Introduction

Relative Energy Deficiency in Sport (RED-S) expands upon the concept of the Female Athlete Triad [1]. RED-S recognises that male and female athletes can suffer from the effects of low energy availability, incorporating multi-dimensional symptoms including disruptions in cardiovascular, gastrointestinal, musculoskeletal, haematological, metabolic, endocrine, immunological and psychological function [1]. It is estimated that 70% of elite athletes suffer with ≥1 symptom of RED-S [2, 3]. This high prevalence is of great concern and may impact athletes’ physical and psychological health. An Australian study of elite and pre-elite female athletes found that 80% demonstrated at least one sign of RED-S and one-third of athletes had signs of mental illness [3]. RED-S can go unrecognised and athletes may not receive appropriate education or management [4]. To improve awareness and understanding of RED-S, research exploring the physical and psychosocial impact from the personal perspective of athletes is needed.

Individuals participating in weight-dependent sports, such as lightweight rowing, have a high-risk of developing RED-S due to weight restrictions. Lightweight rowers are required to weigh in 2 hours before racing, with eligibility for summer international competitions requiring men to weigh ≤70kg and women ≤57kg. To achieve weight, athletes use weight loss tactics such as restricting calorie intake, excessive exercise, and increasing sweat loss. Such tactics may increase the risk of developing RED-S symptoms due to increased energy expenditure coupled with low calorie intake [5]. The prevalence and impact of RED-S within this at-risk population is poorly understood and many athletes are unaware of long-term effects [6]. This study aimed to investigate the physical and psychosocial impact of RED-S from the personal perspective of lightweight rowers.

Methods

This study is reported in accordance with the Consolidated Criteria for Reporting Qualitative Studies (COREQ) guidelines [7] and has been approved by the University of Oxford Medical Sciences Interdivisional Research Ethics Committee (ethics ref: R67265/RE001).

This qualitative study had two overarching aims, however the results for each aim will be reported separately due to depth of responses and manuscript length restrictions. The first aim ‘investigating the physical and psychosocial impact of RED-S from the personal perspective of lightweight rowers’ is addressed in this manuscript. The second aim, ‘investigating knowledge, awareness, and management of RED-S in lightweight rowers and physiotherapists working in lightweight rowing’ is addressed in a subsequent manuscript [4].

A sample of convenience was used to recruit participants via the social media platform Twitter. For participant eligibility, individuals adhered to the following criteria: 1) aged ≥18 years; 2) current or former lightweight rowers from the UK at elite-intermediate level for ≥1 year; 3) self-reported having experienced ≥1 symptom of RED-S whilst participating in lightweight rowing (i.e. recurrent injuries including stress fractures, menstrual dysfunction, low energy levels, prioritised leanness (low body mass taking priority over demands of sport), excessive fatigue, muscle loss, inability to recover between sessions, diagnosis of RED-S or the Female Athlete Triad) [8]. Recruitment posters outlined eligibility criteria and participant eligibility was confirmed via email before a telephone interview was arranged.

Interviews were conducted by one author (LG), a female physiotherapist with four years’ experience competing as an elite lightweight rower. The interviewer had no established relationship with participants prior to interviewing. A semi-structured interview guide was developed in partnership with the target population (lightweight rowers and physiotherapists), and study materials were piloted on two lightweight rowers and two physiotherapists. The semi-structured interview guide contained primarily open-ended questions with relevant prompts to elicit in-depth responses.

One telephone interview per participant was required: duration ranging between 32–60 minutes. A study journal was used, summarising each interview, and allowing reflection of initial thoughts. All interviews were audio-recorded and transcribed verbatim by the interviewer (LG), informed verbal consent was obtained at the start of the interview. Pseudonymisation was used during transcription and an alias was aligned to each participant.

