Interval exercise training in cystic fibrosis — Effects on exercise capacity in severely affected adults

Exercise and Airway Clearance Techniques in Cystic Fibrosis

Exercise and airway clearance techniques (ACTs) have been a cornerstone of treatment for people with cystic fibrosis (pwCF) for many decades. Exercise may confer both respiratory and nonrespiratory benefits for pwCF, with greater exercise capacity associated with improved survival. A wide variety of exercise interventions for pwCF have been investigated. ACTs may assist in reducing respiratory symptoms for pwCF and are currently recommended to be performed daily, with the types of ACTs used varying globally. While recommended components of care, both exercise and ACTs are time-intensive and maintaining adherence to the recommendations over the longer term can be challenging. It has been proposed that with advances in the therapeutic options for pwCF, a rationalization of the therapeutic regimen may be possible. We summarize the current evidence for the use of exercise and ACTs by pwCF, discuss the implications of the introduction of cystic fibrosis transmembrane conductance regulator modulators on both exercise and ACTs, and highlight areas for further research.

Effectiveness of Physical Exercise Interventions on Pulmonary Function and Physical Fitness in Children and Adults with Cystic Fibrosis: A Systematic Review with Meta-Analysis

Objective: Physical exercise is associated with several benefits in the treatment of cystic fibrosis (CF), associated with a reduction in patient mortality. The aim of this systematic review was to determine the effectiveness of exercise interventions on physical condition and lung function in children and adults with CF to establish the most appropriate type and dose of physical exercise used so far. Methods: The studies included were randomized controlled trials with physical exercise interventions performed with children or adults with CF, analyzing the effects on pulmonary function, cardiorespiratory capacity, and muscle strength. The variables analyzed in at least four studies in the same population (children or adults) with the same measuring test were included in the meta-analysis. Results:Pulmonary function: There were no changes in the forced expiratory volume 1 s, but mouth expiratory/inspiratory pressures were improved in some studies. Physical fitness: In children, the interventions did not manage to improve the VO2peak (SMD = 0.22; 95%CI: -0.25 to 0.68; p = 0.73) but improved muscle strength. In adults, physical exercise interventions based on high-intensity aerobic training showed positive results in the VO2peak, and in some muscle strength outcomes. Conclusions: Exercise interventions in children and adults with CF are effective in improving muscle strength, cardiovascular capacity, and respiratory muscle function. However, they do not achieve improvements in lung function. The most effective programs are those using strength training or cardiovascular high-intensity interval training, although to date there have been few such interventions.

Effects of a Long-Term Monitored Exercise Program on Aerobic Fitness in a Small Group of Children with Cystic Fibrosis

Background: The aim of this study was to investigate the effects of a monitored exercise program on aerobic fitness in children with cystic fibrosis (CF). Methods: Six children (2f/4m) with ages ranging from 6 to 14 years (11.3 ± 3.3 years.) and a mean ppFEV1 102.5 ± 13.5% pred. participated in the partially monitored 12-month exercise program. VO2peak and Wpeak were used as parameters of aerobic fitness. Incremental Cardio-Pulmonary Exercise Tests (CPETs) were performed before the program began (T1), after 6 months (T3) of monitoring, and after a further 6 months (T4) without monitoring. Habitual physical activity (HPA) was assessed with accelerometry. Results: The values of VO2peak and Wpeak improved slightly from T1 to T3 (p > 0.05), without a further increase after monitoring was stopped (T4). However, the VO2peak and Wpeak values were higher after monitoring was stopped compared to at T1. The exercise program with and without monitoring (p > 0.05) had no or only a slight effect on the FEV1 values, steps/day, and the intensity of HPA. Conclusions: Monitoring seems to facilitate the achievement of beneficial effects on physical fitness in CF children. For that reason, continuous individual exercise monitoring programs that involve close contact with an exercise therapist should be provided to maintain long-term motivation and participation in physical activities and sport activities during leisure time.

The effectiveness of exercise interventions to increase physical activity in Cystic Fibrosis: A systematic review

Physical activity (PA) and exercise have numerous benefits in Cystic Fibrosis (CF) including improved lung function, exercise capacity and quality of life. Despite these benefits, the effectiveness of interventions to promote PA in this population are still largely unknown. The objective of this review was to synthesise existing research and determine whether exercise interventions are effective in promoting PA in people with CF. Using the PRISMA guidelines, a comprehensive search was conducted. Fifteen studies (463 participants) met the inclusion criteria. Eleven studies demonstrated improvements in PA in both short- and long-term interventions. However, the interventions were variable across the included studies, with a large inconsistency in PA assessment tools used. Aerobic training and activity counselling were the two elements identified in this review which most consistently improved PA. Future research should consider larger sample sizes and the use of accurate instruments to assess and track PA levels longitudinally.

