This project aims to investigate the impact of VLCD on MPS, insulin sensitivity, muscle structure and function (strength), cardiopulmonary fitness in overweight and obese middle-aged adults with or without RET or HIIT. The investigators hypothesised that VLCD will impair MPS and slightly reduce muscle thickness and function, and cardiopulmonary fitness, while exercises will improve MPS and muscle structure and function. All group will show overall improve in insulin sensitivity.