Ventilatory Profile of Big Wave Surfers: An Exploratory Study ^†

Abstract

Big wave surfing, a high-risk sport involving rides on waves over 30 feet tall, exposes athletes to intense physical demands, particularly during wipeouts requiring extended breath-holding (apnea). Despite its growing popularity and professional status, the ventilatory profile of these elite athletes remains underexplored. This study is the first to examine the respiratory characteristics of Big Wave Surfers (BWS), focusing on lung function, respiratory muscle strength, and potential ventilatory adaptations or compromises. Findings suggest that BWS exhibit enhanced respiratory capacity, likely from apnea training and glossopharyngeal breathing, but also show signs of small airway obstruction, warranting further investigation and preventive health strategies.

1. Introduction

Big wave surfing is an extreme surfing discipline, defined by riding waves exceeding 30 feet (approximately 9 m) in height [1]. In big wave surfing, the physical demands escalate significantly, particularly during wipeouts, where athletes may be forced to hold their breath (apnea) for extended periods while subjected to strong underwater turbulence and pressure. To perform at an elite level, surfers must possess a combination of muscular endurance, upper-body strength, anaerobic power, and exceptional cardiorespiratory fitness [2]. Unlike most land-based athletes, surfers—especially in big wave surfing—are often submerged, exposed to cold water, and subjected to repeated apnea episodes. Therefore, it is plausible that their respiratory system adapts and presents superior lung capacities in ways similar to swimmers [3,4] or free divers [5,6]. Moreover, similarly to free-divers, before an apnea, Big Wave Surfers (BWS) also utilize Glossopharyngeal breathing (GPB) (or “frog breathing”) as a strategy to pack more air into their lungs after a deep breath, in order to increase their total lung capacity between 0.5 and 3 L [7,8], and increase residual lung volume and intra-thoracic pressure [9]. However, the long-term consequences of this technique are not yet entirely clear, and some risks associated with its continued practice (e.g., barotrauma; pulmonary hypertension) have been reported [4].

This study aims to examine the respiratory adaptations associated with big wave surfing and whether the physical stressors inherent to the sport lead to functional or structural pulmonary changes.

2. Materials and Methods

This is a cross-sectional, exploratory epidemiological study. The sample was composed of 17 professional big wave surfing athletes (18–52 years old), selected through convenience sampling. Inclusion criteria required individuals to have competed in at least one official national or international BWS competition. Exclusion criteria included having a current infection, chest discomfort, a history of serious pulmonary disease or thoracic injury such as rib fractures, or any musculoskeletal or pulmonary injury in the six months prior to the study. To minimize potential fatigue-related bias, all data were collected before any physical activity or surf sessions. Participant characterization was achieved through a structured questionnaire that gathered demographic information and details about their surfing practice. Anthropometric variables included height and body mass, which were measured using calibrated portable equipment. Pulmonary function in a forced maneuver was evaluated using a portable spirometer (MIR SPIROLAB II, MIR slr, Rome, Italy) following the guideline recommendations [10]. Respiratory muscle strength was assessed by measuring maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), using a MicroRPM (Vyaire Medical GmbH, Höchberg, Germany) pressure manometer. Participants were seated and used a nasal clip during testing. For MIP, subjects performed a slow and complete exhalation followed by a strong, rapid inhalation for at least 1.5 s. For MEP, after a maximal slow inhalation, they exhaled forcefully and quickly. Each of these measures was repeated 3 times with a minimum 1 min rest between trials, and tests were conducted in a temperature-controlled environment between 18° and 22 °C. For the statistical analysis the normality was assessed by the Kolmogorov–Smirnov test. Paired t-tests were applied to compare actual and predicted values for both spirometry and respiratory pressures. Multiple linear regression was used to identify significant correlations between variables such as age, years of surfing experience, and years of big wave surfing with pulmonary function measures. A significance level of p < 0.05 was adopted. All statistical analyses were performed using Microsoft Excel and IBM SPSS Statistics version 27.0.

3. Results

The 17 BWS athletes were male individuals (n = 14; 82.35%), with an average age of 33 ± 8.50 years. Their average surfing experience was 24.59 ± 7.53 years, and big wave surfing experience ranged from “less than 5 years” (n = 3; 17.64%), “6 to 7 years” (n = 4; 23.52%), to “more than 9 years” (n = 10; 58.82%). It is also evident that this sample is highly representative of the global elite, as all participants had competed in at least one big wave surfing competition, with 7 of them (41.17%) having participated more than seven times. Furthermore, the majority (n = 15; 82.35%) had already received BWS awards or award-nominations.

Table 1. Spirometry ventilatory parameters of Big Wave Surfers—mean and predicted values.

