significantly different among trials.
Thirty minutes of self-paced walking following the dinner meal may be more effective at lowering postprandial glycemia in T2D than a similar duration of table tennis played continuously against a robot.
Journal of the American Medical Directors Association 04/2014; 15(4). DOI:10.1016/j.jamda.2013.11.026 · 4.78 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Military personnel engage in strenuous physical activity and load carriage. This study evaluated the role of body mass and of added mass on aerobic performance (uphill treadmill exercise) and pulmonary function. Performance on a traditional unloaded run test (4.8 km) was compared with performance on loaded tasks. Subjects performed an outdoor 4.8-km run and four maximal treadmill tests wearing loads of 0, 10, 20 and 30 kg. Subjects' pulmonary function (forced expired volume in 1 second, FEV1; forced vital capacity, FVC; maximal voluntary ventilation, MVV) was tested with each load and peak values of heart rate (HR), oxygen consumption (VO2), ventilation (VE), and respiratory exchange ratio (RER) were measured during each treadmill test. Performance on the 4.8-km run was correlated with treadmill performance, measured as time to exhaustion (TTE), with the strength of the correlation decreasing with load (r = 0.87 for 0 kg to 0.76 for 30 kg). Body mass was not correlated with TTE, other than among men with the 30-kg load (r = 0.48). During treadmill exercise, all peak responses other than RER decreased with load. Pulmonary function measures (FEV1, FVC and MVV) decreased with load. Body mass was poorly correlated with treadmill performance, but added mass decreased performance. The decreased performance may be due in part to decreased pulmonary function. Unloaded 4.8-km run performance was correlated to unloaded uphill treadmill performance, but less so as load increased. Therefore, traditional run tests may not be an effective means of evaluating aerobic performance for military field operations.
The Journal of Strength and Conditioning Research 02/2014; 29(4):882-888. DOI:10.1519/JSC.0000000000000408 · 1.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Both peripheral and autonomic neuropathies are characterized by a progressive loss of nerve fiber function. Most peripheral neuropathy affects the extremities, particularly the lower legs and the feet, but also the hands, whereas damage to the autonomic nervous system may lead to imbalances between the sympathetic and parasympathetic nerve fibers that innervate the heart and blood vessels, as well as abnormalities in heart rate control and vascular dynamics. To prescribe or engage in exercise that is both safe and effective, health care providers and patients with diabetes mellitus need to increase their understanding of the pathophysiological nature of neuropathies and the physical activity hurdles that may arise from the presence of a neuropathy. With proper care and preventative measures, patients with diabetes mellitus that experience either type of neuropathy can benefit from regular participation in mild to moderate aerobic, resistance, and balance activities, assuming they take any potential alterations into account to ensure that exercise is safe and effective.
The Physician and sportsmedicine 02/2014; 42(1):15-23. DOI:10.3810/psm.2014.02.2043 · 1.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Gestational diabetes mellitus (GDM) is the most prevalent metabolic disorder during pregnancy. Women diagnosed with GDM have a substantially greater risk of developing type 2 diabetes within 5-10 years after delivery, and the risk is increased by excess body weight. Uncontrolled hyperglycemia during pregnancy is potentially harmful to both mother and fetus, resulting in a greater need for Caesarian-section deliveries, delivery of larger infants with more excess body fat, a greater risk of infant death and stillbirth, and an elevated risk of infant hypoglycemia immediately after birth. Fortunately, engaging in physical activity prior to and during pregnancy may lower the risk of developing GDM. Pregnant women should also be advised how to safely increase their physical activity during pregnancy and the postpartum period. An initial approach to becoming more physically active can simply be to encourage women to incorporate more unstructured physical activity into daily living, both before and during pregnancy. Giving women an appropriate exercise prescription can encourage them to participate in physical activity safely and effectively throughout pregnancy to prevent and/or manage GDM. Engaging in 30 min of moderate intensity physical activity on most, if not all, days of the week has been adopted as a recommendation for all pregnant women.
