The purpose of this study was to examine the effects of sodium citrate (CIT) ingestion
on 30 km cycling performance. Eight trained male cyclists (VO2max = 54.7 ± 1.7 ml · kg-1 · min-1) performed two 30 km cycling time trials. The trials were double blind and randomly
assigned from CIT or placebo (PLC), with both dosages at 0.5 g kg body wt-1. Blood
samples were collected from an indwelling catheter at 10 km intervals and analyzed
for PO2, PCO2, pH, and lactate concentration ([La]). Power output, heart rate (HR) and RPE were
measured at 5 min intervals during the trials, while cycling performance was determined
from time to complete the 30 km. A repeated measures ANOVA and dependent t-tests were
used to locate differences between the trials. A significant difference (p ≤ 0.01)
was observed for pH and [La] during the trials with CIT being elevated above PLC throughout
the ride. No significant differences (p > 0.01) were observed for any of the other
dependent variables. However, power output and HR were slightly elevated during the
CIT trial. Performance time was significantly faster (p ≤ 0.05) for the CIT trial
(3459.6 ± 97.4 s) compared to the PLC trial (3562.3 ± 108.5 s). The data indicate
that favorable metabolic conditions were obtained following CIT ingestion and these
likely contributed to the improvement in cycling performance.
Key words
Buffer ingestion - endurance exercise - lactate - pH