Blood Lactate Accumulation During Competitive Freediving and Synchronized Swimming
Authors: Lara Rodríguez-Zamora, Harald K. Engan, Angelica Lodin-Sundström, Fanny Schagatay, Xavier Iglesias, Ferran A. Rodríguez, Erika Schagatay
DOI / Source: https://pubmed.ncbi.nlm.nih.gov/29571233/
Date: January 2018
Reading level: Intermediate
Why This Matters for Freedivers
This study shows, with real competition data, that many freediving disciplines rely heavily on anaerobic energy (lactate production), not just “oxygen efficiency.” It helps explain why some sessions feel brutally fatiguing even if your technique is good, and why different disciplines (especially depth vs pool vs static) can leave very different “after-effects” in the body.
Synopsis
Freediving is often described as a calm, oxygen-saving sport—but competition performances can be surprisingly “anaerobic.” This paper measured blood lactate changes during real events in competitive freediving and synchronized swimming to see how much anaerobic metabolism is involved across disciplines.
The researchers took capillary blood lactate samples right before competition attempts and again three minutes after. They calculated net lactate accumulation (NLA)—how much lactate increased because of the performance. They included six freediving disciplines (STA, DYN, DNF, CWT, CNF, FIM) and three synchronized swimming disciplines (solo, duet, team), using elite athletes competing at high level.
The pattern was clear: every discipline produced lactate, meaning anaerobic metabolism is part of essentially all apneic competition events. But the size of the lactate response depended strongly on what kind of work was done and how long the apnea lasted. Static apnea produced the lowest lactate rise (very little muscle work, even though the apnea is long). The largest lactate rises were seen in depth disciplines, especially constant weight no fins (CNF) and constant weight (CWT)—disciplines that combine long apnea with heavy whole-body work (particularly the hard ascent). Synchronized swimming also produced substantial lactate, but generally less than freediving depth disciplines, likely because swimmers have brief breathing moments between underwater sections that partially reduce the anaerobic load.
A useful takeaway is that apnea duration matters, but muscle mass and intensity matter even more: long breath-holds without big muscle work (static) don’t spike lactate much, while demanding full-body work under apnea does. Practically, this helps freedivers understand why CNF/CWT training can feel so “acidic” and exhausting, why recovery can take longer than expected, and why designing training needs to respect the very different metabolic stress of each discipline.
Abstract
A number of competitive water sports are performed while breath-holding (apnea). Such performances put large demands on the anaerobic system, but the study of lactate accumulation in apneic sports is limited. We therefore aimed to determine and compare the net lactate accumulation (NLA) during competition events in six disciplines of competitive freediving (FD) and three disciplines of synchronized swimming (SSW). The FD disciplines were: static apnea (STA), dynamic apnea (DYN), dynamic apnea no fins (DNF), constant weight (CWT), constant weight no fins (CNF), and free immersion (FIM). The SSW disciplines were solo, duet and team. Capillary blood lactate concentration was measured before and three minutes after competition performances, and apneic duration and performance variables were recorded.
In all nine disciplines NLA was observed. The highest mean NLA (mmol·L⁻¹) was found in CNF at 6.3, followed by CWT at 5.9 and SSW solo at 5.0. STA showed the lowest NLA at 0.7 mmol·L⁻¹ compared to all other disciplines. The NLA recorded shows that sports involving apnea involve high levels of anaerobic activity. The highest NLA was related to both work done by large muscle groups and long apneic periods, suggesting that NLA is influenced by both the type of work and apnea duration, with lower NLA in SSW due to shorter apneic episodes with intermittent breathing.