Reflotron systems spectrophotometer

Capillary (fingertip) blood samples were collected to assess CK activity. Approximately 30μL of capillary blood was collected from a finger via a prick made with a spring-loaded lancet (Accu-Check, Roche Diagnostics, Germany) set at 2.3 mm depth. A Reflotron applicator with a 32 μL disposable pipette tip was used to extract a 32 μL sample of blood and place it on a CK magnetic test strip (Reflotron ® CK strips, UK). The blood sample was immediately analysed using a Reflotron® systems spectrophotometer (F.Hoffman-La Roche Ltd, Basel, Switzerland) for plasma CK activity. The normal reference range for CK using this method is 50 to 220 IU•L-1 and the assay can accurately detect values between 20 and 2000 IU•L-1, according to the manufacturers' manual.

Approximately 30µL of capillary blood was collected from a finger via a prick made with a springloaded disposable lancet (Accu-Check, Roche Diagnostics, Germany). The blood sample was immediately analysed using a colorimetric assay procedure using a Reflotron ® systems spectrophotometer (F. Hoffman-La Roche Ltd, Basel, Switzerland) for plasma CK activity. The coefficient of variation for inter and intra-assay variation were 3.5 and 3.7% respectively.

Saliva was collected and CK measured using previously described techniques 17 . Saliva samples were analysed in duplicate according to manufacturer's instructions using an enzymelinked immunosorbent assay (ELISA; DRG International, USA). The coefficient of variation (CV) of duplicate ELISA samples was 3.9% for testosterone and 8.5% for cortisol. The typical CV of CK measurements using the Reflotron® systems spectrophotometer (Roche Diagnostics, Switzerland) is 3.5%. The Daily Analysis of Life Demands in Athletes (DALDA) questionnaire was then completed by participants (as well as prior to each training session, as part of the training records kept by participants). The frequency of 'worse than normal' results was recorded at each testing session and was analysed to determine any changes across testing sessions. This questionnaire has been used previously to monitor athletes 18, 19 .