Type 2 diabetes is a metabolic disease marked by an abnormally high level of glucose (sugar) in the blood. Type 2 diabetes is now reaching an epidemic level with more than 30 million adults in the United States afflicted and 1.5 million new cases documented every year. Type 2 diabetes is linked with obesity, heart disease, hypertension, and liver disease, and individuals with type 2 diabetes are at an increased risk for heart failure, stroke, blindness, kidney failure, and amputation. According to the Centers for Disease Control and Prevention, more than $245 billion was spent in the United States in 2012 on medical expenses related to diabetes and despite that, nearly a quarter of a million Americans are losing their lives due to this disease each year. Indeed, type 2 diabetes is one of the leading causes of death in the United States and worldwide; its prevalence has almost doubled in the last 35 years, from 4.7% of the total population in 1980 to 8.5% in 2014. Consequently, more than 400 million people are at high risk for severe health problems and complications, poor quality of life, and early death. Research such as the Diabetes Prevention Program (DPP), the Finnish Diabetes Prevention Study (DPS), the Vesterbotten Intervention Program (VIP), and the Diabetes Prevention Program Outcome Study (DPPOS) suggests that type 2 diabetes can be delayed, and even prevented, with a lifestyle behavioral modification program that includes healthy eating and/or exercise. Therefore, focus has been shifted from management to prevention. An early manifestation of dysfunction in the progression of type 2 diabetes is insulin resistance, a metabolic impairment associated with obesity. Indeed, it is estimated that ~90% of people with type 2 diabetes also are obese. The link between insulin resistance and obesity is well-established; however, the mechanistic basis(es) underpinning this link is/are still debated with multiple candidate molecules, systems, and pathways potentially involved. One theory that has gained traction in recent years suggests that type 2 diabetes, and the insulin-resistant state that predates it, are rooted in dysfunctional lipid metabolism (i.e., a reduced capacity to use lipid for energy production in circumstances where lipid would be preferred, such as in the basal fasting condition, after a high-fat meal, and during light- and moderate-intensity exercise). However, there are conflicting findings regarding the degree to which the ability to oxidize lipid during these circumstances is compromised for individuals with the overweight/obesity that is associated with the disease progression. The reason(s) for this ambiguity is/are unclear but might have to do with a number of factors that were poorly controlled when substrate selectivity (i.e., lipid vs. carbohydrate oxidation rates) were compared between normal-weight individuals and those with the overweight/obese condition. These include: (a) acute energy balance and macronutrient composition of the diet; (b) the intensity and duration of the exercise bout; and (c) subject characteristics including the amount of muscle tissue they possess, their cardiorespiratory fitness level, and, perhaps most importantly, their insulin-sensitivity state. The purpose of this dissertational work is to: (a) help to resolve this ambiguity by identifying the degree to which conflicting results that have been reported might be explained by factors that were left unaccounted for and/or inadequately controlled in previous research; and (b) compare substrate selectivity in normal-weight individuals and those with the overweight/obesity condition during a physiologically-equivalent exercise challenge with the aforementioned factors rigidly controlled.

The purpose of this study was to determine the validity of the Ebbeling one-stage submaximal treadmill protocol to estimate maximal oxygen uptake in overweight males and females. Forty-five male and females (36.5±10.9 years; 170.2±9.9 cm; 77.9±9.0 kg) were categorized into overweight groups using a BMI of 25-29.9 kg/m2. The subjects performed a submaximal protocol that consisted of one 4-minute stage with individualized speeds of 2.0-4.5 mph at 5% grade and subsequently performed a maximal exercise test. There were significant relationships between observed and estimated VO2max for males (r=.796), females (r=.426), and gender combined (r=.844). There was an underestimation in the estimation of VO2max in the present study when comparing males (10%), females (26%) and gender combined (17%) subjects. The results indicated that a body mass index between the values of 25-29.9 kg/m2 did create a difference in estimating VO2max in the present study when comparing that to Ebbeling et al. (1991).Ball State UniversityMuncie, IN 47306 / School of Physical Education

Thesis (M.S.)--James Madison University, 2009. / Includes bibliographical references.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

No description available.

The heart rate achieved with maximal upper limb exercise is quoted as being on average thirteen beats per minute lower than when performing maximal leg exercise. Many canoeists use heart rate monitors during training and seek advice on setting their heart rate training zones. Existing guidelines are based on lower limb-derived heart rates, which may not be appropriate. As canoeists use predominantly their upper limbs during canoeing, it was hypothesized that as their upper limbs are trained, they may achieve heart rates and oxygen consumption similar to those achieved with lower limb exercise. The purpose of this investigation was to compare the relationship between heart rate and oxygen consumption when exercising on either a kayak ergometer or treadmill. Fifteen volunteer canoeists, who compete regularly, were recruited by convenience, purposive sampling and randomly allocated to a V02max test using open circuit spirometry, on either a kayak ergometer or treadmill. They returned within 5 to 7 days for a V02max test on the other apparatus. Their heart rates were also measured during these activities. The heart rate oxygen consumption relationship for upper and lower limb exercise was then analysed. Maximum heart rate was on average only 6 beats per minute lower with upper limb exercise, with some subjects achieving the same or very similar HRmax; the median difference in heart rate maximum was only 4 beats per minute. Although the response of heart rate and oxygen consumption to kayaking and running was similar at any given workload, the heart rate on the kayak was about 8 beats per minute higher at any submaximal workload. V02max. on the kayak was lower than on the treadmill. At any metabolic equivalent, the tidal volume was lower on the kayak and there was a lower respiratory rate on the treadmill. At any tidal volume, the metabolic equivalent was lower on the kayak ergometer. The minute volume on the kayak was higher than on the treadmill, for all but the highest intensities of exercise. Using the leg heart rate max to determine the training zones, a slightly higher (negligible) percentage of arm V0max is achieved at any given percentage heart rate. Kayakers who train regularly, appear to be able to attain similar maximum heart rates with upper and lower limb exercise, but a lower V02max when exercising with their arms. The heart rate oxygen consumption response is the same for upper and lower body exercise; and a reduced HRmax and increased heart rate at any sub maximal workload do not appear to apply to canoeists. It is therefore concluded that heart rate training zones based on leg HRmax are suitable for kayak training. This study has helped distinguish the difference between the heart rates of the upper and lower limbs at any given oxygen consumption in canoeists. The benefits of performing this study have also been to provide better advice to canoeists on how to train using heart rate monitors. / Thesis (M.Med.Sc.)-University of Natal, Durban, 2003.

