The investigators wish to study 50 healthy volunteer subjects (not NHS patients) as follows: 18-28 y men (10) and 65-75 y men (40) of comparable body mass index (24-28 kg•m2) all of whom are sedentary and normally undertake no customary resistance training. The investigators have data suggesting sexual dimorphism of anabolic responses to feeding in older subjects so will restrict studies to men only. After obtaining written consent, all subjects will undergo a medical examination, activity questionnaire and DEXA scan. Ten elderly men will undergo a single acute study. In addition the investigators will study 10 young men under the same conditions. Ten more elderly men will undergo an acute study after 20 weeks of supervised whole-body resistance training, as is current practice at a gym site in Derby. Ten more elderly men will undergo a single acute study in which they are given, in addition to the standard acute study protocol 3 drinks of high flavanol cocoa and 3 x 500 mg of vitamin C. If a positive acute effect of the drinks is observed the final ten elderly men will undergo an acute study after a week of ingesting 3 high flavanol cocoa + 1000 mg of vitamin C per day. To optimise details of study conditions the investigators will also study up to 10 normal healthy volunteers 18-75 y simply with the CEUS contrast agent and methacholine infusions, without any blood sampling or biopsies.