31. BICARBONATE BEFORE HIT TRAINING BOOSTS TRAINING ADAPTATIONS

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When exercising at high intensity (above second threshold/FTP) a lot of hydrogen ions (H+) are produced in the working muscles. Without going to deep into the physiological mechanisms, H+ accumulation leads to to muscle fatigue and a decrease in performance. Bicarbonate (HCO3-) is a molecule acting as H+ buffer (reducing H+ concentration) both in the muscle and in the blood. For this reason, bicarbonate supplementation is widely used as an acute performance enhancer to ingest before/during competitions with efforts above the second threshold/FTP/critical power.

Interestingly, we have a study suggesting bicarbonate can also be used chronically (for weeks) before high intensity training sessions to boost physiological training adaptations and so, ultimately, performance in the race day. (1)

..How?

High Intensity Training (HIT) represents performing a workout with intervals above the the second threshold/FTP/critical power, so it generally leads to a net H+ accumulation. HIT is known to be a strong stimulus to induce aerobic physiological adaptations which benefits performance. In particular, it stimulates mitochondrial (the muscles’ powerhouses where energy is produced through the aerobic system) biogenesis and growth. This process is activated and powered by PGC-1α, a transcriptional coactivator factor. High intensity training triggers a lot of changes in the cellular muscular environment which globally activate PGC-1α and so the positive aerobic physio and performance adaptations. However, one of the environmental changes provoked, if taken alone, would inhibit PGC-1α: this is H+ accumulation! In fact, a previous study (2) showed that ingesting a H+ supplement before HIT sessions blunted the post-exercise response of PGC-1α!

So, while HIT globally induce positive mitochondrial adaptations, we could maximise its effects reducing the H+ net accumulation that is naturally associated with this training intensity. Here enter supplementing with bicarbonate (H+buffer) chronically (for weeks) before HIT.

Does chronic (for weeks) bicarbonate supplementation before high intensity training sessions boost training adaptations and so performance?

A study published by Edge and colleagues in 2006 on Journal of Applied Physiology can help to answer this question. (1)

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HOW DID THEY TRAIN?

• 16 recreationally active but not competitive cyclists female students were recruited.

• They were divided into two groups (BICARB s CONTROL) which for 8 weeks performed the same training schedule: 3 days/week of 6-12 x 2min at 140 –170% of second threshold.

• The only differences between the two groups was:

  • BICARB: ingested 0.4 g/kg of sodium bicarbonate ~1h before each HIT session (0.2 g/kg 90min before + 0.2 g/kg 30min before). For example, this dose represents 28g for a 70kg athlete.

  • CONTROL: ingested a placebo drink at the same timepoints