Pulmonary Rehabilitation for Uncontrolled Asthma Associated With Elevated BMI

Inclusion Criteria:

1. Adults aged 18-80 year (smokers, ex-smokers and non-smokers)
2. Confirmed asthma as per Global Initiative for Asthma (GINA) guidelines 2015\[4\] with characteristic symptoms and at least one of the following:

   * Airflow limitation - FEV1/FVC \< 70% (at any time in the past) and 12% and 200ml increase in FEV1 in the preceding 5 years either:

     i. After inhaled/nebulised bronchodilator or 4+ weeks of anti- inflammatory treatment ii. Between visits
   * Positive bronchial challenge in the preceding 5 years:

   I. Histamine or methacholine provocation concentration causing a 20% drop in FEV1 (PC20) \<8mg/ml ii. Provoking dose of mannitol required to cause a drop in FEV1 of 15% (PD15) mannitol \<635mg
3. Difficult asthma defined as per Scottish Intercollegiate Guidelines Network(SIGN)/British Thoracic Society(BTS) guideline 2014 as persistent symptoms and/or frequent asthma attacks despite treatment at step 4 or step 5 with either:

   * ACQ6\>1.5
   * ≥2 systemic corticosteroid boosts in previous year
   * ≥1 hospitalization in previous year
4. BMI≥25 kg/m2
5. MRC dyspnoea scale ≥3/5

Exclusion Criteria:

1. ICU admission +/- mechanical ventilation in the previous year for asthma exacerbation
2. Respiratory tract infection requiring antibiotics or asthma exacerbation requiring corticosteroid boost in preceding 4 weeks
3. Significant respiratory or other co-morbidity likely to influence the conduct of the study
4. Pregnancy and breast feeding
5. Severe and/or unstable cardiac disease
6. Impaired mobility that impacts on ability to participate in physical training
7. Recent (within the preceding 6 months) commencement of antifungal, biologic (omalizumab, lebrikizumab, mepolizumab) or Airsonett device; eligible if on treatment for \>6months or discontinued \>6 months ago.