Rethinking physical exercise training in the modern era of cystic fibrosis: A step towards optimising short-term efficacy and long-term engagement

Exercise is considered as an important component of the package of care delivered to people with cystic fibrosis (pwCF). However, despite the well-known short-term physiological and psychological benefits, training effects are heterogenous and the transfer of structured exercise programmes to the daily life of pwCF is challenging. Training concepts and strategies developed over the last decades must be adapted to consider the aging population of pwCF with associated comorbidities, and also a new generation of young pwCF that are healthier than ever. In the present review we propose a new framework for optimising the choice among available exercise training procedures and we provide a theoretical and scientifically justified rationale for considering and testing new exercise training modalities. We propose a multidisciplinary approach, considering various physiological, psychological and logistical factors, with the aim to increase effects of exercise training and build positive long-term exercise behaviour.

Health-Related and Motor Performance-Related Fitness and Physical Activity Among Youth With Cystic Fibrosis

Little is known about motor competence and the longitudinal development of motor performance among youth with cystic fibrosis (CF). In this study, we assessed aspects of motor performance in different age groups of young patients with CF and compared them with a healthy reference group of same aged children. We also examined the development of motor performance among different age groups of these children with CF, using The Deutscher Motorik Test (DMT) to assess attributes of health-related and motor performance-related fitness. We used an incremental ergometer cycle test to determine maximal exercise capacity (expressed as peak workload). We evaluated and recorded habitual physical activity (PA) as measured by the number of steps per day and the time spent in different PA intensities (expressed in metabolic equivalents). In total, 31 children and adolescents with CF agreed to participate (13 girls,18 boys) aged 6-17 years (M = 11.3, SD =3.3 years); they had a mean one second forced expiratory volume (expressed as a percentage of predicted value [% pred]) of 87.2% (SD = 22.3%). We found their values of health-related and motor performance-related fitness to be significantly lower (p < 0.05) than those of their healthy peer participants. In contrast to the reference group, participants with CF up to 14 years of age showed a linear improvement in these values and in their PA, followed by a plateau or even a nonsignificant decrease after age 14. These findings have important implications for the development and prescription of exercise programs for children with CF. Besides aerobic and strength exercises, we recommend that neuromuscular training be integrated into exercise programs to improve the coordinative abilities of youth with CF. More attention should be paid to vulnerable older adolescents to ensure their long-term motivation to maintain exercise participation.

Pulmonary rehabilitation for cystic fibrosis: A narrative review of current literature

Pulmonary rehabilitation is a key component in cystic fibrosis care.  This review summarizes the recent evidence in the area of pulmonary rehabilitation for cystic fibrosis in the form of questions and answers regarding interventions, indications, benefits and risks of pulmonary rehabilitation. Pulmonary rehabilitation includes airway clearance techniques, exercise training, education and behaviour change and can improve patients' exercise capacity, muscle strength, quality of life and nutritional status. Airway clearance techniques have beneficial effects for clearing mucous. Over the past years, evidence for the beneficial effects of exercise training on exercise capacity and overall lung health is growing. In cystic fibrosis, multiple factors result in reduced exercise capacity. All modalities of pulmonary rehabilitation should be offered to patients with cystic fibrosis, as the benefits in most cases outweigh the risks, though the optimal regimens need to be yet defined.

Interval versus constant-load exercise training in adults with Cystic Fibrosis

BACKGROUND

The efficacy of interval exercise (IE) compared to constant-load exercise (CLE) training remains unsettled in adults with Cystic Fibrosis (CF).

METHODS

Twenty-four adults with CF were randomised to 30-min IE (100 % peak work capacity (WRpeak) for 30-s alternated with 40 % WRpeak for 30-s; n = 12) or 30-min CLE (70 % WRpeak; n = 12) training, 3 times weekly, for 12 weeks. Isometric quadriceps muscle strength was assessed using a strain gauge Myometer.

RESULTS

The magnitude of improvement in quadriceps muscle strength was greater (p = 0.037) in the IE (by 32 ± 13 Nm) compared to the CLE (by 23 ± 12 Nm) groups. Maximum inspiratory and expiratory mouth pressures were significantly improved only in the IE group (by 30 ± 10 cmH₂O; p = 0.009 and 13 ± 4 cmH₂O; p = 0.007, respectively). Arterial oxygen saturation during training was higher (p = 0.002) for IE (94 ± 1%) compared to CLE (91 ± 1%), whereas dyspnoea scores were lower (p = 0.001) for IE (3.8 ± 0.7) compared to CLE (5.9 ± 0.8) CONCLUSIONS: IE is superior to CLE in improving peripheral and respiratory muscle strength and preferable to CLE because it is associated with lower exercise-induced arterial oxygen desaturation and breathlessness.

