Assessing inter-effort recovery and change of direction ability with the 30-15 intermittent fitness test

The aim of the present study was to propose a new and simple field assessment of inter-effort recovery and change of direction (cod) ability based on performance during the 30-15 intermittent fitness test (30-15ift,an intermittent,incremental shuttlerun test) using three different protocols. forty team-sport players (22 ± 2 years) performed either (group a; n = 16) the original 30-15ift and two modified versions,one without a rest period (i.e. continuous run,30-15ift-cont) and one without cod (30- 15ift-line),or (group b; n = 24) the original 30-15ift and a modified version with more cod (28-m shuttle instead of 40-m,30-15ift-28m). heart rate (hr),blood lactate concentration ([la]b),rating of perceived exertion (rpe) and maximal running speed were recorded for all tests. there was no statistical difference in either maximal hr (a: p = 0.07 and b: p = 0.94) or rpe (a: p = 0.10 and b: p = 0.97) between tests. compared with the 30-15ift (12.3 ± 2.5,p < 0.01) and 30-15ift-line (11.3 ± 2.6,p = 0.07,es = 0.61),[la]b was lower for 30-15ift-cont (9.6 ± 3.3mmol.l-1). compared with 30-15ift,maximal running speed was higher for 30-15ift-line (103.1 ± 1.7%,p < 0.001) and lower for 30-15ift-cont (93.2 ± 1.4%,p < 0.001),while it was similar for 30-15ift-28m (99.7 ± 3.6%,p = 0.62). maximal speeds reached after the four tests were significantly but not perfectly correlated (r = 0.74 to 95,all p < 0.001). present results show that differences in the maximal running speed reached following different versions of the 30-15ift can be used by coaches toisolate and evaluate inter-effort recovery (i.e. 30-15ift vs. 30-15ift-cont) and cod (i.e.,30-15ift vs. 30-15ift-line) abilities in the field. additionally,cod ability as evaluated here appears to be independent of shuttle-length. © journal of sports science and medicine.