The effect swimming training intensity has on sleep, mood and recovery in elite swimmers

Pretorius, Shandré
Journal Title
Journal ISSN
Volume Title
BACKGROUND: Swimming is dynamic in nature and utilises both anaerobic and aerobic energy systems, and is a sport in which elite athletes often reach their peak physiological performance. Recovery has been found to encompass five factors; sleep, nutrition and hydration, psychological and emotional state, and active cooldown. Sleep forms one of the main components and if an athlete has poor sleep quality and quantity it may have a negative cascading effect on the physiology involved in the recovery process. Sleep quality and the components of the Total Quality Recovery (TQR) score are all interlinked and dependent on each other in the cycle of recovery. When an individual has slept for 8 hours and is in a positive mood during training and competitions the swimmers performance improves. Although recovery measures have been studied in elite swimmers, quantifying each factor at an individual level by using the TQR, mood and sleep measures will add to the knowledge of optimising swimmers performance. OBJECTIVE: To determine the effect swimming training intensity has on elite swimmers by assessing sleep, mood, performance and recovery. METHODS: A quantitative, explorative analytical study was conducted to assess the effect that swimming training intensity has on sleep, mood, performance and recovery in 15 elite swimmers between the ages of 13-21 years with a mean age of 16±2.09 years. Individuals were required to wear a Fitbit™ device on their non-dominant wrist for the duration of the 14 week study to measure daily calories expenditure, steps, active minutes, distance walked , total sleep time (TST), restless minutes, rapid eye movement (REM), none rapid eye movement (NREM), light and deep sleep, exercise and resting heart rate (RHR). In addition they completed the following questionnaires daily- Total Quality recovery (TQR) and Sleep Diary (SD), and weekly the Wellness Questionnaire and the Profile of Mood States (POMS). The Pittsburg Sleep Quality Index (PSQI), Sleep Hygiene Index (SHI) and Morningness-Eveningness Questionnaire (MEQ) were completed every four weeks and lastly the Sports Emotional Questionnaire (SEQ) was only completed when the athlete swam in an event. Participants completed self-reported questionnaires and Fitbit data was automatically collected. All data was collected by the researcher on a weekly basis. Statistical analysis was performed using Statistica version 10. The v demographics were expressed as mean, median and interquartile ranges and descriptive analysis was used to describe the interrelationships of the PSQI, SHI, MEQ, SD, TQR, training intensity and performance, in order to illustrate the relationship between sleep, performance, mood and recovery. A pilot study on 8 participants was conducted using a similar methodology used to optimise the main study, and in the main study the same model Fitbit in addition to a different model was used in the latter part: hence the two studies are analysed and reported separately. RESULTS: 15 participants were included in the final analysis of the main study; with the mean age of participants 16±1.81 years with competitive swimming years mean of 6.7±2.71 years. Data analysis in the pilot study was performed on 8 participants, with a mean age of 16±2.78 years and mean of 6.5±3.33 years of competitive swimming. DROPOUT RATE: 11.76% drop out of participants was observed with 2 participants being excluded from the main study due to incomplete data. In the pilot study there was a dropout rate of 46.67% with 7 participants being excluded. SLEEP: A 52% and 13% decrease in FB TST was found in the main and pilot study. A steadily increase in sleep efficiency was observed in the main (60%) and pilot (46%) studies. SD TST compared to FB TST in the main (p=0.006) and pilot (p=0.03) study. MOOD: A progressive increase in depression and decrease in vigour was observed in the main (5%; 4%) and pilot (6%; 5%) studies. Participants experienced a pleasant mood state throughout the duration of the main and pilot studies. PERFORMANCE: An average RHR of 63.43 beats per minute (bpm) was found in the main study. Performance times during training and competitions improved in the main (1.345 seconds; 0.04 seconds) and pilot (3.545 seconds; 7.465 seconds) study. RECOVERY: Each TQR component fluctuated during the main and pilot studies. The only component that remained relatively steady in the pilot study was water consumption. CONCLUSION: It was found that TQR recovery directly reflected a swimmers’ performance, during training cycles with changes in training intensity. A strong assumption can be made that the sleep and mood factors can influence performance through recovery. This study could effectively link aspects of sleep quality and quantity to recovery and that mood had an effect on performance during training and competitions. Therefore, this study was able to find a relationship between sleep, mood, recovery and performance
A dissertation submitted in fulfilment of the requirements for the degree of Master of Science in Medicine to the Faculty of Health Sciences, School of Therapeutic Sciences, University of the Witwatersrand, Johannesburg, 2020