An inductive analysis approach was used; themes were derived from the data, rather than pre-conceptions or theoretical frameworks. Participants’ ‘competition level’ was based on competition category: elite international (top level competition against different countries); elite national (top level competition within the U.K); intermediate (local and national competition racing as an intermediate) [9]. The interviewer (LG) read the transcripts multiple times, with and without the accompanying audio-recording, identifying minor/major themes and similarities/differences between participants’ experiences. NVivo V.11 software facilitated coding of the transcripts into broad-inclusive categories, generating themes/subthemes of relevance to the study aim, whilst refining for analysis. Codes were sorted into hierarchical structure; overlapping codes were merged and codes unrelated to the study aim were filed elsewhere. A second author, experienced in qualitative research (SF) reviewed the data, coding structure and preliminary themes in NVivo V.11 ensuring accurate representation of the dataset, after which a meeting was held to finalise the coding consensus.

Results

Participant characteristics

Participants were aged a mean 22 years (range 19 to 32) and 8 (67%) were female (Table 1). Six participants had competed in lightweight rowing at an Olympic or international level (50%), two had competed at a national level (17%), and three had competed at an intermediate level (25%). The length of participation in lightweight rowing competitions ranged from 1 to 8 years. Five participants had retired from rowing completely (42%), four were previous lightweight rowers who were rowing as a heavyweight at the time of interview (33%) and three participants (25%) still competed as lightweight rowers at the time of interview.

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Table 1. Participant characteristics.

https://doi.org/10.1371/journal.pone.0265268.t001

Summary of key themes

All lightweight athletes described restricting calorie intake whilst increasing energy expenditure through excessive exercise and/or weight-loss tactics, prior to weighing in. These practices resulted in a range of physical and psychosocial implications (Fig 1).

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Fig 1. Summary of findings.

https://doi.org/10.1371/journal.pone.0265268.g001

Psychosocial implications

Six themes were identified demonstrating the psychosocial implications of RED-S in light-weight rowers, additional quotations are presented for each theme in Table 2.

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Table 2. Additional quotations illustrating the key themes.

https://doi.org/10.1371/journal.pone.0265268.t002

Low mood and poor emotional regulation.

Many participants described experiencing low mood and poor emotional regulation. They felt that hunger and dieting had a negative impact on their mood and ability to regulate emotions.

MIA: ‘I remember I had a driving lesson and I just cried because I was just so flat and really down and I can now look back on it now as something chemically not right because of not eating… I had cake once because it was my birthday and my mood just changed drastically.’

(Age 19–21, former lightweight, elite national)

Discussion

In this study, lightweight rowers did not meet their energy needs due to high energy expenditure and restricted calorie intake, which negatively impacted their psychosocial and physical health. To our knowledge, this is the first study to explore experiences of RED-S from the perspective of lightweight rowers. These findings are supported by previous research highlighting a need for effective strategies to prevent and manage RED-S whilst improving education and support for athletes.

Energy intake must align with energy expenditure to maintain adequate physiological function, growth and repair of tissue, and to prevent illness [10]. Lightweight rowers in this study used weight loss tactics and experienced a ‘yo-yo’ effect of weight fluctuation. Weight-class sports and leanness sports are associated with an increased risk of athletes using extreme weight-loss tactics and experiencing rapid weight fluctuation, which can be detrimental to health and performance [11]. Individuals in this study felt lightweight rowing negatively affected their relationship with food, and this relationship with food often persisted once retired. Daily calorie counting can increase the risk of developing disordered eating [12]. Disordered eating among lightweight rowers is not a new phenomenon; a higher prevalence of disordered eating has been reported among collegiate lightweight rowers compared with heavyweight rowers [13]. Furthermore, of 103 elite heavyweight and lightweight rowers, the lightweights were more likely to have disordered eating, depression, confusion, and tension [14]. Disordered eating can negatively impact upon health; adversely affecting gastrointestinal, endocrine, hematologic, neurologic, bone metabolism, pulmonary and cardiac function [15], which aligns with our study findings. A qualitative study in endurance runners found that athletes’ experiences of RED-S were similar to the physical and psychological experiences expressed by lightweight rowers in our study [16]. In contrast, comparison of findings between studies suggests that the mechanisms influencing the onset of RED-S may in some cases, be sport-specific. Therefore, RED-S prevention strategies may benefit from being sport-specific and addressing specific challenges faced within a sport. Our findings emphasise the importance of awareness and education of RED-S and the associated serious health consequences.

