Relationship Between Objective and Subjective Markers of Muscle Recovery in Professional Handball Players.

PURPOSE: To evaluate the relationship between items of the Short Recovery and Stress Scale (SRSS) related to physical stress and recovery and the biomarker creatine kinase (CK) in professional handball. METHODS: CK and SRSS items (physical performance capability, overall recovery, muscular stress, and overall stress) were assessed in an observational study of 16 adult male professional handball players from a team in the highest German league during the 2019-20 preseason. Their preseason training schedule included several microcycles, each consisting of 3 consecutive days of intense training followed by a rest day. On 5 of these rest days, when players were classified as nonrested, and the 5 immediately following days, when players were classified as rested, players completed the SRSS between 8:00 and 9:00 AM, followed by blood sampling. Correlations between SRSS items were performed using Kendall τ. The relationship between each SRSS item and CK levels over time was examined using a mixed-effects model with a random intercept. RESULTS: CK levels and SRSS stress items were significantly higher and SRSS recovery items were significantly lower in nonrested players. SRSS items were significantly positively or negatively correlated (all items: P < .001) and showed a significant effect indicating lower CK levels in rested players (all items: P ≤ .001; ηp2=.1-.32). CONCLUSIONS: The investigated SRSS items may be a viable option for assessing muscle recovery in adult male professional handball players in a cost-effective and noninvasive manner. They can be used as a single monitoring tool or as part of a multimodal approach.

Biochemical Monitoring of Muscle Recovery in Elite Handball Using an Individualized Approach.

PURPOSE: To evaluate the classification performance of a new method to individualize reference ranges for biomarkers of muscle recovery in elite handball. METHODS: In a longitudinal observational study, creatine kinase (CK) and urea levels were assessed in 16 male elite handball players during the 2019-20 preseason. Blood samples were collected at prespecified time points when players were considered either recovered or nonrecovered. Initially, linear mixed-effects models were calculated, as outlined in the study design, to examine the effect of recovery status on CK and urea levels. Finally, a fixed-effect model was calculated for urea based on the law of parsimony. Individualized reference ranges were calculated using a recently published algorithm. To investigate whether the individualized approach resulted in a more accurate classification of recovery status (recovered or nonrecovered), it was compared with a group-based approach derived from the same data set, utilizing predefined error rates. RESULTS: Linear mixed-effects models showed a large effect of recovery status on CK (P < .001, d = 3.49) and a small effect on urea (P = .018, d = 0.382). In contrast to CK (P = .017), urea had no significant interindividual variation. Hence, individualization was examined only for CK. The numerical decrease in both CK error rates by the individualized approach was significant for the test-pass error rate (P = .0196, ϕ = .19). CONCLUSIONS: Our findings underscore the critical role of CK for monitoring in team sports such as handball. The observed improvement in CK error rates suggests a promising opportunity to individualize biochemical monitoring, although further studies encompassing larger sample sizes are warranted.

[Monitoring and load management in team handball]. / Monitoring und Belastungssteuerung im Handball.

BACKGROUND: The monitoring of athletes has become a focus in elite-level team sports and research in recent years. The goal is to optimise load management for maximising performance. Due to the considerable amount of data gathered during monitoring in team sports, the trend is towards integrating different monitoring methods in a software-based tool. In addition, decision-support systems are used in order to enable coaches to make quick decisions to control further burdens. This article is intended to give an overview of the large number of monitoring methods used in contact team sports, to consider their test quality criteria and to check a useful application of monitoring methods for team handball, taking into account the sports-specific requirements. METHODS: PubMed-based review of the literature. Narrative review focusing on current data from the years 2010 to 2019. RESULTS: Demands on athletes in elite team handball vary depending on the playing position. Therefore, individualised load control is necessary. Monitoring methods with proven validity and reliability should ideally be used in a multivariate approach to represent the various aspects of external and internal load, recovery and fatigue, well-being and readiness. It is important to know the meaningful change for each athlete while using a monitoring method. This circumstance necessitates an individualised approach for each parameter. There are not many studies on the use of monitoring methods in team handball, neither in the amateur field nor in an elite sports environment. Nevertheless, based on evidence from other contact team sports, a recommendation for a combined use of monitoring methods can be given. Burden, time and cost/benefit should always be considered. CONCLUSION: There is a considerable need for research regarding the use of athlete monitoring in team handball. The combination of monitoring methods proposed in this article can be used as a framework for studies with handball players in an elite sports environment in order to implement an increasingly handball-specific monitoring concept in the future.