Assessing the Utility of an Outpatient Exercise Program for Children With Cystic Fibrosis: A Quality Improvement Project

Children with cystic fibrosis (CF) (cwCF) suffer from inadequate weight gain, failure to thrive, and muscle weakness. The latter may be secondary to disuse atrophy (muscle wasting or reduction in muscle size associated with reduced physical activity and inflammation). Handgrip strength (HGS) is a reliable surrogate for muscle strength and lean body mass. Data from our CF center have shown an association between low HGS and forced expiratory volume in 1 s (FEV₁) in cwCF. High-intensity interval training (HIIT) improves physical strength. Therefore, we devised a project to assess implementing a HIIT exercise program in the home setting, in order to improve physical strength in cwCF with HGS ≤ 50th percentile. Patients were instructed to complete 3-5 sessions of HIIT exercises per week. Wilcoxon matched-pairs signed-rank tests were used to compare HGS, FEV₁, and body mass index (BMI) percentile at baseline and at a follow-up clinic visit. Follow-up was limited due to the COVID pandemic. Adherence to the HIIT regimen was poor. A total of twenty-nine cwCF participated in the program. However, a total of 13 individuals reported some form of moderate activity at follow-up and therefore constituted our final study population. There was a statistically significant increase in absolute grip strength (AGS) and FEV₁ for these individuals. Even though the home HIIT protocol was not followed, the project demonstrated that moderate physical activity in cwCF can lead to significant improvement in HGS and overall physical strength.

Effects of a long-term exercise program on motor performance in children and adolescents with CF

OBJECTIVES

The aim of this study was to examine motor performance and trainability in youths with cystic fibrosis (CF).

METHODS

Twenty-two children and adolescents (11 f/11 m), age range 6-17 years (11.3 ± 3.3 years), mean FEV1 91.0 ± 21.7% pred.finished the partially monitored 12-months exercise program. Patients performed the Deutsche Motorik Test (DMT) to assess flexibility, balance, strength, power and totalmotor performance. An incremental ergometer cycle test was used to assess maximal exercise capacity (Wpeak). All tests were performed before (T1), after 6 months of monitored exercise training (T3) and another 6 months without monitoring (T4).

RESULTS

Motor Competence in total and test-items of the DMT (except foreward bend) improved to T3 (p < .05). No further improvement could be observed after the end of the monitoring (T3). However, the values remained stable at the improved level (T4). Girls scored lower in test items depending on strength/power but scored higher in balancing compared to boys (p > .05). Wpeak and FEV1 were not influenced by the training program. From T3 to T4 a slight decrease was observed (p ≤ .05).

CONCLUSIONS

The findings demonstrate benefits of an individualizedmonitored long-term exercise intervention on motor performance in CF with improvements of test-tasks to predicted normal. Monitoringseems to be a facilitator in maintaining motivation toward physical activity as no further increase in motor performance was observed after stopping supervision. The results suggest that an individually tailored monitoredregular exercise program should include all aspects of physical fitness with a variety of movement experiences.

High-Intensity Interval Training Is Effective at Increasing Exercise Endurance Capacity and Is Well Tolerated by Adults with Cystic Fibrosis

BACKGROUND

To optimize outcomes in people with cystic fibrosis (CF), guidelines recommend 30 to 60 min of moderate-intensity aerobic exercise on most days. Accumulating this volume of exercise contributes importantly to the substantial treatment burden associated with CF. Therefore, the main aim of this study was to investigate the effects of low-volume high-intensity interval training (HIIT) on exercise capacity in people with CF.

METHODS

This randomized controlled trial included people with CF aged ≥15 years, who were allocated to either eight weeks of thrice-weekly 10-min sessions of HIIT (experimental group) or eight weeks of weekly contact (control group). Before and after the intervention period, participants completed measurements of time to symptom limitation (T_lim) during a constant work rate cycle ergometry test (primary outcome), and maximal work rate (W_max) during a ramp-based cycle ergometry test and health-related quality of life (HRQoL).

RESULTS

Fourteen participants (median (IQR) age 31 (28, 35) years, forced expiratory volume in 1 second (FEV₁) 61 (45, 80) % predicted) were included (seven in each group). Compared to the control group, participants in the experimental group demonstrated a greater magnitude of change in T_lim, W_max (p = 0.017 for both) and in the physical function domain of HRQoL (p = 0.03). No other between-group differences were demonstrated. Mild post-exercise muscle soreness was reported on a single occasion by four participants. Overall, participants attended 93% of all HIIT sessions.

DISCUSSION

Eight weeks of low-volume (i.e., 30-min/week) HIIT produced gains in exercise capacity and self-reported physical function and was well tolerated by people with CF.

Reduced exertion high-intensity interval training (REHIT) in an adult with Cystic Fibrosis: A mixed-methods case study

Although aerobic capacity has been identified as an important predictor of mortality in Cystic Fibrosis (CF) individuals, many remain insufficiently active. As a 'lack of time' is a commonly cited barrier to exercise, reduced-exertion high-intensity interval training (REHIT) may provide a truly time-effective method to increase aerobic capacity. Six-weeks of REHIT in a CF individual was assessed by a cardiopulmonary exercise test (CPET) and individual perceptions described using a self-report narrative. Peak oxygen uptake (V ˙ O2peak) increased by 6% whilst pulmonary function remained unchanged. Qualitative data indicated social support and low-time commitment positively influenced adherence with fatigue and lack of enjoyment noted as a significant barriers. REHIT was demonstrated as a viable, manageable option for a CF individual with moderate-severe pulmonary limitation. Further research is needed to determine the efficacy of REHIT in a large representative sample to ascertain whether it represents an alternative treatment strategy.

