Bart Drinkard

Benefits of intensive treadmill exercise training on cardiorespiratory function and quality of life in patients with pulmonary hypertension.

BACKGROUND Pulmonary hypertension (PH) restricts the ability to engage in physical activity and decreases longevity. We examined the impact of aerobic exercise training on function and quality of life in patients with World Health Organization group 1 PH. METHODS Patients were randomized to a 10-week education only (EDU) or education/exercise combined (EXE) group. The exercise program consisted of 24-30 sessions of treadmill walking for 30-45 min per session at 70% to 80% of heart rate reserve. Outcome variables included changes in 6-min walk test (6MWT) distance, time to exercise intolerance, peak work rate (WR) from a cardiopulmonary treadmill test, and quality-of-life measures, including the Short Form Health Survey, version 2 (SF-36v2) and Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR). RESULTS Data are presented as mean SD. Twenty-three women (age, 54 11 years; BMI, 31 7 kg/m 2 ) were randomized to the EDU (n 5 13) or EXE (n 5 10) groups. Following 10 weeks of intervention, patients in the EXE group demonstrated an improvement in 6MWT distance (56 45 m; P 5 .002), increased time to exercise intolerance (1.9 1.3 min; P 5 .001), and peak WR (26 23 W; P 5 .004). Additionally, the EXE group scored significantly ( P , .050) better on six of the eight scales on SF-36v2, and fi ve of the six scales on CAMPHOR. In contrast, no significant improvement was observed for any of the outcome measures following EDU. No adverse events were noted in either group. CONCLUSION Ten weeks of brisk treadmill walking improved 6MWT distance, cardiorespiratory function, and patient-reported quality of life in female patients with group 1 PH.

Exploratory Analysis of the Relationships between Aerobic Capacity and Self-Reported Fatigue in Patients with Rheumatoid Arthritis, Polymyositis, and Chronic Fatigue Syndrome

To determine if self‐reported levels of physical activity and fatigue are related to peak oxygen uptake (VO2peak) and whether these relationships differ among the patient groups (rheumatoid arthritis [RA], polymyositis [PM], and chronic fatigue syndrome [CFS]).

Recruitment to a physical activity intervention study in women at increased risk of breast cancer

BackgroundPhysical activity is being studied as a breast cancer prevention strategy. Women at risk of breast cancer report interest in lifestyle modification, but recruitment to randomized physical activity intervention studies is challenging.MethodsWe conducted an analysis of recruitment techniques used for a prospective, randomized pilot study of physical activity in women at risk of breast cancer. We evaluated differences in proportion of eligible patients, enrolled patients, and successful patients identified by each individual recruitment method. The Fisher-Freeman-Halton test (an extension of Fishers exact test from 2 × 2 tables to general row by column tables) was used to compare the success of different recruitment strategies.ResultsWe received 352 inquiries from women interested in participating, of whom 171 (54%) were eligible. Ninety-nine women completed a baseline activity evaluation, and 58 (34% of eligible; 16% of total inquiries) were randomized. Recruitment methods fell into three broad categories: media techniques, direct contact with potential participants, and contacts with health care providers. Recruitment strategies differed significantly in their ability to identify eligible women (p = 0.01), and women who subsequently enrolled in the study (p = 0.02).ConclusionRecruitment techniques had varying success. Our data illustrate the challenges in recruiting to behavior modification studies, and provide useful information for tailoring future recruitment efforts for lifestyle intervention trials.Trial Registration No(s)CDR0000393790, NCI-04-C-0276, NCI-NAVY-B05-001

Cardiorespiratory function before and after aerobic exercise training in patients with interstitial lung disease.

PURPOSE: To characterize the cardiorespiratory response to exercise before and after aerobic exercise training in patients with interstitial lung disease. METHODS: We performed a clinical study, examining 13 patients (New York Heart Association/World Health Organization Functional class II or III) before and after 10 weeks of supervised treadmill exercise walking, at 70% to 80% of heart rate reserve, 30 to 45 minutes per session, 3 times a week. Outcome variables included measures of cardiorespiratory function during a treadmill cardiopulmonary exercise test, with additional near infrared spectroscopy measurements of peripheral oxygen extraction and bioimpedance cardiography measurements of cardiac output. Six-minute walk test distance was also measured. RESULTS: All subjects participated in at least 24 of their 30 scheduled exercise sessions with no significant adverse events. After training, the mean 6-minute walk test distance increased by 52 ± 48 m (P = .001), peak treadmill cardiopulmonary exercise test time increased by 163 ± 130 s (P = .001), and time to achieve gas exchange threshold increased by 145 ± 37 s (P < .001). Despite a negligible increase in peak o2 with no changes to cardiac output, the overall work rate/ o2 relationship was enhanced after training. Muscle O2 extraction increased by 16% (P = .049) after training. CONCLUSIONS: Clinically significant improvements in cardiorespiratory function were observed after aerobic exercise training in this group of subjects with interstitial lung disease. These improvements appear to have been mediated by increases in the peripheral extraction of O2 rather than changes in O2 delivery.

Oxygen uptake on-kinetics before and after aerobic exercise training in individuals with traumatic brain injury

Abstract Objective: The high prevalence of fatigue among persons with traumatic brain injury (TBI) may be related to poor cardiorespiratory fitness observed in this population. Oxygen uptake on-kinetics is a method of assessing cardiorespiratory fitness and may be used to examine performance fatigability (decline in performance during a given activity) in persons with TBI. Purpose: To examine the effect of aerobic exercise training on oxygen uptake on-kinetics during treadmill walking in individuals with TBI. Methods: Seven ambulatory adults with chronic non-penetrating TBI performed short moderate-intensity (3–6 metabolic equivalents) walking bouts on a treadmill, prior to and following an aerobic exercise training program (clinicaltrials.gov: NCT01294332). The 12-week training program consisted of vigorous-intensity exercise on a treadmill for 30 min, 3 times a week. Breath-by-breath pulmonary gas exchange was measured throughout the bouts, and oxygen uptake on-kinetics described the time taken to achieve a steady-state response. Results: Faster oxygen uptake on-kinetics was observed after exercise training, for both the absolute and relative intensity as pre-training. Conclusions: Faster oxygen uptake on-kinetics following aerobic exercise training suggests an attenuated decline in physical performance during a standardized walking bout and improved performance fatigability in these individuals with TBI. Implications for rehabilitation Severe fatigue is a common complaint among persons with traumatic brain injury (TBI). Oxygen uptake on-kinetics may be used as an objective physiological measure of performance fatigability in persons with TBI. Faster oxygen uptake on-kinetics following aerobic exercise training suggests improved performance fatigability in these individuals with TBI. Aerobic exercise training appeared beneficial for reducing performance fatigability and may be considered as part of the rehabilitative strategy for those living with TBI.