Physiological Dynamic Apnea Responses in Relation to Apnea Capacity in Triathletes

Abstract

The aim was to assess the cardiac, arterial oxygen saturation, lactate, hormonal and Borg rating of perceived exertion (RPE) responses to acute apnea in relation to apnea capacity in 18 middle-aged triathletes. Subjects were monitored while swimming two 50-m freestyle exercise trials with fins at maximal speed: with normal frequency breathing (NB) and with complete apnea (Ap); the latter was used to assess apnea capacity. The subjects with significant alteration in swimming performance inducing a time increase greater than 2.5% during Ap vs. NB were put in the group: bad apnea capacity (Bad Ap); the others, who showed no significant alteration in performance, were put in the group: Good Ap. Under apnea, both groups showed a decrease in arterial oxygen saturation (p<0.05). In Ap conditions, only Bad Ap had a significant lower maximal heart rate vs. NB (p<0.05), with lower blood lactate (p<0.05) and arm stroke frequency (p<0.01). No change in saliva hormonal concentrations was found during the experiment for both groups, whereas RPE responses were increased in the Good Ap group under Ap vs. NB conditions. In conclusion, a good apnea capacity seems to be associated with lower cardiovascular and metabolic apnea alterations in middle-aged recreationally-trained triathletes.

Short-term Dehydroepiandrosterone Intake and Supramaximal Exercise in Young Recreationally-trained Women

“…It should be noted that the RAST did not elicit any change in steroid hormone concentrations from the resting values in our recreationally trained females, irrespective of the treatment administered. This finding is partially discrepant with previous studies using supramaximal exercise in the laboratory and on the field [11,32,33], but it might be suggested that the RAST was too short ( < 40 s) to induce significant modifications in cortisol and DHEA [15,22], and it should be recalled that the exercise induced-increase in testosterone only occurred in male subjects [33]. It is also interesting to note that post-RAST testosterone under DHEA treatment was significantly decreased compared with pre-RAST values by about 20 %, probably reflecting the change in blood flow induced by exercise.…”

Underwater and Surface Swimming Parameters Reflect Performance Level in Elite Swimmers

“…Apnea induces a typical cardiovascular response called a diving response, such as bradycardia (Foster and Sheel, 2005), which can compete with exercise tachycardia (Wein et al, 2007;Alboni et al, 2011) during the underwater apnea stages. If some swimming studies have focused on the physiological repercussions of apnea (vs. breathing) in a situation of surface swimming (Guimard et al, 2014(Guimard et al, , 2017(Guimard et al, , 2018, to our knowledge, one study has considered the underwater physiological aspects but without determining the influence of the non-swimming phases (Rozi et al, 2018).…”

Effects of Extended Underwater Sections on the Physiological and Biomechanical Parameters of Competitive Swimmers

“…It could happen that bradycardia occurring during extended underwater sections may be counterbalanced by a bigger increase in heart rate after the underwater part, leading to similar heart rate values at the end of the effort. Only if checking the instantaneous heart rate during efforts, as previous studies have done for artistic swimming (Rodríguez-Zamora et al, 2012) and surface swimming (Guimard et al, 2014(Guimard et al, , 2017(Guimard et al, , 2018, could it be possible to draw solid conclusions about this. Also, another factor that could hinder conclusions is the large individual variability observed in the bradycardia response to apnea, as found in the study by Lindholm et al (2002).…”

“…It is interesting to note that previous studies on swimming have shown that the expected bradycardia was only observed in athletes unable to maintain their performance in apnea conditions (referred to as "with a bad apnea capacity") during either 4 × 25 m (Guimard et al, 2014) or 50 m with fins (Guimard et al, 2017). Considering the high level of the swimmers, the present study was probably carried out by athletes "with a good apnea capacity" (Guimard et al, 2017), capable of maintaining an optimal cardiac output under conditions of intense dynamic apnea and thus their performance. Indeed, this could be confirmed by the similar relative decrease in underwater parameters lap to lap regardless of the longer apnea times requested (Figure 3).…”

“…The decrease in heart rate can vary from 15 to 40%, but a small proportion of healthy individuals can develop bradycardia up to 20 beats per minute (Alboni et al, 2011). It is interesting to note that previous studies on swimming have shown that the expected bradycardia was only observed in athletes unable to maintain their performance in apnea conditions (referred to as "with a bad apnea capacity") during either 4 × 25 m (Guimard et al, 2014) or 50 m with fins (Guimard et al, 2017). Considering the high level of the swimmers, the present study was probably carried out by athletes "with a good apnea capacity" (Guimard et al, 2017), capable of maintaining an optimal cardiac output under conditions of intense dynamic apnea and thus their performance.…”