High-intensity interval training accelerates oxygen uptake kinetics and improves exercise tolerance for individuals with cystic fibrosis

Background

Exercise training provides benefits for individuals with cystic fibrosis; however, the optimal program is unclear. High-intensity interval training is safe and effective for improving ‘functional capacity’ in these individuals with peak rate of O₂ uptake typically referenced. The ability to adjust submaximal rate of oxygen uptake (V̇O₂ kinetics) might be more important for everyday function because maximal efforts are usually not undertaken. Moreover, the ability of high-intensity training to accelerate V̇O₂ kinetics for individuals with cystic fibrosis could be enhanced with O₂ supplementation during training.

Methods

Nine individuals with cystic fibrosis completed incremental cycling to limit of tolerance followed by 8 weeks of high-intensity interval cycling (2 sessions per week x ~ 45 min per session) either with (n = 5; O2+) or without (AMB) oxygen supplementation (100%). Each session involved work intervals at 70% of peak work rate followed by 60 s of recovery at 35%. For progression, duration of work intervals was increased according to participant tolerance.

Results

Both groups experienced a significant increase in work-interval duration over the course of the intervention (O2+, 1736 ± 141 v. 700 ± 154 s; AMB, 1463 ± 598 v. 953 ± 253 s; P = 0.000); however, the increase experienced by O2+ was greater (P = 0.027). During low-intensity constant-work-rate cycling, the V̇O₂ mean response time was shortened post compared to pre training (O2+, 34 ± 11 v. 44 ± 9 s; AMB, 39 ± 14 v. 45 ± 17 s; P = 0.000) while during high-intensity constant-work-rate cycling, time to exhaustion was increased (O2+, 1628 ± 163 v. 705 ± 133 s; AMB, 1073 ± 633 v. 690 ± 348 s; P = 0.002) and blood [lactate] response was decreased (O2+, 4.5 ± 0.9 v. 6.3 ± 1.4 mmol^. L^− 1; AMB, 4.5 ± 0.6 v. 5.2 ± 1.4 mmol^. L^− 1; P = 0.003). These positive adaptations were similar regardless of gas inspiration during training.

Conclusion

Eight weeks of high-intensity interval training for patients with cystic fibrosis accelerated V̇O₂ kinetics and increased time to exhaustion. This provides some evidence that these patients may benefit from this type of exercise.

Trial registration

This study was retrospectively registered in the ISRTCN registry on 22/06/2019 (#ISRCTN13864650).

Effects of high intensity interval training on exercise capacity in people with chronic pulmonary conditions: a narrative review

BACKGROUND

Exercise training is important in the management of adults with chronic pulmonary conditions. However, achieving high intensity exercise may be challenging for this clinical population. There has been clinical interest in applying interval-based training as a strategy to optimise the load that can be tolerated during exercise training. Evidence for such an approach is limited in most chronic pulmonary populations.

MAIN BODY

In this narrative review, we provide an appraisal of studies investigating whole-body high intensity interval training (HIIT) in adults with chronic obstructive pulmonary disease (COPD). This is the first review to also include studies investigating HIIT in people with conditions other than COPD. Studies undertaken in adults with a chronic pulmonary condition were reviewed when participants were randomised to receive; (i) HIIT or no exercise or, (ii) HIIT or moderate intensity continuous exercise. Data were extracted on peak rate of oxygen uptake (VO2peak; 'cardiorespiratory fitness') and maximal work rate (Wmax; 'exercise capacity').In people with COPD, two studies demonstrated between-group differences favouring HIIT compared with no exercise. There appears to be no advantage for HIIT compared to continuous exercise on these outcomes. In people with cystic fibrosis (CF), no studies have compared HIIT to no exercise and the two studies that compared HIIT to continuous exercise reported similar benefits. In people prior to resection for non-small cell lung cancer, one study demonstrated a between-group difference in favour of HIIT compared with no exercise on VO2peak. In people with asthma, one study demonstrated a between-group difference in favour of HIIT compared with no exercise on VO2peak and one that compared HIIT to continuous exercise reported similar benefits. No studies were identified non-CF bronchiectasis or interstitial lung diseases.

CONCLUSIONS

High intensity interval training increases cardiorespiratory fitness and exercise capacity when compared with no exercise and produces a similar magnitude of change as continuous exercise in people with COPD. There is a paucity of studies exploring the effects of HIIT in other chronic pulmonary conditions.

Effects of aerobic interval training on glucose tolerance in children and adolescents with cystic fibrosis: a randomized trial protocol

Background

Individuals with cystic fibrosis (CF) may develop CF-related diabetes (CFDR). This comorbidity is related to a poorer quality of life, microvascular complications, a decline in lung function, and an increase in exacerbations, as well as delayed growth and puberty. Evidence exists that physical exercise contributes to glycemic control in individuals with non-CF-related diabetes. This exercise is usually continuous with moderate intensity and long duration, which can cause muscle dyspnea and fatigue in CF individuals. Aerobic interval training (AIT) emerges as a safe and effective alternative for treating these individuals. The objective of this study is to evaluate the effects of AIT on glucose tolerance in children and adolescents with CF.

