"Those athletes given growth hormone improved their sprint capacity by 4-5%," said Professor Ho.

"Growth hormone recipients did not increase their muscle mass. They did, however, retain body fluid and experienced swelling and joint pain, unlike those who received salt water injections."

"We used lower doses of growth hormone than athletes are reported to use, and for a shorter time. We can speculate, therefore, that the drug's effects on performance might be greater than shown in this study, and its side effects might be more serious."

"In conclusion, growth hormone increases athletic sprinting when given alone or in combination with testosterone. This is the first demonstration of improvement in a selective aspect of physical performance with growth hormone. We believe that this effect may bring a competitive advantage to athletes engaging in sprint events."

Source: Research Australia