Elite athletes and sports training during the COVID-19 pandemic: A mini review

Purpose – Thecoronavirusdisease2019(COVID-19)pandemichaddevastatingimpactonsportingactivities, education and global health. Given the impact of the pandemic-related restrictions and closed fitness centers and other sports facilities, the coping strategies adopted by athletes while training at home to continue their training remain an important question. The purpose of this review is to examine the findings of key studies focusing on the impact of the pandemic on sport training


Introduction
The corona virus disease 2019 (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus and was discovered in late December, 2019 in the City of Wuhan, China.Thereafter, it spread rapidly throughout the world.It was declared an emergency on January 30, 2020 and a global pandemic on 11 th March, 2020 by the World Health Organisation (WHO, 2020).The disease affected more than 225 countries and territories as at year 2021 (WHO, 2021).Its high rate of infection and dreadful speed of transmission led to stringent measures by government agencies and health organizations, which included social or physical distancing, declaration of lockdowns by countries in order to prevent person-to-person contact or any kind of social gathering or congregation, like sporting events all aimed at minimizing peak infection rate (Gupta et al., 2022).
The lockdowns imposed due to the COVID-19 pandemic had a profound impact on all aspects of human life, including the sporting world, with unprecedented consequences for sports development.Sporting activities across the board were severely affected, resulting in the closure of sports venues and facilities, postponement of sporting events, such as local leagues and international competitions like Union of European Football Associations (UEFA) (March 23, 2020), as well as the rescheduling of the 2020 Tokyo Olympics and Paralympics to July, 2021 (Sayyd, Zainaddin, & Seraj, 2021;Wilshire, Supriya, & Baker, 2021).Many sporting events, including university sports, were outrightly cancelled, and elite athletes, including professionals, Olympic/Paralympic competitors, and Collegiate athletes (Reardon et al., 2019;Urbanski, Szeliga, & Tasiemski, 2021) were all compelled to stay at home (SAH).
The pandemic also had devastating consequences on sport economy, resulting in a significant decrease in revenue (Alam & Abdulraheem, 2023).Professional sports and competitive leagues suffered from low income due to the absence of revenue from gate takings.Other sources of income, such as concessions, merchandise sponsorship and broadcasting, were severely affected (Wiltshire et al., 2021).It was estimated that the sporting leagues in the United States lost approximately USD 13 billion; while some European sporting leagues lost over EUR 1 billion.Additionally, sports events like the annual Wimbledon tennis championships and other Grand Slam tournaments were not spared from the impact of the pandemic (Wiltshire et al., 2021).
With regard to sports performance, the prolonged isolation and quarantine periods prevented athletes from undertaking routine training, culminating in low fitness level and poor mental health (Urbanski et al., 2021;Roche, Sainani, Noordsy, & Fredericson, 2022).Cancellation of institutional campus social activities, including sports, resulted in the isolation of student athletes from team mates during the pandemic (Chandler et al., 2021).It was further observed that the COVID-19 shutdown had a more detrimental impact on sports performance than the traditional off-season period (Grazidi, Lortarco, Baroni, Oliviera, Sagura, & Vanoni, 2020).The pandemic affected virtually all categories of athletes regardless of the level of competition or ranking.Physical activity (PA), training and practice of all sports were compromised.For instance, there was a significant reduction in all aspects of training including, intensity, frequency, duration and even types of activities undertaken (Washif, Farooq et al., 2022;Urbanski, Rogoza, Brewer, & Tasiemski, 2023).
Uncertainties associated with the pandemic also adversely affected the mental health of athletes (Chandler et al., 2021;Haan et al., 2021).From the foregoing, there is substantial evidence that the COVID-19 home confinement resulted in a decline of all levels of PA, including athletes' routine training which led to reduced fitness and frustration arising from the lack of competitions in sports for all categories of athletes (Machado, Secchi, Camargo, & Mendonca, 2023).The effect of the pandemic on sports activities remains a vibrant topic of research in the days ahead.Although, the imposed worldwide lockdown was aimed at minimizing the rapid spread of the disease, it had severe consequences on athletes' daily routines and general PA (Da Silva et al., 2022;Washif, Farooq et al., 2022;Park, Zhong, Yang, Jeong, & Lee, 2022).
The impact of the pandemic on physical conditioning and coping strategies adopted by athletes to continue their training while at home remains an important question.It is also crucial to understand the lessons learned during the periods of confinement and how to mitigate the impact of future pandemics on sport performance and health of athletes.Furthermore, the question whether the negative impact of the pandemic is similar across sport type and sexes is not well understood.Therefore, it is important to provide information on the state of current knowledge regarding this subject in order to fully appreciate the challenges faced by athletes during the lockdown period.Such information would be useful to athletes, coaches, and sport and health policy makers in containing similar emergencies should they occur in future.The purpose of this review is to summarize the existing literature regarding the effect of COVID-19 lockdown on athletes' training habits and practices, while providing suggestions for physical conditioning during periods of isolation.
After conducting a thorough search of databases, including Google Scholar, Scopus and PubMed, the review highlights the need for athletes to remain active during periods of isolation, and examines the findings of key studies focusing on the impact of the pandemic on sport training and the common home-based activities practiced by athletes during the pandemic.Gaps in the literature that may be critical perspectives for future research are identified.A total of 65 relevant articles were selected while non-relevant papers were expunged.Only peerreviewed empirical and quantitative articles published in English language between January, 2020 and May 2023 were included in the review.Out of the 65 papers selected, eight that met the inclusion criteria for this review were eventually chosen and evaluated.