Methods

This study will be a two-arm, prospectively registered, randomized controlled trial with blind assessors and twenty 6- to 18-year-old individuals with cystic fibrosis (CF) from two different Brazilian states. People with CF will be randomly allocated to either the experimental or control group using block randomization, stratified by puberty stage,. Participants from both groups will receive an educational intervention and will be asked to continue their usual daily treatment for the full duration of the study. Those in the experimental group will perform AIT on a cycle ergometer at home three times a week, for 8 consecutive weeks. The sample characterization will include an assessment of puberty stage, socioeconomic status, dyspnea, and anthropometry. The primary outcome will be the change in glucose tolerance, while the secondary outcomes will include lung function, exercise tolerance, respiratory muscle strength, quality of life, and CF exacerbations. All outcomes will be assessed at baseline, week 9, and week 17.

Discussion

This is the first study to evaluate the effects of AIT on glucose tolerance in children and adolescents with CF. This study will serve as a basis for guiding clinical practice and decision-making in treating glucose intolerance and CF-related diabetes (CFRD) in children and adolescents with CF.

Trial registration

ClinicalTrials.gov Protocol Registration System: NCT03653949. Registered on August 31, 2018.

Sildenafil improves exercise capacity in patients with cystic fibrosis: a proof-of-concept clinical trial

Background:

Exercise intolerance is a common phenotype observed in patients with cystic fibrosis (CF). Treatment with sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor, has previously been shown to improve exercise capacity (VO₂ peak) in other patient populations. Thus, the present study sought to determine the acute and subacute effects of sildenafil on exercise capacity in patients with CF.

Methods:

The present investigation utilized a randomized, double-blind, placebo-controlled, crossover study with an acute dose of either sildenafil (50 mg) or placebo (n = 13, age 25 ± 10), followed by a 4 week open-label extension with sildenafil (20 mg, TID; n = 15, age 23 ± 11). A comprehensive evaluation of pulmonary function and a maximal exercise test were each performed at every visit.

Results:

A significant increase in VO₂ peak was observed after the acute sildenafil dose with no changes following placebo (77 ± 13 versus 72 ± 13% predicted; p = 0.033). In addition, after 4 weeks of treatment, patients showed a significant increase in exercise capacity (72 ± 12 versus 75 ± 12% predicted; p = 0.028) and exercise duration (409 ± 98 versus 427 ± 101 s; p = 0.014). A robust correlation (r = 0.656; p = 0.008) between baseline FEV₁ (% predicted) and the change in exercise capacity following 4 weeks of treatment was identified.

Conclusions:

This proof-of-concept clinical trial demonstrates that sildenafil treatment can improve exercise capacity in patients with CF and that pulmonary function may play an important role in the effectiveness of treatment. Future investigations of sildenafil treatment in patients with CF are certainly warranted.

Variable agreement between wearable heart rate monitors during exercise in cystic fibrosis

In people with cystic fibrosis (CF), greater cardiorespiratory fitness is associated with improved survival and quality of life. Wearable activity monitors are a popular method of monitoring exercise, with measures of heart rate used to indicate exercise intensity. We assessed the agreement of heart rate recordings obtained using the Fitbit Charge HR^™, Polar® H7 heart rate sensor and Masimo SET® Rad-5v pulse oximeter with the three-lead ECG during continuous and interval exercise.

Adults with CF completed two exercise sessions, of 15-min duration per session, on a cycle ergometer while wearing the previously mentioned monitors. Firstly, participants cycled at 30% of estimated peak workload (W_peak). Secondly, participants cycled at 1-min intervals at 60% of W_peak interspersed with 2 min of unloaded cycling. Heart rate readings on all devices were recorded at minute intervals and their agreement was analysed using the Bland–Altman method.

The Polar® H7 heart rate sensor had the best agreement with three-lead ECG, with a bias of 0±1 bpm during both continuous and interval exercise. The Masimo SET® Rad-5v pulse oximeter had good agreement, with a bias of 1±7 bpm and 1±5 bpm during continuous and interval exercise, respectively. The Fitbit Charge HR^™ demonstrated less agreement, with a bias of 9±17 bpm and 5±13 bpm during continuous and interval exercise, respectively.

The Fitbit Charge HR^™ is not recommended for assessing heart rate during exercise in adults with CF. Findings support the use of the Polar® H7 for accurate heart rate monitoring.

The Fitbit Charge HR^™ does not provide accurate heart rate measurements during exercise in adults with cystic fibrosis. The Polar® H7 and Masimo SET® Rad-5v pulse oximeter do provide accurate measurements of heart rate.http://bit.ly/2KX0Yvy

Promotion of physical activity for adolescents with cystic fibrosis: a qualitative study of UK multi disciplinary cystic fibrosis teams

BACKGROUND

The Cystic Fibrosis Trust recently published a standards of care document which stated that patients should be given a physical activity (PA) programme based on their motivations, fitness, and willingness to be active. However, there remains much debate regarding the roles and responsibilities for PA promotion, as well as "optimal" recommendations and advice. This study aimed to qualitatively explore cystic fibrosis (CF) multidisciplinary teams (MDTs) advice, recommendations and practices relating to PA promotion for adolescents with CF.

