Increased resting lactate levels and reduced carbohydrate intake cause νLa.max underestimation by reducing netlactate accumulation—A pilot study in young adults

Modulation of testing conditions such as resting lactate (La rest) levels or carbohy-drate intake may affect the calculation of the maximal glycolytic rate (νLa.max).To evaluate the impact of elevated La rest as well as reduced and increased carbo-hydrate availability on νLa.max in running sprints (RST), twenty- one participantscompleted five 15-s RST tests on a running track under five different conditions:(I). baseline: La rest ≤1.5 mmol·L−1; (II). Lactate+: La rest ≥2.5 mmol·L−1; (III).CHO−: carbohydrate intake: ≤ 1 g·kg −1 BW d −1 for 3 days; (IV). CHO+: carbohy-drate intake: ≥ 9 g·kg−1 BW d −1 for one day; and (V). acuteCHO: 500 mL glucosecontaining beverage consumed before RST. νLa.max was significantly reduced inlactate+ and CHO− conditions compared to the baseline RST, due to a reductionin the arithmetic mean delta (∆) between La peak and La rest lactate concentration(Lapeak, mmol · L−1). AcuteCHO led to an increase in Larest compared to baseline,CHO− and CHO+ with a high interindividual variability but did not significantlyreduce νLa.max. Therefore, avoiding low carbohydrate nutrition before