The purpose of this study was to determine whether there is a difference in respiratory mechanics and gas exchange between polio survivors and healthy, age-matched controls during wakefulness and sleep. Polio survivors were divided into four groups. The first group included those who had evidence of respiratory muscle involvement originally (PRM) and the second group included those who had bulbar muscle involvement originally (PBM). The third and fourth groups had only limb involvement originally but were separated by absence (PSL) or presence of a scoliosis (PSS) at the time of their evaluation. Each subject completed baseline and one year follow-up measurements of lung volumes, diffusion, flow rates, respiratory muscle strength, central and peripheral chemoreflexes and arterial blood gases. Sleep measurements included a full respiratory polysomnographic study. Fifty polio survivors and 13 controls completed the study. The PRM and PSS groups had an elevated arterial carbon dioxide tension (PaCO2) (mean +/- SE 6.0 +/- 0.4 and 6.0 +/- 0.3 kPa, respectively), reduced vital capacity (2.8 +/- 0.3 and 2.9 +/- 0.3 l, respectively), reduced maximal inspiratory pressure (-5.9 +/- 0.7 and -5.4 +/- 0.8 kPa, respectively) and reduced maximal expiratory pressure (9.8 +/- 1.1 and 9.1 +/- 1.2 kPa, respectively), when compared with non-polio controls. During sleep PRM and PSS groups experienced a higher PaCO2 (6.5 +/- 0.5 and 6.7 +/- 0.4 kPa, respectively) and a lower arterial oxygen saturation (SaO2) (89 +/- 4 and 86 +/- 3%, respectively). There were no differences among groups for diffusion, flow rates and chemoreflexes. All other polio survivors showed essentially normal respiratory function.(ABSTRACT TRUNCATED AT 250 WORDS)

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Background Weight loss and improving cardiorespiratory fitness are key treatment outcomes for obese individuals with Obstructive Sleep Apnoea (OSA). We investigated the total energy expenditure and cardiorespiratory response to weight supported (cycling) and unsupported (walking) at two different intensities. Methods Individuals with treated OSA and a BMI >30 kg/m 2 performed an incremental cardiopulmonary exercise test on a cycle ergometer (ICE) and a treadmill (ITM) with expired gas analysis to determine the peak oxygen uptake (VO 2 pk). Participants completed two endurance tests on each modality matched at 80% and 60% of the highest VO 2 pk determined by the incremental tests. The cardiorespiratory responses were measured and total energy expenditure was estimated from the VO 2 .

IntroductionWe wish to investigate whether dynamic hyperinflation contributes to exercise intolerance in patients with severe asthma. It is unclear whether there is an influence by the exercise platform. To begin with, we explored whether performing serial inspiratory capacity (IC) manoeuvres is feasible during a maximal incremental treadmill test in patients with severe asthma.MethodPatients with severe asthma (step 4–5 of the British Thoracic Society guidelines), MRC dyspnoea grade ≥2, were recruited from physicians specialising in the care of patients with difficult-to-treat asthma at Glenfield Hospital, Leicester. Patients were excluded if they had both fixed airflow obstruction (FEV1/FVC <70%) and a smoking history of ≥10 pack years. All participants performed an incremental treadmill test to intolerance, with expiratory gas analysis, designed to produce a linear increase in peak oxygen uptake (VO2).1 Patients performed a practice resting inspiratory capacity manoeuvre and then subsequently at rest, during the warm up phase and every two minutes during exercise.Results18 participants (8 female, mean [SD] 49 [14] yrs, BMI 31 [7] kg/m2, FEV1/FVC 70 [13]%, 17% were ex-smokers) completed the treadmill test in a duration of 482 [120] s. Observations at peak exercise were: VO2 2.0 [0.4] L/min (100 [25]% predicted); ventilation 67 [18] L/min (87 [20]% maximum voluntary ventilation); heart rate 145 [17] beats/min (85 [9]% predicted); Borg Score for breathlessness 7 [2], perceived exertion 17 [3], 16 were predominantly limited by breathlessness. 115 IC manoeuvres were performed with only one datapoint missed due to an incomplete manoeuvre. Figure 1 shows the mean end expiratory and inspiratory lung volumes during exercise. Six patients had an inspiratory reserve volume of <500 mls.Abstract S100 Figure 1Inspiratory capacity during a maximal incremental treatmill test in patients with severe asthmaConclusionAssessment for dynamic hyperinflation with serial inspiratory capacity manoeuvres during a maximal incremental treadmill test is feasible in patients with severe asthma. The relationship among lung volumes, time and ventilation can be established from rest to peak exercise with minimal practice of the IC manoeuvre or interruption to the test in this patient population.Reference1 Porszasz J, Casaburi R, Somfay A, et al. Med Sci Sports Exerc. 2003;35: 1596–1603