Need for training during COVID-19 pandemic
The normal training cycle for athletes includes the off-season cycle, during which athletes engage in reduced levels of PA for recovery and health reasons.The pandemic creates a need to train at a level similar to that of the off-season level due to the reasons adduced by Andreato, Coimbra, & Andrade (2020) which are summarized in Table 1.
The need for athletes to remain active during the pandemic arose from the imperatives of boosting immunity, injury prevention, and other health and performance outcomes.Highperformance athletes irrespective of sport discipline, who are able to keep fit and active, are more likely to face fewer problems during the return to normal training and competition.Without prejudice to conditioning during periods of restriction, coaches and other professionals should bear in mind that the length of home confinement is important, as longer periods are likely to have relatively more negative effects on athletes.

Training habits and practices during the pandemic
Several investigators have documented training habits and practices among elite athletes during the lockdown period (Washif, Farooq et al., 2022;Washif, Sandbaak et al., 2022;Da
Information from these studies can guide stakeholders in sport to take proactive measures against future occurrence of similar challenges.Findings from the studies included in this review are contextualized and discussed.

Home-based activities during the pandemic
In general, athletes need to maintain a physically active lifestyle but this became a daunting challenge during the pandemic due to the prolonged SAH period.Indeed, the fastmoving world was brought to a standstill.In order to fulfill their health and fitness needs, athletes resorted to home-based exercise during the isolation period.Available evidence shows that aerobic and strength training activities were the major home-based PA performed by athletes world-wide (Kaur, Singh, Arya, & Mittal, 2020;Mutz & Gerke, 2021;Santos et al., 2021).
Many of the world-class athletes trained using available facilities at home, including courtyards, garages, sitting-rooms, corridors and other available spaces within and outside the house.Common activities included body weight exercises using machine or free weights, and muscular strength and endurance activities like push-ups, curl-ups and step-ups.Alternative endurance training modalities included cycle ergometry, aerobic dance, walking and treadmill exercises.Examples of aerobic and strength training can be found online (Insider, 2020) and Figure 1.

Parameter Description
Boosting the body's immunity In order to reduce the risk of infection, athletes need to engage in PA for boosting and maintaining immunity.All that is needed during this period is to focus on the technical and metabolic characteristics of each sport.There is no single training routine for all sports.However, there is a caveat.The intensity of such activities should be moderate because it has been reported that highintensity training may lead to post-exercise immunosuppression which could last for about 24 hours after exercise (Yousli, Bragazzi, Briki, Zmijewki, & Chamari, 2020)

Minimizing the effects of detraining
There is also a need to minimize the effects of detraining and facilitate a return to routine activities after confinement.There was a substantial reduction in all variables of training during the lockdown period.For instance, training duration decreased from three hours to one hour daily, intensity from "high" to "moderate", and frequency, from 6-7 days to 3-5 days per week • Participants engaged in alternative activities such as the use of video games, especially virtual reality and calisthenics to enhance their PA levels • In addition to the negative effect of the confinement on the physical condition of athletes, their mental health was also negatively affected, including depression and anxiety (continued ) Training intensity was determined using the perceived exertion method (Borg's scale).Athletes reported "somewhat hard" or "hard" for cardiovascular and resistance activities, and "easy" or "very easy" for yoga/stretching exercise.There was more variation in intensity reported for sportspecific activities

