Mood, quality of life and sexual well being will be assessed using validated questionnaires. In addition, we will utilise the GCRC facility to measure body composition using total body water and DEXA. We will measure insulin sensitivity, exercise performance, muscle fatigability and VO2 max. Pre- and post- intervention muscle biopsies will assess DHEA(S) effects on myosin heavy chain isoform expression; skeletal muscle mitochondrial ATP production and be used to assess muscle enzyme levels.