The cumulative and residual fatigue response associated with soccer-specific activity performed on different playing surfaces

Quo Vadis Nordic Hamstring Exercise-Related Research?-A Scoping Review Revealing the Need for Improved Methodology and Reporting

The objective of this scoping review is to assess Nordic Hamstring Exercise quality (ANHEQ) of assessments and interventions according to the ANHEQ rating scales and to present practical recommendations for the expedient design and reporting of future studies. A total of 71 Nordic Hamstring Exercise (NHE) assessments and 83 NHE interventions were selected from the data sources PubMed, Scopus, and SPORTDiscus. Research studies which were presented in peer-reviewed academic journals and implemented the NHE during laboratory-based assessments or multi-week interventions met the eligibility criteria. NHE assessments analyzed force (51%), muscle activation (41%), knee angle kinematics (38%), and bilateral symmetry (37%). NHE interventions lasted 4-8 weeks (56%) and implied an exercise volume of two sessions per week (66%) with two sets per session (41%) and ≥8 repetitions per set (39%). The total ANHEQ scores of the included NHE assessments and interventions were 5.0 ± 2.0 and 2.0 ± 2.0 (median ± interquartile range), respectively. The largest deficits became apparent for consequences of impaired technique (87% 0-point-scores for assessments) and kneeling height (94% 0-point-scores for interventions). The 0-point-scores were generally higher for interventions compared to assessments for rigid fixation (87% vs. 34%), knee position (83% vs. 48%), kneeling height (94% vs. 63%), and separate familiarization (75% vs. 61%). The single ANHEQ criteria, which received the highest score most frequently, were rigid fixation (66% of assessments) and compliance (33% of interventions). The quality of NHE assessments and interventions was generally 'below average' or rather 'poor'. Both NHE assessments and interventions suffered from imprecise reporting or lacking information regarding NHE execution modalities and subsequent analyses. Based on the findings, this scoping review aggregates practical guidelines how to improve the design and reporting of future NHE-related research.

A commentary on soccer match-play simulations for applied research and practice

Soccer is a fast-growing area of research, demonstrated by a 10-fold increase in the number of PubMed articles derived from the search term 'soccer' between 2001 and 2021. The scope of contemporary soccer-related articles ranges from match-play observations to laboratory evaluations of performance. The activity profile of soccer match-play is variable and techniques to collect data within matches are limited. Soccer-specific simulations have been developed to simulate the evolving demands of match-play. The evolutionary designs of novel simulations provide a reproducible exercise stimulus for varying researcher and practitioner objectives. The applied researcher can utilise simulations to investigate the efficacy of nutritional interventions and environmental stress on performance, while assessing the physiological and biomechanical responses to representations of match-play. Practitioners can adopt simulations for rehabilitation to progressively facilitate return-to-play processes, while implementing extra top-up conditioning sessions for unused and partial-match players. However, there are complexities involved with the selection of varying simulations which are dependent on the research question or practical application. There also remains a paucity of published information to support researchers and practitioners in selecting from differing simulation models. To assist with researcher and practitioner interpretations, we present a commentary of the current simulations to inform decision-making processes for research and training purposes and enhance the application of future research. An objective scoring system was adopted for rating the research and practical applications of each simulation design. Overall scores of 22, 16 and 18 out of 36 were revealed for free-running (n=7), non-motorised- (n=4) and motorised-treadmill-based simulations (n=4), respectively.