Standardisation of the Dmax method for calculating lactate threshold

Chalmers, Samuel, Esterman, Adrian, Eston, Roger, and Norton, Kevin (2015) Standardisation of the Dmax method for calculating lactate threshold. International Journal of Sports Physiology and Performance, 10 (7). pp. 921-926.

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Abstract

Purpose: The purpose of this study was to test the reliability and validity of two standardised methods for calculating speed at the second lactate threshold point (LT2) based upon the pre-existing Dmax (LTD) and modified Dmax (LTMOD) procedures.

Methods: 13 trained male road runners and triathletes completed two incremental laboratory running tests to determine LT2 followed by separate time-trials (5, 10, 15 km) on an outdoor running track. Two new methods were proposed for calculating the speed at LT2; 1) the single standardised lactate threshold (LTSDs), and 2) the paired standardised lactate threshold (LTSDp) for quantifying changes over time.

Results: The LTSDs and LTSDp methods had high relative (ICC≥0.98) and absolute (CV≥1.9 %) reliability in identifying the speed at LT2. The speed at LT2 according to the LTSDs and LTSDp methods had a strong correlation and was not different to the performance speed during the 10 and 15 km time-trials (≥2.4 %; ρc>0.8; p>0.05). The following natural log-based formula was created to estimate the percentage of LT2 speed (using the LTSDs method) that could be sustained for events ~15-75 min: y= -7.256 (lnx) + 157.64 (y=%LT2 speed, x=time-trial performance [s], ln=natural log).

Conclusions: The standardised methods are reliable for determining LT2. The LTSDs and LTSDp methods for calculating the speed at LT2 from a near-maximal incremental test calculated speeds similar to those exhibited in 10 and 15 km running time-trials. A prediction equation for estimating the percentage of LT2 that can be sustained for events of ~15-75 min was generated.

Item ID: 39135
Item Type: Article (Research - C1)
ISSN: 1555-0273
Keywords: time trial, anaerobic threshold, prediction, running, blood lactate
Date Deposited: 12 Nov 2015 03:38
FoR Codes: 11 MEDICAL AND HEALTH SCIENCES > 1106 Human Movement and Sports Science > 110602 Exercise Physiology @ 100%
SEO Codes: 92 HEALTH > 9202 Health and Support Services > 920203 Diagnostic Methods @ 100%
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