In addition, almost a third of eligible patients declined to participate in the study, primarily due to lack of time. Low levels of recruitment and participation may be a recurring challenge for intervention research in Barrett��s oesophagus. By analogy, a dietary and weight loss trial targeting a very similar patient population in the US with biomarker endpoints had a similar rate of recruitment as this study. Due to the minimal adverse events reported, future trials should consider using less strict eligibility criteria and/or recruiting across multiple cities. Direct mailing of study information sheets to patients identified from hospital and research databases, was the most effective recruitment strategy in this study. Use of a dedicated clinical trials/research nurse to identify and recruit patients in clinics, rather than relying on clinicians to provide study information to patients during routine appointments, would also assist with recruitment. Subsequent effectiveness-based trials which used different or more flexible strategies for increasing BD 1047 dihydrobromide exercise participation, may assist to increase the reach and representativeness of those recruited into the trial. The exercise protocol included one supervised and four unsupervised sessions. While adherence to the single supervised session was good, adherence to the four independent gym-based exercise sessions was moderate. Previous exercise trials for primary prevention of cancer have included 2�C3 supervised sessions per week with the unsupervised sessions primarily as home-based exercise. A greater number of supervised exercise sessions may have improved adherence to the exercise protocol in the current study. Furthermore, almost a third of participants in the attention control group reported exercising for more than one hour per week on at least five weeks over the study period; thus the intervention effects observed on the primary outcomes may be underestimated. To minimise contamination, stretching sessions were held at different times to the exercise group sessions and attention control group participants were instructed to maintain their usual physical activity levels. However Astemizole contamination is common in exercise trials, where participants can freely choose to engage in the ��active treatment��, as opposed to placebo-controlled drug trials. Contamination rates in control groups in other exercise trials have ranged from 12% to 52%, which serve to under-estimate the treatment effect. In this trial, a statistically significant reduction in waist circumference was observed after 24-weeks of exercise, compared to attention-control stretching. Visceral adiposity has recently been shown to be a more important risk factor for oesophageal adenocarcinoma than measures of overall obesity. The reduction in waist circumference following the exercise intervention may therefore confer an important reduction in cancer risk for these men with Barrett��s oesophagus.