METHOD

Semi-structured interviews were conducted with fifteen members of CF MDTs (11 physiotherapists, two dieticians and two paediatricians). Thematic analysis was used to analyse the data.

RESULTS

Major themes identified were: (1) structure of MDTs, (2) recommendations relating to intensities, durations and types of PA, and (3) use of exercise testing. Participants reported variation between MDTs in terms of who is responsible for promoting and supporting PA, the nature of advice given to patients, and the use of exercise testing. Participants consistently lacked confidence in their own or others' knowledge to provide standardised recommendations to patients and highlighted that PA promotion and support was often overlooked during busy periods.

CONCLUSIONS

Despite its importance, PA support and promotion is not always prioritised. MDTs lack confidence in their ability to promote PA. Standardised advice and training relating to optimal intensities, durations and types of PA would provide a baseline from which to individualise advice to each patient and could increase confidence in PA promotion among MDTs.

Improvement in body composition following a supervised exercise-training program of adult patients with cystic fibrosis

OBJECTIVES

Maintenance of optimal nutritional status is a crucial issue for cystic fibrosis (CF) patients. Here, we evaluate the effects of an 8-week exercise training (ET) program on body composition in CF patients.

METHODS

This prospective pilot observational study was conducted in adult CF subjects in stable condition following their annual check-up. The ET program consisted of three sessions per week and included aerobic training (≥30min), muscle strengthening, circuit training, and relaxation. Exercise tolerance (6-minute walk test, 6MWT), pulmonary function, quadriceps isometric strength, and body composition (bioelectrical impedance analysis of fat-free mass [FFM], fat mass, and body cell mass) were analyzed before and immediately after the ET program. A control group of CF patients who preferred not to participate in the ET program received the same evaluations.

RESULTS

A total of 43 CF patients were enrolled and offered the ET program; 28 accepted (aged 28±5 years, forced expiratory volume in 1s [FEV₁] 48.8±19% predicted) and 15 declined the ET program but agreed to be part of the control group (matched for age and CF severity: 30.8±9 years, FEV₁ 51.8±16.5%). Pulmonary function was unchanged at the end of the ET program, but significant improvements were observed in 6MWT distance (from 520±96m to 562±105m, P<0.001) and muscle strength (331±141N to 379±168N, P<0.001). Although mean body mass index did not change, the ET group showed significantly increased FFM (43.85±8kg to 44.5±9.2kg, P=0.03) and a trend towards increased body cell mass (21.4±6 to 22.1±6.6kg, P=0.06). All other parameters were unchanged by ET. There were no significant correlations between the increase in FFM and the improvements in either 6MWT distance or muscle strength. The CF control group exhibited no significant changes in any parameters between evaluations.

CONCLUSIONS

ET significantly improved FFM, but not body mass index, in CF patients. The results illustrate the superiority of bioimpedancemetry for assessing changes in body composition and reveal the importance of ET for improving not only exercise tolerance but also nutritional status in these patients.

The feasibility of online video calling to engage patients with cystic fibrosis in exercise training

Introduction

Physical activity, including structured exercise, is an essential component in the management of cystic fibrosis. The use of telehealth such as video-calling may be a useful method for the delivery of exercise and physical activity interventions, though the feasibility of this remains unknown.

Methods

Nine patients with cystic fibrosis (three female, six male, 30.9 ± 8.7 years) volunteered to participate. Participants completed an eight-week exercise training intervention conducted via Skype, using personalised exercises, with all sessions supervised by an exercise therapist. Feasibility was assessed by demand, implementation, practicality and acceptability. Changes in anthropometric, pulmonary, physical activity and quality of life variables were also assessed.

Results

Two male participants withdrew from the study, citing lack of available time. The remaining participants found use of Skype useful, with a mean satisfaction rating of 9/10, and three participants requesting to continue the sessions beyond the duration of the study. Mean compliance with sessions was 68%, with mean duration of sessions being 20 min. A total of 25% of calls suffered from technical issues such as video or audio lags. Anthropometric, pulmonary, physical activity and quality of life variables remained unchanged over the course of the study period.

Discussion

The use of Skype to deliver an exercise intervention to patients withcystic fibrosis was found to be technologically feasible, and acceptable among participants. Findings have implications for clinical practice and could allow care teams to engage patients remotely in exercise. Further research is required to assess the efficacy of this modality on increasing physical activity and associated health outcomes.

Effects of high intensity interval training on exercise capacity in people with cystic fibrosis: study protocol for a randomised controlled trial

BACKGROUND

In people with cystic fibrosis (CF), higher exercise capacity is associated with better health-related quality of life (HRQoL), reduced risk of hospitalisation for a respiratory infection and survival. Therefore, optimisation of exercise capacity is an important treatment goal. The Australian and New Zealand clinical practice guidelines recommend that people with CF complete 30 to 60 min of moderate intensity aerobic exercise on most days of the week. This recommendation can be difficult to achieve by people with CF because of time constraints, and intolerable breathlessness and muscle fatigue during continuous exercise. In contrast, a low-volume, high intensity interval training (HIIT) program may be a more achievable and efficient training method to improve exercise capacity in people with CF.

