Abstract
that three to ve million sports injuries occur worldwide each year. The highest incidence is reported during competition periods with mainly affectation of the musculoskele- tal tissue. For appropriate nutritional management and correct use of nutritional supplements, it is important to individualize based on clinical effects and know the adaptive response during the rehabilitation phase after a sports injury in athletes. Therefore, the aim of this PRISMA in Exercise, Rehabilitation, Sport Medicine and Sports Science PERSiST-based systematic integrative review was to
affectation of the musculoskele- tal tissue. For appropriate nutritional management and correct use of nutritional supplements, it is important to individualize based on clinical effects and know the adaptive response during the rehabilitation phase after a sports injury in athletes. Therefore, the aim of this PRISMA in Exercise, Rehabilitation, Sport Medicine and Sports Science PERSiST-based systematic integrative review was to perform an update on nutritional strategies during the rehabilitation phase of musculoskeletal injuries in elite athletes. After searching the following databases: PubMed/Medline, Scopus, PEDro, and Google Scholar, a total of 18 studies met the inclusion criteria (Price Index: 66.6%). The risk of bias assessment for randomized controlled trials was performed using the RoB 2.0 tool while review articles were evaluated using the AMSTAR 2.0 items. Based on the main ndings of the selected studies, nutritional strategies that bene t the rehabilitation process in injured athletes include balanced energy intake, and a high-protein and carbohydrate-rich diet. Supportive supervision should be provided to avoid low energy availability. The potential of supplementation with collagen, creatine monohydrate, omega-3 ( sh oils), and vitamin D requires further research although the effects are quite promising. It is worth noting the lack of clinical research in injured athletes and the higher number of reviews in the last 10 years. After analyzing the current quantitative and non-quantitative evidence, we encourage researchers to conduct further clinical research studies evaluating doses of the discussed nutrients during the rehabilitation process to con rm ndings, but also follow international guidelines at the time to review scienti c literature. Keywords: sports injury; musculoskeletal pain; nutrients; dietary supplements; sports nutrition; sports nutritional physiological phenomena; athletic injuries 1. Introduction Currently, elite athletes are subjected to a grueling competitive calendar [1] which is generally associated with a higher training volume and competition load [2]. The consequence of this competitive model is not only reduced performance, as has been reported in several sports [36], but also an increase in the occurrence of lesions. In recent Nutrients2023,15, 819.
a higher training volume and competition load [2]. The consequence of this competitive model is not only reduced performance, as has been reported in several sports [36], but also an increase in the occurrence of lesions. In recent Nutrients2023,15, 819.
Nutrients2023,15, 819 2 of 25 years, studies on injury prevention [7] along with the technologies and strategies to prevent them have increased exponentially; however, the incidence of sport-related injuries has remained constant [8]. An injury episode can be expressed as the number of injuries that the athlete may suffer per 1000 h of exposure to the risk of injury, both in training and in competition. It is estimated that an average of 3 to 5 million sports injuries occur in a year [9], with the prevalence being higher during competitions (72.2%) than during training (21.8%) [10]. For instance, Dupont et al. [11] reported a 6.2 times higher injury rate in soccer players who played two games a week compared to those who played only one, with the majority of injuries (76%) caused by overuse. In general, the injury rate in soccer is mostly signi cant during games/matches (9.5 to 48.7 injuries/1000 h in competitive male youth players, 2.5 to 8.7 injuries/1000 h in male professional players, and 12.5 to 30.3 injuries/1000 h in female players) [12]. Importantly, it has been reported that approximately 81 per 1000 elite athletes suffered an injury during competition at World Championships with a 40.9% prevalence of musculoskeletal injuries [13]. Similarly, a college basketball player has a rate of 9.9 injuries per 1000 h of competitive games, while only 4.3 injuries are sustained per 1000 h of training [14]. In the National Basketball Association professional league, the exposure rate per player is 3.26 injuries per 1000 h of competitive play, with the prevalence being higher in the rst month of the league [15]. The number of musculoskeletal injuries and illnesses suffered by athletes during a season has recently been related to sporting success, showing that the lower the number of sporting injuries, the higher the performance [16]. In particular, soft tissue injuries involving muscle, tendons, and ligaments are very common at all levels of sport [17]. The most frequent injuries are muscle (especially in the hamstring muscles [18]), ligament (i.e., anterior cruciate ligament rupture [19]), and joint (i.e., ankle sprain [8]) injuries. In fact, up to