Variables	Scores	Predicted Scores	Predicted Scores (%)	p
FVC (L)	6.28 ± 1.42	4.68 ± 0.69	134.29 ± 21.92	<0.001 **
FEV1 (L)	4.73 ± 0.85	3.92 ± 0.56	120.94 ± 15.63	<0.001 **
FEV1/FVC (%)	76.19 ± 6.17	81.51 ± 1.43	93.47 ± 7.34	<0.001 **
PEF (L/s)	10.54 ± 2.26	9.10 ± 1.17	115.71 ± 18.53	0.002 *
FEF25–75% (L/s)	4.21 ± 0.77	4.55 ± 0.48	93.00 ± 16.95	0.044 *

Abbreviations: FVC: Forced Vital Capacity; FEV1: Forced Expiratory Volume in the first second; PEF: Peak Expiratory Flow; FEF_25–75%: Average Forced Expiratory Flow; * p < 0.05; ** p < 0.001.

shows the average values of the ventilatory parameters of BWS, as well as the predicted values. For muscle strength, analyzed by MIP and MEP, it is possible to verify in

Table 2. Maximum respiratory pressures (MRP) of Big Wave Surfers.

Variables	Score	Predicted Score	p
MIP (cmH2O) ♂ (n = 14) ♀ (n = 3)	138.35 ± 29.03 143.36 ± 25.72 114 ± 36.71	n.a. 106.85 ± 3.77 86.85 ± 2.88	n.a. <0.001 * 0.178
MEP (cmH2O) ♂ (n = 14) ♀ (n = 3)	143.88 ± 27.89 149.57 ± 23.69 117.33 ± 35.92	n.a. 147.38 ± 7.63 101.18 ± 4.06	n.a. 0.372 0.276

Abbreviations: MIP: maximum inspiratory pressure; MEP: maximum expiratory pressure; ♂: male; ♀: female; * p < 0.001; n.a.: not applicable.

that all values, despite being higher in relation to the predicted values, do not present a statistically significant difference, except for MIP in male BWS. No other statistically significant relationships were found between lung function parameters and variables such as age or years of practice (surfing and/or big wave surfing).

4. Discussion

There is increasing evidence that aquatic athletes—including swimmers, water polo players, and apnea divers—consistently show superior pulmonary function when compared to athletes from non-aquatic sports such as football or basketball [11,12]. Their lungs can withstand greater transpulmonary volumes and pressures than the average population, likely due to a combination of genetic predisposition and structural adaptations resulting from repeated pulmonary distension [8,12]. However, it is known that although water polo players exhibited elevated FEV₁ and FVC values, their FEV₁/FVC ratio was lower, possibly indicating either reduced ventilatory efficiency or greater functional residual capacity [12]. Likewise, spirometric findings in BWS reveal a mean FEV₁/FVC ratio of 76.19 ± 6.17%, bordering on the threshold for obstructive impairment. In addition, reduced FEF_25–75% values were found in 64.7% of BWS, suggesting potential small airway impairment, as observed in individuals performing lung packing or repeated glossopharyngeal insufflation (GPB) [13]. Big Wave Surfers also demonstrated significantly elevated maximal inspiratory (MIP = 138.35 ± 29.03 cmH₂O) and expiratory (MEP = 143.88 ± 27.89 cmH₂O) pressures when compared to untrained individuals (MIP = 115.29 ± 24.98 cmH₂O; MEP = 118.33 ± 23.5 cmH₂O) [12] and apnea divers (MIP = 131.30 ± 24.98 cmH₂O; MEP = 132 ± 30.01 cmH₂O) [5]. This is probably due to the fact that apnea training causes an increase in respiratory workload, since the hydrostatic forces to which the individual is subjected compress and deform the thorax, requiring the inspiratory muscles to counteract these forces, which leads to deeper inspirations and longer respiratory cycles. Apnea training causes an increase in respiratory workload, since the hydrostatic forces to which the individual is subjected compress and deform the thorax, requiring the inspiratory muscles to counteract these forces. This leads to deeper inspirations and longer respiratory cycles [14]. As for GPB, besides being an important training strategy to deal with hypoxic stress during apnea [15], it can lead to respiratory muscle dysfunction due to strenuous training and continuous demand on the respiratory muscles [4] and to a significant reduction in the elastic component of the lungs [7]. Given the repetitive and forceful nature of apnea during wipeouts, and the significant compressive forces experienced underwater, BWS may be at risk for chronic pulmonary changes. Therefore, further longitudinal studies are warranted to evaluate potential health risks, including obstructive lung disease, impaired diffusion capacity, and pulmonary hypertension, like those documented in divers [16]. Apnea training and accumulated years of exposure likely benefit BWS by inducing physiological adaptations that reduce CO₂ sensitivity and delay involuntary respiratory muscle contractions during breath-holding, thereby improving hypoxia tolerance. On the other hand, repeated apnea episodes and associated techniques like GPB may alter thoracic shape and the respiratory muscle mechanics, paralleling adaptations observed in chronic obstructive pulmonary disease. This ventilatory pattern may predispose BWS to decreased pulmonary compliance and increase the risk of barotrauma, pneumomediastinum, and chronic pulmonary dysfunction.

As an unstudied population, this research provides the first insights into the respiratory profile of BWS, addressing spirometric characterization and the identification of functional adaptations.

5. Conclusions

The athletes assessed exhibit enhanced respiratory function when compared to the general population, sharing several physiological features with swimmers and apnea divers, such as increased ventilatory capacity (FVC, PEF, MIP, and MEP). However, their FEV1/FVC ratio hovers around 70%, which may signal potential obstructive airway conditions, requiring further investigation.