The prospect of future positive tests from human growth hormone (hGH) have increased following a communication from the World Anti Doping Agency (WADA) to anti-doping organisations that they should knuckle down to searching for signs of the substance.

“WADA has taken the opportunity to remind anti-doping organizations (ADOs) that had previously stored blood serum samples for future hGH analysis that they should now proceed with retrospective analysis using the hGH Isoform Differential Immunoassays test,” it said in a statement.

HGH is a substance which has considerable performance enhancing benefits, and which has a history of being abused in cycling and other sports.

However testing for it was put on hold in 2013 after a Court of Arbitration appeal by two-time Olympic cross-country skiing champion Andrus Veerpalu. He managed to get his three-year doping ban overturned on a statistical technicality, with CAS concluding false positives were possible.

Additional research was carried out and in June WADA issued guidelines listing the revised decision limits to be used with the hGH isoforms method.

WADA has also called on anti-doping organisations who have conducted minimal blood testing to consider expanding their programs “to reflect the risk of hGH abuse by their athletes.”

Meanwhile the Mouvement Pour Un Cyclisme Crédible (MPCC) anti-doping organisation has published statistics which show that cycling is one of the sports which does the most in terms of testing. The important points are:

1) A total of 22, 252 anti-doping tests were carried out by cycling in 2013, exceeded only by football (28,002) and athletics (24,942). However the MPCC notes that cycling has 1,300 professional riders globally, 600 less than the number of those who participated in the Athletics World Championships. It also points out that football lists 113,000 professional players on five continents, almost ten times the number of pro bike riders.

The next biggest number of tests in sport are the 11,585 conduced on swimmers. This number is almost half the level of tests done on cyclists.

2) Cycling’s figure included a gain of 1,628 over the 2012 figures. In contrast, football did six fewer tests than its 2012 level, while athletics saw a drop of 2,884.

3) Cycling had by far the biggest number of blood tests. 1,224 of the tests carried out on riders used this method, with athletics doing 831 such tests, football doing 667, tennis doing 657 and rugby doing just 380.

4) Cycling also has the highest number of tests for EPO with 7,322. Athletics and football are second and third but, despite those sports’ higher participation numbers, just 5,227 and 2,379 respectively are tested.

5) Cycling is second to athletics in terms of testosterone checks, 941 to 860, while the same two sports are first and second in terms of tests for hGH. Athletics did 423 tests in 2013 and cycling did 396. Football is only eighth in the latter category, conducting just 135 examinations.