No description available.

Ground contact results in the generation of a heel-strike transient that propagates through the musculoskeletal system. The inability to attenuate the heel-strike-induced shock wave is a possible factor in the development of various gait pathologies and overuse-type injuries, such as knee osteoarthrosis, stress fractures, and low back pain. It is hypothesized that prolonged running will result in increased shock transmission at the tibia and sacroiliac joint during conditions of controlled velocity/stride mechanics. Subjects performed an extended running trial for 25-minutes at 75% HRReserve. EMG data of the vastus medialis, vastus lateralis, and tibialis anterior and accelerometer data from the tibial tuberosity and sacrum were recorded at one-minute intervals. Accelerometer data at the tibial tuberosity did show a significant increase during the run protocol. Linear regression of EMG frequency and tibial shock also demonstrated a significant relationship. An extended running protocol will lead to increases in tibia shock acceleration independent of stride mechanics. / School of Physical Education

The purpose of this study was to evaluate the intermodal reliability of perceptually-based exercise intensity among four machines: Treadmill (TM), Stationary cycle (CB), Body Trec elliptical arm/leg (BT), and AirDyne (AD). Nineteen subjects (8 male and 11 female; age 44 + 12 yrs) completed one GXT on each of the machines, following a mode-specific protocol. Subjects also completed two 15 minute production trials (PTs) on each machine at self-selected workrates corresponding to target RPEs of 11-12 (L) and 15-16 (H). In the PTs, workloads were self-adjusted through the first 5 minutes and then remained stable for the rest of the trial. Modes were randomly assigned, and subjects were blinded to the workload throughout each trial. Heart rate (HR) and oxygen uptake (V02) were obtained during the final 5 min. of each trial using a Polar HR monitor and Aerosport TEEM 100. Also, blood lactate (BLC) was sampled immediately following exercise at each intensity. Intermodal reliability was assessed using ANOVA, intraclass correlations (R), coefficients of variation (CV), and mean absolute differences for HR, V02, and BLC during the second PT. ANOVA revealed nointeraction for BLC at either the LOW or HIGH. Post -hoc analysis showed the TM and/or BT to produce significantly higher physiological responses at both intensity levels. At the L and H, intermodal Rs were: HR (.84/.88), VO2 (8/.77) and BLC (0.09/0.67). Significant intrasubject differences were observed at the L for HR (11-47bpm, VO2 (.04-1.46 L/min), and BLC (.29-12.94 mM/L). The H trials followed a very similar trend. Using a HR criteria of +2 beats/15 sec. to assess intrasubject reliability, 0% of the subjects were reliable at both the L and H. This data suggests that perceptually-based exercise across multiple modes is associated with significant intraindividual variability, and reliability is dependent upon the statistical design and physiological variable being used. In conclusion, it is recommended that extensive exercise testing be performed to ensure that individual participants can reliably use the RPE scale, prior to using an RPE value to prescribe the intensity of exercise. / School of Physical Education

Background: Whole-body vibration (WBV) has been proposed as a viable alternative, or adjuvant to exercise for power development in athletes. More recently individualized frequency (I-Freq) has been introduced with the notion that individuals may elicit a greater reflex response to different levels (Hz) of vibration. Purpose: The aim of the study was to evaluate acute WBV as a feasible intervention to increase power in trained cyclists. Additionally, to evaluate the efficacy of utilizing I-Freq as an alternative to 30Hz, a common frequency seen in the literature. Methods: Twelve highly-trained, competitive male cyclists (age= 29.9 yrs ± SD 10.0; body height=175.4 cm ± SD 7.8; body mass= 77.3 kg ± SD 13.9) free of musculoskeletal injury or pathology participated in the study. The Wingate test for anaerobic power was administered on three occasions following a control of no vibration, 30 Hz, and I-freq. Measures of peak power (PP), average power (AP) and rate of fatigue were recorded and compared to the vibratory conditions using separate RM-ANOVA’s. Results: PP, AP, and rate of fatigue were not significantly impacted by 30 Hz and I-Freq vibration interventions (p > 0.05). Conclusion: Acute WBV using the parameters of the present study may not have been practical to elicit an increase in power as potential changes in the highly trained population may have been muted as a function of training status. / School of Physical Education, Sport, and Exercise Science