Author(s): SCHÜNEMANN, F., POHL, A., GEHLERT, S., Institution: UNIVERSITY OF HILDESHEIM, Country: GERMANY, Abstract-ID: 1023

INTRODUCTION:
In elite sports, the determination of anaerobic glycolytic performance (νLa.max) is becoming increasingly popular. νLa.max is determined e.g. in sprint tests, where firstly glycolysis is maximally activated, followed by the calculation of the quotient between the difference of peak blood lactate (Lapeak) and resting lactate (Larest), and the difference between exercise time and alactic time is calculated. Unintentional variations in lactate levels, such as elevated Larest levels, may affect vLa.max results because of their high impact on the numerator in this calculation.
Aim: To evaluate the effects of variations in carbohydrate availability and Larest on VLamax.
METHODS:
Twenty-one subjects (13 male, 8 female; age: 23.1 ± 2.0 years, height: 177.1 ± 8.4 cm, weight: 74.2 ± 11.9 kg) completed five 15-second running sprint tests on five separate testing days under five different conditions: baseline: Larest ≤1.5 mmol·L-1; lactate+: Larest ≥2.5 mmol·L-1; CHO-: carbohydrate intake: ≤1g·kg-1 BW · d-1 for three days; CHO+: carbohydrate intake: ≥9g·kg-1 BW · d-1 for one day; and acuteCHO: 500ml juice sparkling water beverage.
Specifically, after a 10-min warm-up, subjects rested until reaching specified Larest. Subjects then carried out a 15s maximal sprint on a running track. Blood lactate was determined every minute until minute 10’ after the sprint.
A Friedman ANOVA with Dunn’s post hoc test was used to assess differences between conditions and time points. Statistical significance was accepted at p<0.05. Data are presented as mean ± standard deviation.
RESULTS:
νLa.max (mmol · L-1 · s-1) was 0.59 ± 0.09 in baseline, 0.51 ± 0.01 in lactate+, 0.53 ± 0.1 in CHO-, 0.54 ± 0.1 in CHO+ and 0.57 ± 0.1 in acuteCHO. Significant differences were observed between νLa.max values from baseline and lactate+ (p<0.001) and baseline and CHO- (p<0.05). The mean delta (∆) value, consisting of the difference between Larest and Lapeak (mmol · L-1), was 6.91 ± 1.0 in baseline, 5.99 ± 1.26 in lactate+, 6.15 ± 1.19 in CHO-, 6.32 ± 1.23 in CHO+ and 6.67 ± 1.25 in acuteCHO. Significant differences were identified between ∆baseline and ∆lactate+ (p<0.01), ∆baseline and ∆CHO- (p<0.05), as well as ∆baseline and ∆CHO+ (p<0.05).
CONCLUSION:
Variations in carbohydrate intake and Larest levels may lead to a reduction in net accumulated lactate levels in a νLa.max test. Therefore, careful consideration and adjustment of test methodology are necessary to avoid underestimating νLa.max in athletes.