Lightweight rowers described negative implications on their social life and relationships due to rowing, but accepted this as ‘just a sacrifice you have to make.’ Such beliefs may reduce athletes’ communication with coaches and the sports medicine team about psychosocial health, inhibiting adequate management. Aerobic exercise can increase cognitive function including memory and executive functions [17], however, nutrient deficiencies are associated with reduced productivity and depressive symptoms in school-aged children [18], aligning with the lightweight rowers in this study who experienced difficulty concentrating, low energy levels and mood swings. Additionally, negative experiences as a lightweight rower may affect physical activity levels across the lifespan. Ten participants reported a negative relationship with exercise due to lightweight rowing and excessive training which made them less inclined to participate in exercise after retirement. A survey that asked 293 individuals about past sport participation, revealed those who had negative memories or experiences during sport were more likely to cease participation in sport or physical activity in later life due to such experiences [19]. Maintaining a physically active lifestyle across the lifespan plays an important role in sustaining adequate physical and mental health, highlighting the importance of promoting positive experiences in sport. If lightweight rowers have negative experiences due to dieting, excessive exercise, and weight loss, it may make them less inclined to continue with physical activity once retired from lightweight rowing.

Lightweight rowers in this study described difficulties sleeping, resulting in physical and psychological consequences. Sleep has numerous vital physical and psychological functions for humans, and is one of the most crucial contributions to successful athletic performance [20]. Sleep can increase vigour, learning ability, and mood [20]. Insufficient sleep can negatively impact athlete’s performances due to fatigue, reducing metabolism, endocrine function, cognition, immunity, pain perception and inflammation [20]. Thus, impaired sleep in lightweight rowers may contribute to other findings including recurrent injury and illness, fatigue, low mood, poor concentration, and reduced performance.

This study had a number of limitations and strengths. The interviewer’s personal experience with RED-S enabled a strong rapport with participants, facilitating in-depth responses. However, the personal experiences of the interviewer may have biased interpretation of findings. Participants provided thorough responses, however a limitation of this study is that some information may not be disclosed due to the sensitivity and stigma attached to RED-S. By interviewing lightweight rowers of a range of competition standards and both sexes, the generalisability of findings is increased, but not to a wider population outside the UK. Additionally, our study was not designed to explore differences in RED-S experiences between male and female athletes, or between athletes competing at different competition levels. This could be a fruitful area for future research. Conducting telephone interviews rather than face-to-face interviews reduces response bias, whilst increasing validity with potentially resulting in more honest answers as there is no fear of judgment [21]. Using Twitter for recruitment relied upon participants having social media; potentially leading to selection bias and reducing generalisability. Nevertheless, social media provides a practical and efficient way of recruiting. Former lightweight rowers reflected upon past experiences, potentially resulting in recall bias but providing important insights into the long-term impact of RED-S.

Conclusion

Restricting calorie intake whilst increasing energy expenditure to ‘make weight’ had significant physical and psychosocial implications for lightweight rowers. The physical impacts of RED-S included disrupted sleep, fatigue, decreased performance, impaired recovery, bowel disruption, menstrual dysfunction, weakened immune system, musculoskeletal pain, and injuries. The psychosocial impacts included low mood, poor emotional regulation, reduced social interaction, difficulty maintaining relationships, poor concentration, guilt and anxiety around food, disordered eating, and negative body image. These findings highlight the importance of effective strategies to prevent and manage RED-S in lightweight rowers.

Acknowledgments

The authors would like to thank the study participants for volunteering their time. The study was designed by LG, MM and SF; data were collected and analysed by LG and SF; data interpretation and manuscript preparation were undertaken by LG, MM and SF. All authors approved the final version of the paper.