•
Most athletes indicated that their training "was less effective" as opposed to "more effective" or "same" during SAH compared to pre-pandemic period

Challenges, opportunities and future research directions
The prolonged isolation and quarantine during the pandemic created serious challenges for athletes, coaches and other stakeholders.Planning of training programs is a major mandate for sports managers and coaches, but due to isolation and social distancing, training in many sports were disrupted.Another serious crisis resulting from the shutdown was inadequate or lack of sports facilities and equipment since athletes were compelled to SAH.This situation led to all forms of improvisations (Figure 1).The shutdown also led to a drastic reduction in adherence to training and sport participation especially among young athletes.Many athletes failed to continue participation in training and general PA even after the pandemic receded,

Elite athletes and sports training
mainly due to negative attitudes, lack of motivation and confidence.Inadequate training resources on the part of parents to aid their wards' participation in sports was another factor associated with low adherence to sport participation (Elliot et al., 2021).The Covid-19 pandemic is not all bad news after all, as it has its positive sides to athletes and other stakeholders in sports.For instance, the home confinement and other restrictions provided athletes the opportunity of escaping from pressures associated with training in the full glare of the public and cameras.The reduction in training load or break from continuous training and competitions with attendant chronic fatigue, is another positive aspect of the pandemic.It was also reported that the COVID-19 lockdown protected both referees and teams from undue social pressures due to absence of spectators during competitions, that is, "ghost games" in sports like soccer, basketball, darts, and others (Greve, Meurs, & Strauss, 2023;Angells & Reade, 2023;Leitner & Richlan, 2021).Another positive side of the pandemic was that sport organizations had to adapt and find innovative ways to engage their clients in maintaining their PA.This they did through social media and digital communications such as the use of remote and online platforms for sports activities and business (Glebova, Zare, Desbordes, & Greezi, 2022).
The saying that "every crisis is an opportunity in disguise" is relevant to the Covid-19 pandemic as it provided new opportunities in the world of sports and PA like never before.For instance, many online forums emerged as safe ways for interaction between athletes and their coaches.During this period, many events went virtual, for example, conferences and sports events.Furthermore, the pandemic and related restrictions provided opportunities to develop and deploy new digital technologies in sports, including digital sports application such as online training, e-learning platforms and organization of online sports competitions (Glebova et al., 2022).
Among the opportunities created by the pandemic is that of research.It has brought up many research questions that need to be addressed in the near future.Future studies may investigate similar challenges based on gender inequalities in the various sports; the impact of pandemics on sports participation and general PA in the special and vulnerable populations; assessment of physical fitness of athletes before and after the pandemic; preventive strategies, potential treatment options and safety measures during return to active sports participation after infection.