lower the number of sporting injuries, the higher the performance [16]. In particular, soft tissue injuries involving muscle, tendons, and ligaments are very common at all levels of sport [17]. The most frequent injuries are muscle (especially in the hamstring muscles [18]), ligament (i.e., anterior cruciate ligament rupture [19]), and joint (i.e., ankle sprain [8]) injuries. In fact, up to 80% of injuries generally affect the musculoskeletal tissue. For instance, deltoid muscle injuries per year are between 12 and 19% in baseball players and between 23 and 38% in swimmers [20]. In marathon runners, the incidence of training-related lower limb muscle injuries is estimated to be between 19 and 58% [21]. In tennis, about 3.49 injuries/1000 h have been reported frequently in joints (29.5%), tendinopathies (22.1%), ankle (20%), and wrist (15.8%) [22]. Generally, two stages of management can be considered in the rehabilitation process from a sport injury [23]. The rst stage corresponds to the phase of immobilization, atrophy, and subsequent tissue repair. This stage can last for several days or months depending on the severity of the injury. Normally, it is a period that leads to deconditioning due to the lack of movement of the affected body section. This might evoke signi cant loss of muscle mass as well as functional alterations of the musculoskeletal and connective tissues [24]. Some nutritional strategies are suggested to contribute to the protection/repair of muscle tissue and modulation of the immune system by controlling catabolic and in ammation processes through the regulation of reactive oxygen species (ROS) production and catabolic pathways [17,25,26]. However, to date, the effect of these nutrients on the rehabilitation of elite athletes is unclear or even ambiguous in certain contexts [27]. The second stage corresponds to the readaptation to training and improvement of the psychological pro le (i.e., emotional level) of the athlete. Some authors refer to this as the reathletization phase [28]. We have recently highlighted the compensatory neural changes (e.g., brain cortical changes) and the cognitive load that might affect recovery and relapse after a musculoskeletal injury [29]. Since early mobilization and stimulation of the affected tissue
training and improvement of the psychological pro le (i.e., emotional level) of the athlete. Some authors refer to this as the reathletization phase [28]. We have recently highlighted the compensatory neural changes (e.g., brain cortical changes) and the cognitive load that might affect recovery and relapse after a musculoskeletal injury [29]. Since early mobilization and stimulation of the affected tissue (i.e., low-intensity pulsed ultrasound, neuromuscular electric stimulation) has been shown to have a positive effect on collagen reorganization and general connective tissue repair, it is recommended to start with a controlled loading program as soon as pain or injury permits [6]. It is worth noting that medical personnel, physiotherapists, and athletic trainers should respect the natural healing process of the human body and ensure a balance between workload and rest time to avoid longer lasting tissue damage [30,31]. To facilitate the recovery of physical-related parameters, a multidisciplinary team of sports practitioners is needed to cover the energetic, nutritional, and psychological among
Nutrients2023,15, 819 3 of 25 other demands of the injured elite athletes. Our group has emphasized that adopting a sys- temic (integrative and multifactorial), evolutionary (intuitive), and adaptive (ever-changing based on individualization) perspective or `Bio-Logic approach' [32] would enhance our understanding of the ow of information through interactions between system components and their regulatory aspects for a given phenotype and the allostatic load. Indeed, the allostatic load (as the cost a biological system must pay in order to reset physiological parameters [e.g., injury recovery] during the adaptation [33]) has been proposed as a promising and underutilized measure that might be useful to assess the spinal cord injury time course [34]. Importantly, nutrition is one of the many factors that might impact the allostatic load and, thereby, it might in uence the musculoskeletal tissue overload and repair. Therefore, a special nutritional intervention throughout the rehabilitation process is warranted to ensure integral recovery while accelerating tissue regeneration [24]. In this regard, it should be noted that tissue repair is a high energy-consuming process (i.e., protein synthesis, cytoskeleton remodeling, etc.). As a result, the energetic and protein de - ciency might hamper proper healing and increase the in ammatory response which would decrease the rate of tissue recovery while increase injury relapse [23]. In this sense, the aim of this systematic integrative review was to update the effective nutritional strategies that bene t the rehabilitation of musculoskeletal injuries in elite athletes. 2. Methods This study employed the ve stages developed by Whittemore and Kna [35] as the established guidelines of the integrative review. This allows for the combination of past empirical or theoretical literature to provide a more comprehensive understanding of a particular phenomenon or healthcare problem, which has a greater impact to establish evidence-based recommendations. The aim was to synthesize the occurrence of literature regarding nutrition interventions for the injured athlete. Similar to previously published articles [36], the review methodology was enhanced by optimizing the stages of literature search, data evaluation, and data analysis in order to systematize the review process and improve the scienti c soundness according to recommendations given by
