Ole Johan Kemi

Carpels, T, Kelly, S, and Kemi, OJ. Substitutions in professional elite soccer increase distance and high-intensity actions. J Strength Cond Res XX(X): 000–000, 2026—Physical performance in intense domains including distance covered and high-intensity actions are central for success in soccer. During a match, players need to appropriately distribute their capacity for intense match-play to last the full match. Substitutions may mitigate performance losses. Here, we investigated physical performance by global positioning system-tracked total distance, repeated high-intensity efforts and peak metabolic power, and result score impact, of substitutions in top division male professional elite soccer players ( n = 48) in 95 competitive matches over 3 seasons, featuring 253 substitutions. We found that full match-players showed 4% higher maximal oxygen uptake ( p < 0.05) versus substitution players. Relative distance covered in match was 50–74% higher ( p < 0.01) in players who substituted into the match versus players who played the full match or were replaced during the match. Repeated high-intensity efforts in match was 61–93% higher ( p < 0.01) in players who substituted into the match versus those who played the full match or were replaced during the match. These effects occurred in all player positions, and no home and away match differences occurred. Peak metabolic power did not differ between full-match or substitute players. Finally, we found that substitutions were 3–4 times more likely to improve match score than worsen it ( p < 0.01), especially substitutions between 60 and 80 minutes of the match. In conclusion, substitutions permit a team to maintain or increase physical performance, including high-intensity actions, during the course of a match.

We teach that physical activity, exercise, and exercise training are good for us, and that the positive effect is better if we exercise with intensity; the greater the intensity the greater the effect. Indeed, there is clear and irrefutable evidence of intensity-dependence of effect, stemming from a dose-response relationship between effort going into the exercise and the result coming out of it. This leads to the situation where we generally and practically prescribe exercise as intensely as possible, for as long as possible, but this comes in conflict with the speed/power—duration relationship that dictates how long high-intensity exercise may be sustained. The solution we have is high-intensity interval training, referred to as HIIT or just interval training. This is a modality of exercise training that with repeated bouts of high-intensity exercise interspersed by active/passive recovery periods permits accumulation of intense exercise beyond that which would be achievable in a single exercise bout. This is then applied to a range of exercises and locomotion modes. However, while we often refer to and teach concepts of intensity-dependence of exercise training effects, we rarely describe the basics of the actual exercise. Here, we introduce interval training, and by association, intensity, for the physiology-savvy, but non-exercise science educator. We conceptualize the principles of interval training and provide a practical framework and lesson plan for teaching appropriate interval training.

Core to their education mission is that colleges and universities scrutinize assessment and examination via boards of examiners, but this scrutiny has no set standard or protocol. This article gives principles and practical recommendations, with examples, for how this scrutiny could or should be carried out, in a manner that establishes accountability and good practice that study programs and boards of examiners in education may utilize, to improve educational practice.

UK university undergraduate programs are compared by independent subject-specific rankings (Complete, Guardian, and Times), based on data from the National Student Survey, Higher Education Statistics Agency, Universities and Colleges Admissions Service, Research Excellence Framework, and the universities. The sports and exercise science program at the University of Glasgow has steadily risen to currently rank as the top UK program. This investigation aimed to identify the underlying factors that explain this. Therefore, we obtained underlying scores for entry standard, student satisfaction, research foundation, graduate prospects, staff-to-student ratio, expenditure/student, continuation, program support to students, and teaching quality from the ranking providers for years 2010-2024, and statistically modeled which factors significantly affected the rankings. We found that entry standards and graduate prospects strongly correlated significantly with ranking results. Principal component analysis indicated that a model of graduate prospects and entry standards explained 66.2% of the variance in ranking results. Multiple linear regression with all underlying factors included in the model indicated they explained 78% (R-2 = 0.78) of the total variance, while stepwise elimination of insignificant factors identified graduate prospects as the sole factor that significantly affected outcome by explaining 71% (R-2 = 0.71) of the variance. Therefore, the primary predictor of ranking success in UK university league tables for sports science is graduates' professional success (graduate prospects). NEW & NOTEWORTHY University rankings are used by applicants and stakeholders to judge programs, including undergraduate studies. In the rankings, undergraduate UK programs are compared and contrasted against each other based on how they score for criteria that affect student life and future prospects. Here, we determined the relative influence of those criteria and found that graduate prospects, how students professionally benefit from their study after graduation, is the factor that matters most for the ranking results.

Cardiorespiratory performance segregates into rat strains of inherited low‐ and high‐capacity runners (LCRs and HCRs); during adulthood, this segregation remains stable, but widens in senescence and is followed by segregated function, health, and mortality. However, this segregation has not been investigated prior to adulthood. We, therefore, assessed cardiorespiratory performance and cardiac cell (cardiomyocyte) structure–function in 1‐ and 4‐month‐old LCRs and HCRs. Maximal oxygen uptake was 23% less in LCRs at 1‐month compared to HCRs at 1‐month, and 72% less at 4 months. Cardiomyocyte contractility was 37−56% decreased, and Ca²⁺ release was 34−62% decreased, in 1‐ and 4‐month LCRs versus HCRs. This occurred because HCRs had improved contractility and Ca²⁺ release during maturation, whereas LCRs did not. In quiescent cardiomyocytes, LCRs displayed 180% and 297% more Ca²⁺ sparks and 91% and 38% more Ca²⁺ waves at 1 and 4 months versus HCRs. Cell sizes were not different between LCRs and HCRs, but LCRs showed reduced transverse‐tubules versus HCRs, though no discrepant transverse‐tubule generation occurred during maturation. In conclusion, LCRs show reduced scores for aerobic capacity and cardiomyocyte structure–function compared to HCRs and there is a widening divergence between LCRs and HCRs during juvenile to near‐adult maturation.