The influence of females wearing a triathlon wetsuit on resting blood pressure

Mercer, JA FACSM, Soucy, M, Queen, R, Ciulei, M., & Prado, ADepartment of Kinesiology and Nutrition Sciences, University of Nevada, Las Vegas

INTRODUCTION

Triathlon is an endurance event that combines swimming, running and cycling. The sport has increased participation and there has also been an increase in triathlon-related deaths (USAT 2013). USA Triathlon (2013) has reported that between 2003 and 2011 there have been 44 participant deaths at USAT sanctioned events, with 31 taking place during the swim portion.

Wetsuits are commonly used during the swim portion of triathlons to enhance both performance and thermoregulation. Blood pressure is a simple, noninvasive measure and can be a risk factor for sudden cardiac death. It is not known if wearing a wetsuit influences blood pressure. Previous work has tested the influence of wetsuit on blood pressure in males (Prado, thesis) but no data exist for females.

ABSTRACTOf the deaths that have occurred during a triathlon event, the vast majority have come during the swim segment (United States Triathlon Association 2012 report). The mechanism behind these deaths is unclear, but wearing a wetsuit may play a role. PURPOSE: To determine if resting blood pressure is influenced by wearing a wetsuit and/or wetsuit size. METHODS: Subjects (n=8 females; 33.0±8.2 years, 162.0±5.0 cm, 59.3±5.1 kg) that were able to fit into two of four available wetsuits based upon manufacturer sizing criteria volunteered to participate. Resting systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured at 1-min, 3-min, and 5-min marks while Standing and lying Prone during three resting conditions (each lasting 5-mins): No wetsuit (NWS), the smallest wetsuit (SWS), and largest wetsuit (LWS) (within manufacturer guidelines). Blood pressure recordings were averaged across the three measurements for each condition. Dependent variables (SBP, DBP) were analyzed using a 2 (position: Standing, Prone) x 3 (condition: NWS, SWS, LWS) repeated measures analysis of variance (α= 0.05). RESULTS: Neither SBP nor DBP were influenced by the interaction of position and condition (p>0.05). DBP was not influenced by position (p>0.05) or condition (p>0.05). SBP was influenced by both position (p<0.05) and condition (p<0.05). Specifically, SBP was greater during Standing wearing SWS (121.0±14.2 mmHg) vs. NWS (110.9±8.9 mmHg) as well as during Prone [SWS 124.2±10.0 mmHg; NWS 118.4±12.4 mmHg)] (p<0.05). Additionally, SBP was greater during Prone position wearing LWS (123.5±10.8 mmHg) vs. NWS (118.4±12.4 mmHg) (p<0.05). CONCLUSION: Wearing a wetsuit did increase SBP, especially while wearing a smaller sized wetsuit. Although it is not known if the 4-9% increase in SBP has any negative physiological influence, it does seem reasonable for persons diagnosed with hypertension to consider carefully the influence a wetsuit size has on blood pressure.

METHODS

Subjects: The abstract included n=8; the poster includes n=12 Female adults (n = 12; 29±8.7 yrs; 162±4.7 cm; 60.3±6.0 kg)

Instrumentation: Wetsuit: HUUB Design Limited, sizes - S, M, ML, L Blood pressure cuff: Omron 7 series wrist blood pressure monitor

(Omron, Kyoto, Japan) Heart rate monitor: Polar RS800CX

Procedures: 3 standing conditions (NWS, SWS,LWS):

3 BP measurements over 5-mins (t= 100sec, intervals) 3 Prone laying conditions (NW,SW,LW)

3 BP measurements over 5-mins (t= 100sec, intervals) Data Reduction:

SBP: average systolic blood pressure taken per condition. DBP: average diastolic blood pressure taken per condition.

RESULTS

Neither Systolic or Diastolic BP were influenced by the interaction of Wetsuit Size and Position (Figures 1 and 2; p=0.457).  SBP was influenced by condition (p=0.006) but not position (p=0.087). DBP was not influenced by Wetsuit condition (p=0.100) or position (p=0.751).

SBP was greater while wearing either wetsuit vs. NWS while standing (p<0.05). SBP was not different between any conditions while prone.

ACKNOWLEDGEMENT

Partial funding provided by Nevada INBRE which is funded by grants from the National Center for Research Resources (5P20RR016464-11) and the National Institute of General Medical Sciences (8 P20 GM103440-11) from the National Institutes of Health.

PURPOSE

To determine if resting blood pressure is influenced by wearing a triathlon wetsuit as well as body position. Furthermore, the influence of wetsuit size on blood pressure was tested.

Figure 2: Means and standard error for SBP while not wearing a wetsuit (NWS), wearing a small sized wetsuit (SWS), or large sized wetsuit (LWS) while either standing or prone position. Note: * indicates different compared to NWS.

Figure 3: Means and standard error for diastolic blood pressure while not wearing a wetsuit (NWS), wearing a small sized wetsuit (SWS), or large sized wetsuit (LWS) while either standing or prone position. Diastolic blood pressure was not influenced by either wetsuit condition or position (p>0.05).

CONCLUSION

In this study of females, wetsuit size had no influence on SBP. Interestingly, males are at greater risk of death during a triathlon than females. It may be that the wetsuit design for females does not negatively influence blood pressure.

Figure 1: %difference in SBP for each participant. A greater value indicates increased BP vs. NWS.