IntroductionPulmonary Rehabilitation is recommended for patients with Idiopathic Pulmonary Fibrosis (IPF) although the magnitude of benefit appears less compared to those with other chronic lung diseases. Patients with IPF may not be able to sustain high-intensity training to induce physiological change due to a ventilatory limitation to exercise. One strategy to circumvent this in COPD has been to reduce the exercising muscle mass by cycling one leg at a time during the same exercise session. Randomised controlled trials have shown greater improvements in exercise capacity after training using one-legged cycling (OLC) compared to two-legged cycling (TLC).1,2 We, therefore, compared OLC to TLC responses during incremental and constant work rate (CWR) exercise in patients with IPF.MethodsPatients were recruited from a tertiary referral centre if they met the current NICE diagnostic criteria for IPF with a MRC dyspnoea grade ≥2. Exclusion criteria included a requirement for long-term oxygen therapy. Participants completed four Cardiopulmonary Exercise Tests (CPETs) to intolerance on a cycle ergometer with expired gas analysis. The tests were completed on separate days: 1) two-legged maximal incremental test (TLC-ICE); 2) one-legged maximal incremental test (OLC-ICE); 3) two-legged CWR (TLC-CWR) test at 70% peak power achieved on the TLC-ICE; 4) one-legged CWR (OLC-CWR) test at 35% TLC-ICE peak power.ResultsTwelve participants (11 male, mean [SD] 73 [8] yrs, BMI 30.6 [4.8] kg/m2, FVC% predicted 71.8 [20.3]%, resting SpO2 98 [1]%) completed all four CPETs demonstrating a ventilatory limitation to exercise (92 [14]% maximum voluntary ventilation [MVV]). Although the OLC-ICE peak oxygen uptake (peak VO­2) was significantly lower than the peak VO2 TLC-ICE (p < 0.001) the OLC: TLC was high at 0.85. The OLC-CWR was endured for more than twice the TLC-CWR (p < 0.001) at the same muscle-specific power leading to almost double the work being performed (Table 1).Abstract P134 Table 1A comparison between Two-Legged (TLC) vs. One Legged (OLC) Constant Work Rate (CWR) exercise testsPeak valuesTLC-CWROLC-CWRpDuration, min6.1 (3.7)22.7 (15.0)0.001Power, W68.5 (24.3)34.3 (12.2)<0.001Work, kJ26.7 (20.6)53.4 (48.3)0.02VE Peak, L/min70.0 (23.0)61.6 (28.1)0.03HR, beats/min118 (20)108 (20)0.04Borg Score, Dyspnoea *6 (2)5 (3)0.13Borg Score, Leg Effort *15(3)17 (4)0.02SpO2%87 (7)89 (6)0.03Mean SD,* = median IQR, SpO2 = oxygen saturation by pulse oximetry.ConclusionOLC at the same muscle-specific power compared to TLC enabled patients with IPF to achieve almost double the work in a simulated exercise training session. Future research should investigate OLC as a potentially efficacious aerobic training strategy for patients with IPF.References1 Bjorgen SJ. Eur J ApplPhysiol 2009;106:501–5072 Dolmage TE. Chest 2008;133:370–376