The effect of sampling time on blood lactate concentration ([Bla]) in trained rowers

Purpose : To compare blood lactate concentration ([Bla]) at 15 s and 45 s during the 1-min rest period between each stage of an incremental test in rowers and to establish the validity of using interchangeable sampling times. Methods : Seventeen male club rowers (mean ± SD, age 28.8 ± 5.7 years, height 186.9 ± 5.1 cm, body mass 85.4 ± 6.6 kg) performed an incremental rowing ergometer test, consisting of five stages of 4 min corresponding to approximately 80% HRmax. A 10-μL earlobe blood sample was collected from each subject at 15 s and again at 45 s in the final minute of each test stage and analyzed in duplicate. A maximum of 10 s was allowed for blood collection. Results : Statistical analysis using limits of agreement and correlation indicated a high level of agreement between the two [Bla] samples for all five test stages (agreement >95%, confidence intervals [CI] = −0.5 to 1.5, r = .97, P < .05). Conclusion : These results suggest that a sampling time between 15 s and 45 s may be recommended for the valid assessment of the [Bla] threshold in rowing performance monitoring. This extends the current sampling time of 30 s used by physiologists and coaches for National and club-level Rowers.