Discussion
This review summarizes the impact of COVID-19 pandemic on physical training in highperformance athletes, and as major findings the COVID-19 home confinement had a detrimental effect on athletes in all competitive sports in both able-bodied and those with disabilities worldwide.All elements of training, including intensity, frequency and duration were significantly reduced and majority of athletes engaged mainly in cardiovascular and resistance-type training in contrast to sport-specific training, with athletes in team sports being more affected than those in individual sports.Furthermore, a good proportion of the athletes trained individually, in some cases up to about 84% of athletes (Jagim et al., 2020).This scenario was reported in some of the studies reviewed (Da Silva et al., 2022;Washif, Farooq et al., 2022;Chandler et al., 2021).However, a study reported no changes in training volume, intensity and fitness in paralympic athletes (Shaw, Bertrand, Deprez, Ko, Zello, & Chilibeck, 2021).As the lessons from the shutdown are instructive, coaches, and other professionals should have much to learn from the experience in case of future similar occurrences.
The difficulty in training experienced by athletes during the SAH was mainly due to longer lockdown lengths imposed by different countries (Radziminiski et al., 2021) and lack of access to facilities.These situations forced athletes to improvise sport facilities and equipment in order to get going with their training.For instance, many athletes resorted to training in garages, sitting-rooms, courtyards, and other available spaces and equipment within and outside their homes (Figure 1).In some cases, these trainings were carried out remotely by coaches or through virtual reality (Urbanski et al., 2021;Da Silva et al., 2022;Jagim et al., 2020).
Except for resistance training, little or no gender differences in the negative effect of home confinement were reported in some studies (Washif, Sandbaak et al., 2022;Chandler et al., 2021).Furthermore, the frustration resulting from lack of adequate training and competitions and the fear of infection affected the mental health of athletes, especially depression and anxiety (Washif, Farooq et al., 2022;Da Silva et al., 2022;Urbanski et al., 2021).In planning for training during periods of emergencies, coaches and other stakeholders in elite sport should make adequate preparation for athletes' mental care.The need to make adequate preparation for training athletes in team sports is critical.
One of the major limitations of most of these studies was the cross-sectional design which is time-dependent, and also precludes inference of cause-effect relationship.With the exception of Radziminski et al. (2021) study which used a quasi-experimental design, all other studies adopted a cross-sectional design.The online nature of the instrument also limits participation, especially among the participants with no internet access, and this could have led to potential biases in the sample.Another limitation concerns the small sample sizes in some of the studies (Da Silver et al., 2022;Jagim et al., 2020;Santika et al., 2020).This could have led to the problem of external validity.
The major limitation of this review was the restriction to peer-reviewed quantitative studies.This might have resulted in the exclusion of relevant qualitative studies on the subject-matter.However, the major strength of this paper is the inclusion of some studies with large samples of participants from all the continents, with findings reflecting word-wide perception of athletes concerning sport training during the pandemic.The inclusion of Paralympic athletes is another strength, as this also improved our understanding of the situation in athletes with disability.

Conclusions
The COVID-19 pandemic had a negative impact on sports activities globally.The need for athletes to have engaged in PA during the lockdown pertain to boosting immunity, preventing detraining, injury prevention, and getting ready for return to normal sporting activities post-lockdown.
Elite athletes, especially those in team sports, suffered greater decline in training volume and general physical fitness than those in individual sports.Athletes also suffered substantial reduction in physical fitness and all aspects of training, with elite athletes retaining training specificity to a greater extent than athletes of lower classes.
Many athletes experienced difficulty training during the SAH period, mainly due to varying lockdown lengths and restrictions imposed by various countries.Also reported in the studies reviewed were issues related to limited equipment and low motivation among athletes.
Additionally, the pandemic had a negative impact on athletes' training habits, practices and mental health.Gender differences in the influence of pandemic on training were negligible in many sports, except for resistance training in which female athletes were more disadvantaged.
Lessons from the challenges of the pandemic should serve as a guide for stakeholders in the sport industry, while preparing them for similar challenges in the future.Specifically, the following suggestions are proffered.
(1) Governments and sporting organizations should make provision for the utilization of new technology such as virtual reality and mobile applications to promote remote training, training monitoring and athlete education during future isolation periods.

Elite athletes and sports training
(2) Specific policies should be developed based on the lessons from the COVID-19 pandemic to help athletes maintain training and competition comparable to normal levels during future periods of emergencies.
(3) Where possible, bubble training facilities should be provided as avenues for athletes to maintain training levels similar to normal levels.This approach is however capitalintensive, and prolonged camps may result in psychological challenges, such as mental health abnormalities.
(4) Future studies should focus on viable home-based PA with the application of all elements of training that will maintain athletes' fitness and skill levels.
Figure 1.Images of athletes training at home during the lockdown, online at insider YouTube account (2020) Athletes need to remain physically active during the pandemic in other to maintain physical fitness and physiological adaptations Injury prevention Athletes need to prepare for a return to normal sport calendar.They can do this by engaging in exercise routines that prevent injury when they return to normal activities.Such exercises should include mobility, flexibility, core stabilization, balance and weight exercises.These activities require simple equipment.Adoption of FIFA prevention programme adapted for the home environment is a good option (Silvers-Granelli et al., 2015) Prevention of excess body mass and fatDue to detraining resulting from a long period of isolation, athletes need to engage in PA during the pandemic.Accumulation of excess weight and fat has a negative effect the on physical performance and health of athletes Focusing on tactical training Athletes can improve their tactical knowledge and skills by studying match and performance analyses of their team as well as opponents during the pandemic Source(s): Authors' own creation