Does Sodium Citrate Cause the Same Ergogenic Effect As Sodium Bicarbonate on Swimming Performance?

Area of Science:

• Sports Science
• Exercise Physiology
• Biochemistry

Background:

• High-intensity exercise performance is often limited by acidosis.
• Alkaline buffers like sodium bicarbonate (SB) and sodium citrate (SC) are investigated for ergogenic potential.
• Optimal timing for buffer ingestion remains a key consideration for maximizing performance benefits.

Purpose of the Study:

• To examine the effects of sodium bicarbonate (SB) and sodium citrate (SC) ingestion on 400m swimming performance.
• To analyze blood responses, including pH, bicarbonate, and base excess, following SB and SC supplementation.
• To determine the ergogenic potential and optimal timing of SB and SC for high-intensity swimming.

Main Methods:

• A double-blind, placebo-controlled crossover trial involving six elite male swimmers.
• Participants ingested SB (0.3 g·kg-1), SC (0.3 g·kg-1), or a placebo 90 minutes before a 400m maximal freestyle swim.
• Blood samples were collected at rest, 60 minutes post-ingestion, immediately post-exercise, and 15 minutes post-exercise to measure acid-base status.

Main Results:

• SB ingestion significantly elevated blood pH, bicarbonate, and base excess before the test compared to baseline.
• SC ingestion did not significantly alter blood acid-base parameters.
• SB supplementation improved 400m swimming performance by 0.6% in 5 out of 6 participants, while SC decreased performance by 0.2%.

Conclusions:

• Sodium bicarbonate (SB) demonstrates a modest ergogenic effect for single bouts of high-intensity swimming, likely due to enhanced blood alkalosis.
• Sodium citrate (SC) provides minimal to no ergogenic benefit and may even slightly impair performance.
• Individualizing SB ingestion timing based on the peak rise in alkalosis could optimize its performance-enhancing effects.