[Show abstract][Hide abstract] ABSTRACT: Our purpose was to develop and test a predictive model of the acute glucose response to exercise in individuals with type 2 diabetes.Design and Methods: Data from three previous exercise studies (56 subjects, 488 exercise sessions) were combined and used as a development dataset. A mixed-effects Least Absolute Shrinkage Selection Operator (LASSO) was used to select predictors among 12 potential predictors. Tests of the relative importance of each predictor were conducted using the Lindemann Merenda and Gold (LMG) algorithm. Model structure was tested using likelihood ratio tests. Model accuracy in the development dataset was assessed by leave-one-out cross-validation.Prospectively captured data (47 individuals, 436 sessions) was used as a test dataset. Model accuracy was calculated as the percentage of predictions within measurement error. Overall model utility was assessed as the number of subjects with <=1 model error after the third exercise session. Model accuracy across individuals was assessed graphically. In a post-hoc analysis, a mixed-effects logistic regression tested the association of individuals' attributes with model error.
Minutes since eating, a non-linear transformation of minutes since eating, post-prandial state, hemoglobin A1c, sulfonylurea status, age, and exercise session number were identified as novel predictors. Minutes since eating, its transformations, and hemoglobin A1c combined to account for 19.6% of the variance in glucose response. Sulfonylurea status, age, and exercise session each accounted for <1.0% of the variance.In the development dataset, a model with random slopes for pre-exercise glucose improved fit over a model with random intercepts only (likelihood ratio 34.5, p < 0.001). Cross-validated model accuracy was 83.3%.In the test dataset, overall accuracy was 80.2%. The model was more accurate in pre-prandial than postprandial exercise (83.6% vs. 74.5% accuracy respectively). 31/47 subjects had <=1 model error after the third exercise session. Model error varied across individuals and was weakly associated with within-subject variability in pre-exercise glucose (Odds ratio 1.49, 95% Confidence interval 1.23-1.75).
The preliminary development and test of a predictive model of acute glucose response to exercise is presented. Further work to improve this model is discussed.
[Show abstract][Hide abstract] ABSTRACT: Individuals who are currently sedentary, unfit, or overweight can benefit metabolically from simply taking breaks from sitting. Since avoidance of sedentary behavior appears to have a large impact on glycemic management, all individuals with type 2 diabetes should be encouraged to minimally engage in greater daily movement to better manage their diabetes and body weight. In addition, engaging in physical activity of any intensity (including low-intensity ones) likely positively impacts insulin action and blood glucose control acutely. Moreover, as long as total caloric expenditure during exercise is matched (i.e., total exercise dose), daily exercise may be done every other day instead with the same glycemic results, although at least 150 min of weekly physical activity is recommended. Both aerobic and resistance training are important for individuals with diabetes, and ideally a program that combines the two types of training should be undertaken to achieve maximal glycemic and other benefits. Once individuals have successfully implemented more daily movement into their lifestyle, they will be more likely to participate in structured forms of physical activity to gain additional benefits. All clinicians working with individuals with either type 2 diabetes or prediabetes should consider incorporating these suggestions into care plans to improve their patients' glycemic management.
Frontiers in Endocrinology 05/2012; 3:70. DOI:10.3389/fendo.2012.00070
[Show abstract][Hide abstract] ABSTRACT: For older individuals with diabetes, any decline in balance control can be especially problematic since it is often a precursor to an increased risk of falling. This study was designed to evaluate differences in postural motion dynamics and falls risk for older individuals with type 2 diabetes (T2DM) classified as fallers/non-fallers and, to assess what impact exercise has on balance and falls risk. The results demonstrated that the risk of falling is greater for those older individuals with multiple risk factors including diabetes and a previous falls history. The postural motion features of the high-risk individuals (T2DM-fallers) were also different, being characterized by increased variability and complexity, increased AP-ML coupling, less overall COP motion and increased velocity. One suggestion is that these individuals evoked a stiffening strategy during the more challenging postural tasks. Following training, a decline in falls risk was observed for all groups, with this effect being most pronounced for the T2DM-fallers. Interestingly, the COP motion of this group became more similar to controls, exhibiting decreased complexity and variability, and decreased velocity. The reciprocal changes in COP complexity support the broader view that age/disease-related changes in physiological complexity are bi-directional. Overall, these results show that, even for older T2DM individuals at greater risk of falling, targeted interventions can positively enhance their postural dynamics. Further, the finding that the pattern of postural motion variability and complexity was altered highlights that a decline in physiological complexity may not always be negatively associated with aging and/or disease.