establish evidence-based recommendations. The aim was to synthesize the occurrence of literature regarding nutrition interventions for the injured athlete. Similar to previously published articles [36], the review methodology was enhanced by optimizing the stages of literature search, data evaluation, and data analysis in order to systematize the review process and improve the scienti c soundness according to recommendations given by Hopia et al. [37] and the PRISMA in Exercise, Rehabilitation, Sport Medicine and Sports Science (PERSiST) guidelines [38]. The protocol of this review was published and freely accessible at Figshare to avoid unnecessary duplication (DOI: 10.6084/m9. gshare.21399696). 2.1. Eligibility Criteria The inclusion criteria for this review were as follows: (1) Empirical or theoretical articles (quantitative, qualitative, mixed method studies, and systematic reviews) that assessed or included elite/high-performance male and female athletes over 18 years of age. Only review articles that evaluated the use of nutrients in the rehabilitation phase after a musculoskeletal sports injury were reported or discussed; (2) studies were published between 2012 and 2022; (3) articles were written in the English and Spanish language; (4) available in full text; and (5) focused solely on the assessment of nutritional (energy intake, macronutrient distribution, micronutrients, etc.) or supplementation strategies during the rehabilitation process in injured athletes. On the other hand, the exclusion criteria consisted of articles that: (1) Included children, older adults, physically active peo- ple, amateur or recreational population and non-conventional athletes; (2) commentaries, dissertations, theses, editorials, letters to the editor, and books; (3) interventions where the dosage and timing of intake of nutrients and sports supplements were not speci ed; and (4) articles that did not analyze the relationship between nutrition and musculoskeletal sports injuries (e.g., concussions). 2.2. Information Sources The following academic databases were selected to examine the literature: PubMed/ Medline, Scopus, PEDro, and Google Scholar.
Nutrients2023,15, 819 4 of 25 2.3. Search Strategy The patient, intervention, comparison, and outcome (PICO) strategy was utilized for structuring the research question: P (athletes aged >18 years old) I (nutritional intervention) C (placebo, or non-exposed control group [pre-post]) O (musculoskeletal recovery- or rehabilitation-related outcomes) [39]. The authors followed the identical string in searching the databases to ensure consistency with the data search, as follows: (i) Pubmed/MedLine, (Nutrition OR supplementation) AND sports AND inju*, and sports injuries OR ath- letic injuries OR sport injury rehabilitation AND (nutrition OR dietary supplements); (ii) Scopus, sports injuries OR athletic injuries OR sport injury rehabilitation AND (nutrition OR dietary supplements). In addition, further papers were hand searched (e.g., snowballing) in the databases. The data search in PEDro and Google Scholarwas performed using free language terms, such as nutrition, supplementation, and musculoskeletal injuries. 2.4. Selection Process After executing Boolean algorithms, lters were used in the different databases to select potentially eligible articles. Four authors independently evaluated the databases for articles that met the inclusion criteria (J.E.G-V., M.A.C-G., E.J.R-A., and D.A.B.). Dis- crepancies were identi ed and resolved through discussion (with a fourth author where necessary). Those publications that met all the requirements went on to the next phase of data analysis and synthesis. The database search took place during June and October 2022 to capture relevant articles for the review, although an updated search was conducted prior to manuscript submission. 2.5. Data Collection Process and Items A table to synthesize results and ndings was built with the following data: (i) General information on the study (title, author, year, and type of study); (ii) description of the study population; (iii) study aim and methodology; (iv) characteristics of the nutritional and/or supplementation strategy (timing and dosage); and (v) main ndings of the study. 2.6. Study Risk of Bias Assessment Risk of bias assessment for randomized clinical studies was performed using the Cochrane RoB 2.0 tool (RoB2 Development Group, University of Bristol, Bristol, UK) [40]. Five bias domains (randomization process, deviations from intended interventions, miss- ing outcome data, outcome measurement, and selection of the reported outcomes) were evaluated
(v) main ndings of the study. 2.6. Study Risk of Bias Assessment Risk of bias assessment for randomized clinical studies was performed using the Cochrane RoB 2.0 tool (RoB2 Development Group, University of Bristol, Bristol, UK) [40]. Five bias domains (randomization process, deviations from intended interventions, miss- ing outcome data, outcome measurement, and selection of the reported outcomes) were evaluated [41]. The overall assessment of the risk of bias for each outcome was presented as: `Low risk', `some concerns', or `high risk' of bias. We used the AMSTAR 2.0 checklist in order to assess the methodological quality of the selected review articles [42]. The 16 items presented to determine the classi cation of the systematic review as `reliable' or `not very valid' were considered [43]. 3. Results 3.1. Study Selection After running the search algorithms with Boolean operators and free language terms, 3736 references were obtained. Filtering by date, type of article, language, and availability of full text resulted in 1065 potentially eligible studies. It should be noted that +100 clinical trials were published between 1992 and 2012. However, after screening the abstracts and full texts of these articles and analyzing strict compliance with inclusion criteria, 1045 articles were excluded. A total of 18 studies met the requirements of this integrative systematic review (Price Index: 66.6%). Figure 3.2. Risk of Bias within Studies Compared to review articles, fewer clinical trials have been carried out in the last 10 years. The methodological quality of the ve randomized clinical trials included in this integrative systematic review is shown in Figure.
