F-14 Free Communication/Slide - Endocrinology: JUNE 4, 2010 1:00 PM - 2:30 PM: ROOM: 308
Rock climbing is rapidly increasing in popularity as a recreational activity and as a competitive sport. Few studies have tested physiological responses to acute bouts of climbing, and no studies have tested hormone responses to climbing as a form of cardiovascular exercise.
PURPOSE: To measure testosterone (T), growth hormone (GH), and cortisol (C) responses to continuous vertical climbing in young male rock climbers.
METHODS: Ten male rock climbers ages 21-30 years were assigned to a submaximal 55' climbing route based on their consistent top rope climbing ability. Subjects climbed laps on their route for 30 minutes, or until exhaustion, whichever came first. Subjects were not allowed to weight the rope or rest on holds during climbing, and were allowed to stop only long enough to chalk their hands. Heart rate (HR) and rating of perceived exertion (RPE) were recorded after every lap. Water was offered between laps ad libitum. Blood samples were collected by venipuncture Pre, immediately post (IP), and 15 minutes after the climbing exercise (P15). Hematocrit was assessed for each sample, and lactate was measured at pre and IP. Plasma C and T concentrations were measured using radioimmunoassay, and GH was measured using ELISA. Body composition variables (bone free lean body mass, fat mass) were assessed using DXA (GE Lunar Prodigy, enCORE version 10.50.086).
RESULTS: Subjects climbed 24.9 ± 1.9 min and 507.5 ± 82.5 feet. Six subjects climbed longer than 25 minutes. Peak HR was 182.1 ± 2.3 bpm, and lactate (Pre: 2.9 ± 0.6 mmol/dL, IP: 11.1 ± 1.0 mmol/dL) significantly (p < 0.05) increased from Pre to IP. T concentrations significantly (p < 0.05) increased from Pre (6.04±0.31 ng/mL) to IP (7.39 ± 0.40 ng/mL), and returned to baseline at P15 (6.23 ± 0.33 ng/mL). Cortisol levels did not significantly change during the protocol. GH significantly (p < 0.01) increased from Pre (0.63 ± 0.17 ng/mL) to IP (19.89 ± 4.53 ng/mL), and remained elevated at P15 (15.03 ± 3.89 ng/mL). Fat mass values were inversely (p < 0.05) correlated with T Pre values (r = -0.67) and positively correlated with C Pre values (r = 0.74). T P15 values were related (p < 0.05) to GH IP and P15 values (r = 0.77 and 0.71, respectively).
CONCLUSIONS: An acute, short-term bout of continuous climbing was effective for elevating plasma testosterone and growth hormone levels in young males.