[Show abstract][Hide abstract] ABSTRACT: An increasing prevalence of obesity and sedentary behavior has strongly contributed to the epidemic of type 2 diabetes mellitus. Although regular exercise improves glycemic control and is associated with reduced morbidity and mortality, many physicians fail to prescribe it. This article highlights the recommended types and quantities of physical activities that can (and should) be undertaken by individuals with type 2 diabetes, along with precautions required to maximize the safety of exercise in those using various medications and in the presence of diabetes-related complications. This article assesses the need for pre-exercise stress testing, reviews the latest exercise prescription recommendations for individuals with type 2 diabetes, and recommends strategies to assist individuals in adopting and maintaining an active lifestyle.
The Physician and sportsmedicine 05/2011; 39(2):13-26. DOI:10.3810/psm.2011.05.1909 · 1.49 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although physical activity (PA) is a key element in the prevention and management of type 2 diabetes, many with this chronic disease do not become or remain regularly active. High-quality studies establishing the importance of exercise and fitness in diabetes were lacking until recently, but it is now well established that participation in regular PA improves blood glucose control and can prevent or delay type 2 diabetes, along with positively affecting lipids, blood pressure, cardiovascular events, mortality, and quality of life. Structured interventions combining PA and modest weight loss have been shown to lower type 2 diabetes risk by up to 58% in high-risk populations. Most benefits of PA on diabetes management are realized through acute and chronic improvements in insulin action, accomplished with both aerobic and resistance training. The benefits of physical training are discussed, along with recommendations for varying activities, PA-associated blood glucose management, diabetes prevention, gestational diabetes mellitus, and safe and effective practices for PA with diabetes-related complications.
Diabetes care 12/2010; 33(12):e147-67. DOI:10.2337/dc10-9990 · 8.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It is well known that a number of locally released vasodilatory and vasoconstrictive compounds can affect skin perfusion. This study investigated the effects of aerobic training on the contribution of nitric oxide (NO), prostaglandins (PG), and endothelial-derived hyperpolarizing factor (EDHF) in stimulated dorsal foot skin perfusion in individuals with type 2 diabetes (T2DM). Ten previously sedentary, older individuals with T2DM (57.0 ± 3.1 years) and nine sedentary controls (53.5 ± 3.2 years) were tested before and after undertaking six months of moderate aerobic training three times weekly in a supervised setting. All subjects underwent measurement of baseline (32°C) and heat-stimulated (40°C and 44°C) dorsal foot skin perfusion starting one hour after ingestion of a single, oral 325 mg dose of aspirin, a known inhibitor of PG synthesis. Before aspirin ingestion, a subcutaneous microdialysis probe was inserted into each foot dorsum to administer either saline (PG pathway only blocked by aspirin in the left foot) or L-NAME (N(G)-nitro-l-arginine methyl ester; thereby inhibiting both PG and NO pathways in the right foot). Normative data collected previously on subjects undergoing saline administration via microdialysis without aspirin ingestion served as a control group. Significantly lower responsiveness of maximal perfusion was found with the EDHF pathway alone unblocked compared with NO and EDHF unblocked after training. Maximal suppression attributable directly to NO, PG, and EDHF was not significantly different when examined by subject group and training status. However, contributions of NO, PG, and EDHF to maximal perfusion were significantly increased, decreased, and unchanged by aerobic training, respectively, with diabetic and control subjects combined due to nonsignificant differences between groups. Improvements in maximally stimulated dorsal foot skin perfusion resulting from six months of aerobic training appear to have primarily an NO basis, with lesser contributions from PG following training, regardless of diabetes status.
Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy 08/2010; 3:275-280.