METHODS

A randomised controlled trial will be undertaken. Forty people with CF (aged ≥15 years) will be randomly allocated, on a 1:1 ratio, to either the experimental or control group. Regardless of their group allocation, all participants will be asked to continue with their usual daily treatment for the study duration. Those in the experimental group will complete 8 weeks of thrice weekly HIIT on a cycle ergometer. Those in the control group will receive weekly contact with the investigators. The primary outcome of this study is exercise capacity. Secondary outcomes are HRQoL, exercise self-efficacy, feelings of anxiety, depression and enjoyment. These outcomes will be recorded at baseline (i.e. prior to randomisation) and following the 8-week intervention period. The study will also report other outcomes of the HIIT program (cardiovascular responses, symptom response, post-exercise muscle soreness and tolerance) and behaviour change techniques such as reinforcement, feedback and goal setting, used during the HIIT program.

DISCUSSION

This study will determine the effects of 8-weeks of supervised, low-volume HIIT, completed on a cycle ergometer on measures of exercise capacity, HRQoL, exercise self-efficacy, feelings of anxiety, depression and enjoyment. If effective, this type of training could be an attractive alternative to traditional continuous training because it may be more achievable and time efficient.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ANZCTR):12617001271392 (04/09/2017).

Exercise Stroke Volume in Adult Cystic Fibrosis: A Comparison of Acetylene Pulmonary Uptake and Oxygen Pulse

Cardiac hemodynamic assessment during cardiopulmonary exercise testing (CPET) is proposed to play an important role in the clinical evaluation of individuals with cystic fibrosis (CF). Cardiac catheterization is not practical for routine clinical CPET. Use of oxygen pulse (O₂pulse) as a noninvasive estimate of stroke volume (SV) has not been validated in CF. This study tested the hypothesis that peak exercise O₂pulse is a valid estimate of SV in CF. Measurements of SV via the acetylene rebreathe technique were acquired at baseline and peak exercise in 17 mild-to-moderate severity adult CF and 25 age-matched healthy adults. We calculated O2pulse=V.O2HR. Baseline relationships between SV and O₂pulse were significant in CF (r = .80) and controls (r = .40), persisting to peak exercise in CF (r = .63) and controls (r = .73). The standard error of estimate for O₂pulse-predicted SV with respect to measured SV was similar at baseline (14.1 vs 20.1 mL) and peak exercise (18.2 vs 13.9 mL) for CF and controls, respectively. These data suggest that peak exercise O₂pulse is a valid estimate of SV in CF. The ability to noninvasively estimate SV via O₂pulse during routine clinical CPET can be used to improve test interpretation and advance our understanding of the impact cardiac dysfunction has on exercise intolerance in CF.

The treatment of the pulmonary and extrapulmonary manifestations of cystic fibrosis

Cystic fibrosis (CF) is a complex multisystem disease with considerable between patient variability in its manifestations and severity. In the past several decades, the range of treatments and the evidence to support their use for the pulmonary and extrapulmonary manifestations of CF have increased dramatically, contributing to the improved median survival of patients. As therapy for CF has evolved, new challenges including treatment adherence, medication intolerance and allergy, medical complications and coping with the burden of disease in the context of having a family and managing employment have arisen. While the majority of current therapy focuses primarily on improving symptoms, new therapies (CFTR modulators) target the underlying genetic defect.

Exercise as medicine - evidence for prescribing exercise as therapy in 26 different chronic diseases

This review provides the reader with the up-to-date evidence-based basis for prescribing exercise as medicine in the treatment of 26 different diseases: psychiatric diseases (depression, anxiety, stress, schizophrenia); neurological diseases (dementia, Parkinson's disease, multiple sclerosis); metabolic diseases (obesity, hyperlipidemia, metabolic syndrome, polycystic ovarian syndrome, type 2 diabetes, type 1 diabetes); cardiovascular diseases (hypertension, coronary heart disease, heart failure, cerebral apoplexy, and claudication intermittent); pulmonary diseases (chronic obstructive pulmonary disease, asthma, cystic fibrosis); musculo-skeletal disorders (osteoarthritis, osteoporosis, back pain, rheumatoid arthritis); and cancer. The effect of exercise therapy on disease pathogenesis and symptoms are given and the possible mechanisms of action are discussed. We have interpreted the scientific literature and for each disease, we provide the reader with our best advice regarding the optimal type and dose for prescription of exercise.

[Impact of physical exercise in cystic fibrosis patients: A systematic review]

INTRODUCTION

Beneficial effects of physical exercise have been previously demonstrated in patients with chronic obstructive pulmonary disease. The aim of this systematic review was to summarize the evidence supporting physical exercise to improve on lung function, exercise capacity and quality of life in cystic fibrosis patients.

METHODS

Medline database was used to search clinical studies from 2000 to 2015. We also analyzed the bibliographic section of the included studies, in order to identify additional references.