Nutrients2023,15, 819 5 of 25Nutrients 2023, 15, 819 5 of 29 full texts of these articles and analyzing strict compliance with inclusion criteria, 1045 ar- ticles were excluded. A total of 18 studies met the requirements of this integrative system- atic review (Price Index: 66.6%). Figure 1 shows a flow diagram of the literature search. Figure 1. PRISMA flow diagram. 3.2. Risk of Bias within Studies Compared to review articles, fewer clinical trials have been carried out in the last 10 years. The methodological quality of the five randomized clinical trials included in this integrative systematic review is shown in Figure 2. Figure 2. Risk of bias summary for included studies. Weighed bar-chart of the distribution of risk- of-bias judgments. These graphics were obtained using the ‘robvis’ package within the R statistical computing environment. Similarly, the methodological quality of the twelve reviews included in this system- atic integrative evaluation of the literature was performed with the AMSTAR 2.0 tool (Ta- ble 1). In general, a classification of low quality (high risk of bias) was found in the selected review articles. Therefore, a lack of reproducibility and replicability of the reviews per- formed on this topic is notable to date. Only one retrospective cross-sectional study that evaluated injured Australian and international athletes was included [44]. Figure 1.PRISMA ow diagram.Nutrients 2023, 15, 819 5 of 29 full texts of these articles and analyzing strict compliance with inclusion criteria, 1045 ar- ticles were excluded. A total of 18 studies met the requirements of this integrative system- atic review (Price Index: 66.6%). Figure 1 shows a flow diagram of the literature search. Figure 1. PRISMA flow diagram. 3.2. Risk of Bias within Studies Compared to review articles, fewer clinical trials have been carried out in the last 10 years. The methodological quality of the five randomized clinical trials included in this integrative systematic review is shown in Figure 2. Figure 2. Risk of bias summary for included studies. Weighed bar-chart of the distribution of risk- of-bias judgments. These graphics were obtained using the ‘robvis’ package within the R statistical computing environment. Similarly, the methodological
in the last 10 years. The methodological quality of the five randomized clinical trials included in this integrative systematic review is shown in Figure 2. Figure 2. Risk of bias summary for included studies. Weighed bar-chart of the distribution of risk- of-bias judgments. These graphics were obtained using the ‘robvis’ package within the R statistical computing environment. Similarly, the methodological quality of the twelve reviews included in this system- atic integrative evaluation of the literature was performed with the AMSTAR 2.0 tool (Ta- ble 1). In general, a classification of low quality (high risk of bias) was found in the selected review articles. Therefore, a lack of reproducibility and replicability of the reviews per- formed on this topic is notable to date. Only one retrospective cross-sectional study that evaluated injured Australian and international athletes was included [44]. Figure 2. Risk of bias summary for included studies. Weighed bar-chart of the distribution of risk- of-bias judgments. These graphics were obtained using the `robvis' package within the R statistical computing environment. Similarly, the methodological quality of the twelve reviews included in this systematic integrative evaluation of the literature was performed with the AMSTAR 2.0 tool (Table). In general, a classi cation of low quality (high risk of bias) was found in the selected review articles. Therefore, a lack of reproducibility and replicability of the reviews performed on this topic is notable to date. Only one retrospective cross-sectional study that evaluated injured Australian and international athletes was included [44]. 3.3. Results of Individual Studies Table have been evaluated during the rehabilitation of musculoskeletal injuries in elite athletes.
Description
The review synthesizes evidence on nutritional interventions for injured athletes.