The effects of 12 weeks of resistance training combined with 5:2 intermittent fasting or continuous energy restriction on body composition, strength, compliance and gut microbiome.

Participants were randomly assigned to 1 of 2 dietary groups: 1. 5:2 intermittent fasting - participants were required to consume 100% of their estimated energy requirements 5 days per week, and ~30% of estimated energy requirement on 2, non-consecutive, non-exercising days per week (fasting days). Fasting day intake consisted of protein shakes, protein soups (provided to participants) and raw/steamed vegetables or; 2. Continuous energy restriction - participants were required to consume ~80% of their estimated energy requirements each day. Both groups aimed to consume >=1.4 grams of protein per kilogram of body weight per day on average. Participants were provided with customised meal plans and dietary advice at the beginning of the study by an accredited practising dietitian. The consultation with the dietitian lasted approximately 30 minutes, however, as the dietitian was also responsible for supervising the resistance training sessions (detailed below), participants had consistent contact with the dietitian over the 12 week intervention (~twice per week). In addition, all participants were asked to undertake 12 weeks of resistance training consisting of: - 2 full body workout sessions per week last approximately 45 minutes supervised by a strength and conditioning coach and dietitian at Swinburne University's Hawthorn (Victoria) campus. These were conducted in groups consisting of <6 individuals at any one time, and consisted of exercises in a super-set format (one exercise followed immediately by another, followed by a break). The super-sets included push-ups and squats, rows and lunges, bicep curls and dips, or variations of these exercises tailored to the individual's ability. Once participants could complete 3 sets of 15 repetitions of any of these exercises, the variation was made more difficult or weight added and; - 1 unsupervised full body aerobic/resistance training combination session per week lasting approximately 30 minutes, which consisted of timed super-sets of the following exercises: planks and mountain-climbers, crunches and burpees, side toe touches and hip bridges. Participants were encouraged to increase the time (from a base of 30 seconds for each exercise) once they could complete the exercise for that time period with good form (self-assessed). While effort level was not formally assessed, participants were encouraged and motivated throughout their supervised workouts to ensure a high level of effort. The unsupervised sessions were not assessed for effort, and participants were required to self-motivate. Attendance was recorded at each session, and participants were asked each week whether or not they had completed their unsupervised training session. Changes in whole body composition were measured by dual x-ray absorptiometry and local muscular changes in the non-dominant thigh were measured using muscle ultrasound and pQCT. Dietary intake was assessed utilising 3 day electronic food diaries at baseline, week 1, 6 and 12 of the intervention. Blood samples were taken from an antecubital vein at baseline and after the intervention to assess changes in blood cholesterol, high sensitivity CRP, blood glucose and insulin levels. Dietary compliance, as well as changes in hunger, mood and energy levels were measured using daily surveys. Changes in gut microbiome in response to each diet were measured using DNA sequencing of frozen faecal samples collected at baseline and at the end of the intervention.