Individual Anaerobic Threshold: Methodological Aspects of its Assessment in Running

Abstract

The present study was designed in order to examine the objectivity and reliability of the individual anaerobic threshold (IAT) as well as its resistance against several interfering factors: missing exhaustion, preliminary exercise, longer step duration, and lower speed increment. 87 male and 24 female runners and triathletes were examined. They performed both the original test procedure (IAT(3/2); 3 min step duration, 2 km x h(-1) increment until volitional exhaustion) and either a retest or one of several alternative test procedures (submaximal, preliminary exercise, 5 min step duration, 1 km x h(-1) increment) to be compared with IAT(3/2). The graphic determination of the IAT is characterized by a low inter-observer-variability without significant differences between 4 independent blinded examiners. Both the lactate performance curve (p = 0.07) as well as the heart rate performance curve (p = 0.05) show a slight shift to higher velocities during the retest. The IAT shows an identical running velocity during the retest, the heart rate tends to be lower, and the lactate concentration is significantly (by 0.26 mmol x l(-1); p < 0.05) lower than during the first test. Both a low degree of exhaustion (3-6 mmol x l(-1) lactate; IAT(3/2) shortened by 180 s) and an extension of the step duration from 3 to 5 min do not lead to significantly different velocities at the IAT. Moderate preliminary exercises (approximately 4 mmol x l(-1) lactate) do not influence the velocity at the IAT, the heart rate is significantly higher. A reduction of the speed increment from 2 to 1 km x h(-1) significantly increases the velocity at the IAT by 6%. It is concluded that the determination of the IAT is highly objective, reliable and insensitive to changes of the incremental graded testing protocol, such as a previous warm-up, an extension of the step duration from 3 to 5 min as well as a lower degree of exhaustion. Significant differences may only arise from changes in the speed increment.

Efeitos do uso da máscara para análise de gases sobre variáveis fisiológicas e perceptuais máximas e submáximas durante um teste incremental

“…Previous studies demonstrated V peak is a reliable variable in a test-retest protocol, with high intraclass correlation coe cient and low bias risk [18][19][20] . However, these studies measured V peak in association with VO 2max (i.e., using gas analysis mask) and blood collection (i.e., to assess lactate threshold).…”

“…Previous studies suggest that HR at submaximal stages has a high reliability; however, their values tend to be lower in the re-test 20,[24][25][26] , possibly due to a subjects' familiarization to the protocol 25 . Nevertheless, in the present study, the tests protocols (i.e., with or without the mask) were performed in a randomized order, reducing potential bias associated with this factor.…”

“…20 e maximum aerobic velocity (MAV) predicts running performance of middle and long distance athletes [1][2] . Moreover, it can be used in the control and prescription of exercise training 3 .…”

Reproducibility of lactate markers during 4 and 8min stage incremental running: A pilot study

“…11 Longer stages may decrease variance in speed at particular markers between test-retest trials. It is likely that prolonged stages allow stabilisation between arterial and muscle lactate concentrations, facilitating lactate steady state, thus 9 limiting differences in lactate diffusion capacity for the sprint and endurance trained.…”

“…In addition to highlighting the importance of supplementing correlation coefficient analysis with LoA, these results also suggest greater reproducibility for individuals of greater aerobic fitness. Reproducibility of the 4.0 mmol·l -1 marker has also been reported for repeated incremental running 11 and cycling trials. 12 Recently, the measurement error of several markers was examined for the lactate-power relationship during incremental cycling of 3 min stages.…”