A recent study in the Journal of Sports Physiology and Performance, January 22 2013 studied a drug free athlete in his prep for a bodybuilding competition.
During a six month diet phase, his heart rate fell from a resting 53bpm to 27bpm. Blood pressure dropped from 132/69 to 104/56 and body fat dropped from 14.8% to 4.5%.
In a negative sense, testosterone levels dropped by 75% and took 6 months to recover to old levels, as did strength. It also was noted it caused significant mood disturbance (that is to say, it was registered he felt he was reacting differently to how he ‘usually’ did).
The study concluded that prep is a challenging process both mentally and physically as demonstrated by the data gained on his various vital signs.
Taken from Journal of Sports Physiology and Performance, January 22 2013.