RESULTS

A total of 17 studies were identified. A great disparity was found in the results of the different studies. No systematic benefit was found on lung function, exercise capacity or quality of life. No relationship between the type of program and the benefits achieved was observed.

CONCLUSIONS

Evidence that physical exercise benefits lung function, exercise capacity and quality of life in cystic fibrosis patient is inconsistent and evidence does not support a particular standardized program for all patients.

Exercise for all cystic fibrosis patients: is the evidence strengthening?

PURPOSE OF REVIEW

Regular physical activity and exercise have become important components of cystic fibrosis care. This review summarizes the recent evidence in favour of regular exercise in cystic fibrosis that has accumulated over the past years.

RECENT FINDINGS

Several recently published small randomized-controlled trials and observational studies have added to our knowledge on positive effects of exercise training on pulmonary function and aerobic fitness in cystic fibrosis. Relevant outcomes, such as body posture, health-related quality of life and rate of hospitalization, are increasingly studied. Findings from these studies suggest that exercise might also be beneficial for these outcomes. So far, many important questions such as the best way of integrating exercise in cystic fibrosis care and the determination of the optimal strategies for training and motivation remain mostly unanswered.

SUMMARY

Over the past years, evidence for the beneficial effects of regular exercise on lung health and aerobic exercise capacity is strengthening. Despite the fact that most of the knowledge is based on small studies, the observed effects are encouraging and there is no reason why exercise should not be implemented in all patients' care.

Airflow limitation following cardiopulmonary exercise testing and heavy-intensity intermittent exercise in children with cystic fibrosis

The clinical importance of exercise testing and training in the healthcare management of young patients with cystic fibrosis (CF) is growing. The aim of the present study was to determine the incidence of airflow limitation following cardiopulmonary exercise testing (CPET) and heavy-intensity intermittent exercise (HIIE) in young patients with CF. Nineteen young patients with CF and respective paired-matched controls performed CPET and HIIE on separate days. Forced expiratory volume in one second (FEV1) was measured pre- and post each exercise modality. A fall in FEV1 of 10 % or greater was used to define airflow limitation. The incidence of airflow limitation was significantly greater in the CF group than in the controls following CPET (32 vs. 5 %; p = 0.03); however, no significant difference in the incidence of airflow limitation was shown following HIIE between the CF group and controls (11 vs. 16 %; p = 0.64).

CONCLUSION

Our data show that the incidence of airflow limitation following CPET in young patients with CF is high. Therefore, clinicians may wish to identify whether young CF patients experience airflow limitation following strenuous exercise, such as CPET, before it is performed. However, HIIE carries a low risk for airflow limitation and may be prescribed as a safe, yet effective exercise modality for young patients with CF.

Effects of exercise intensity compared to albuterol in individuals with cystic fibrosis

BACKGROUND

Although exercise is a vital component of the therapy prescribed to individuals with cystic fibrosis (CF), it is not a priority due to a finite amount of treatment time and the view that exercise is not as beneficial as pharmacological treatments by many individuals with CF. We sought to compare the therapeutic benefits of exercise and their prescribed bronchodilator albuterol.

METHODS

CF (n = 14) and healthy (n = 16) subjects completed three visits, a baseline screening with VO2 max test and two treatment visits. On the two treatment visits, subjects completed spirometry and diffusing capacity of the lungs for nitric oxide (DLNO) maneuvers either at baseline, 60, and 110 min post-albuterol administration, or at baseline and the midway point of three separate 15 min exercise bouts at low, moderate and vigorous intensity (25, 50 and 65% of the maximum workload, respectively).

RESULTS

With moderate exercise the increase in DLNO was double (39 ± 8 vs 15  ± 6% change) and the level of bronchodilation similar (23% change) when compared to 110 min post-albuterol in individuals with CF. During exercise FVC became reduced (-309 ± 66 mL with moderate exercise) and the increase in FEV1 was attenuated (103 ± 39 vs 236 ± 58 mL, exercise vs. albuterol) when compared with the response to albuterol in individuals with CF. Epinephrine (EPI) release increased 39, 72 and 144% change with low, moderate and vigorous intensity exercise respectively for individuals with CF, but this increase was blunted when compared to healthy subjects.

CONCLUSION

Our results suggest that moderate intensity exercise is the optimal intensity for individuals with CF, as low intensity exercise increases EPI less than 50% and vigorous intensity exercise is over taxing, such that airflow can be restricted. Although the duration of the beneficial effect is uncertain, exercise can promote greater improvements in gas diffusion and comparable bronchodilation when compared to albuterol.

Pulmonary rehabilitation for respiratory disorders other than chronic obstructive pulmonary disease

Pulmonary rehabilitation (PR) is an important therapeutic intervention that should no longer be considered suitable only for patients with chronic obstructive pulmonary disease (COPD). A strong rationale exists for providing PR to persons with a broad range of respiratory disorders other than COPD. Evidence shows that PR for these patients is feasible, safe and effective. A disease-relevant approach should be undertaken, based on individual patients' needs. Further research is needed to better understand the optimal program content, duration and outcomes measures, to enable diverse patients to achieve maximal benefits of PR.