*Article* **Effects of Acute Psychological and Physiological Stress on Rock Climbers**

**Pamela Villavicencio 1, Cristina Bravo 2,3,\*, Antoni Ibarz <sup>4</sup> and Silvia Solé 2,3**


**Abstract:** Background: The aim of this study was to assess the effects that psychological and physiological stressors have on indoor rock climbers, as well as to identify sex differences. Methods: 14 intermediate rock climbers participated in the study, 10 males and 4 females. Mean age was 31 ± 8 years for males and 21 ± 2 years for females. Day 1 consisted of test familiarization and baseline measurements. Day 2 included two test conditions, startle and fatigue, separated by 20 min. In the startle condition, participants had to lead climb a route, and a loud audio stimulus was presented near the top of the climb. In the fatigue condition, participants were required to climb as fast as they could until muscular failure. The competitive state anxiety inventory second review (CSAI-2R) questionnaire was used to assess somatic anxiety, cognitive anxiety, and self-confidence. The four-square step test (FSST) was used to assess motor control, and cortisol levels were acquired via passive drool (PD). Results: Cortisol concentrations were highest in the pre-startle condition (1.72 μg/dL ± 0.66), and values decreased post-startle (1.67 μg/dL ± 0.74) and post-fatigue (1.42 μg/dL ± 0.72). However, cortisol concentrations increased post-startle in females (1.57 μg/dL ± 0.96). Somatic anxiety in males was significantly higher post-startle (16.36 ± 5.54) than pre-startle (14.23 ± 5.09). Females had significantly higher somatic anxiety post-startle (18.00 ± 8.76), and they had lower self-confidence levels (30.00 ± 5.89) than males. Conclusions: There are differences in the way that males and females prepare and respond to stressful situations. Furthermore, time of day may have had a significant impact on cortisol concentrations.

**Keywords:** stress; cortisol; saliva; anxiety; rock climbers

#### **1. Introduction**

Rock climbing is a complex sport that encompasses both psychological and physiological stressors. Indoor rock climbing has two different climbing techniques: lead and top rope climbing [1,2]. In lead climbing, the climber must attend to the safety rope and clip it into anchors as they make their way up the route. If the climber does not clip the safety rope properly, they will generally fall a short distance. On the other hand, in top rope climbing, the safety rope passes through an anchor at the top of the climb, and the climber does not need to manage it. If a climber falls during a top rope climb, they will sag on the rope. Lead climbing has been associated with increased perceived stress because of the increased mental demand and consequence of falling [2]. However, this does not seem to be the case with advanced rock climbers [1].

When the body's homeostasis is disrupted, or perceived to be disrupted, the body initiates a stress response. This response includes the activation of the hypothalamic-pituitaryadrenal (HPA) axis [3]. The HPA axis starts with the secretion of corticotropin-releasing hormone (CRH) from the hypothalamus, followed by the release of adrenocorticotropic

**Citation:** Villavicencio, P.; Bravo, C.; Ibarz, A.; Solé, S. Effects of Acute Psychological and Physiological Stress on Rock Climbers. *J. Clin. Med.* **2021**, *10*, 5013. https://doi.org/ 10.3390/jcm10215013

Academic Editor: Władysław Jagiełło

Received: 20 August 2021 Accepted: 27 October 2021 Published: 28 October 2021

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hormone (ACTH) from the pituitary gland, and finally the release of glucocorticoids from the adrenal glands. Since cortisol can be used as a biological marker of stress, several studies have measured it either via plasma or salivary samples [2,4,5]. The gold standard for salivary cortisol sampling is the passive drool (PD) method, since the effect of flow rate on saliva composition can be discarded [6].

Rock climbing can quickly induce stress due to the fear and anxiety of falling, as well as the elevated cognitive attention it requires to plan movement sequences, recovery positions, speed of the climb, and timing of clipping the safety rope [2]. The amount of perceived stress can also be influenced by the level of expertise of the climber and whether others are present [7,8]. Studies have found that altering the climbing technique to lead climbing increased both subjective anxiety and plasma cortisol concentrations [2]. The peak plasma cortisol concentration is suggested to occur 15–20 min after the stressor, regardless of the climbing technique [1,5,9]. However, one study found that post-climb salivary concentrations were higher immediately after the climb and not 15 min later [10].

Stress can also influence motor skills. Some studies have found that stress can disrupt the accuracy and coordination of movements, as well as posture [11]. Stress also affects the speed of movement in the fight-or-flight response, causing movements to be quicker at the expense of accuracy [11]. These frantic movements lead to decreased success rates, likely because of altered sensory feedback from the lack of haptic feedback [11]. In stressful situations, there may also be impaired cognitive and visuomotor processes that negatively affect motor skills [11].

When this article was published, there was limited data on the role that stress plays in rock climbers, and even more limited literature on differences between sexes. The purpose of this study was to determine the implications that stress has on motor control and cortisol levels in rock climbers and to bridge the gap between psychological and physiological findings. Our hypothesis is that motor control, measured via dynamic balance and coordination with the four-square step test (FSST), will decrease and that cortisol levels will increase, as has been shown in previous studies [2,10].

#### **2. Materials and Methods**

### *2.1. Participants*

A total of 14 participants volunteered to take part in the study, 10 males and 4 females. Mean age, height, and body mass for males was 31 ± 8 years, 176 cm ± 5, and 70 kg ± 6.5, respectively. Mean age, height, and body mass for females was 21 ± 2 years, 166 cm ± 5, and 59 kg ± 2.9, respectively. Participant information is reported in Tables 1 and 2. The study took place at an indoor rock-climbing gym. All participants were intermediate climbers, with a minimum skill level of 6c. They had no injuries or underlying medical conditions and had low to moderate stress levels, as measured by the Perceived Stress Scale (PSS) [12]. Participants completed an informed consent form after a thorough explanation of the study and after completing a physical activity readiness questionnaire (PAR-Q) [13].


**Table 1.** Male participant information.


**Table 2.** Female participant information.

#### *2.2. Competitive State Anxiety Inventory Second Review (CSAI-2R) Questionnaire*

The CSAI-2R consists of 17 items that are scored on a Likert scale from 1 to 4, and the combined scores result in a final score on each of the 3 subscales (somatic anxiety, cognitive anxiety, and self-confidence). The European Spanish version of the CSAI-2R consists of 18 items [14].
