2/2021
Monica Duarte
Prevalence of dermatomycoses in professional football players : A study based on data of German Bundesliga fitness check-ups (2013-2015) compared to data of the general population
What did they do?
This is an observational study comparing data obtained from professional football players of a team of the first German Bundesliga regarding dermatomycoses (onychomycosis, tinea pedis, and pityriasis versicolor) to an age-matched cohort of employees from different industrial sectors in Germany who participated in a skin cancer screening programme.
The authors found that onychomicoses, tinea pedis, and pityriasis versicolor were by far more common in football players (60.7%, 36.9%, and 17.8% respectively) when compared to the group of employees (3.3%, 3.2%, and 1.4%, respectively).
Why is it important?
It becomes clear that the prevalence of dermatomycoses is considerably higher in football players when compared to a control group, this is not always the case for other infectious illness.
Things to consider?
There are some differences between both groups. The comparison group was made up of 8186 subjects who participated in an occupational extended skin cancer screening program, while the football players were 84; data from the football players were collected in 2013 and 2015, whereas for the comparison group data were collected from 2006 to 2012. More importantly, the diagnoses in the comparison group were based on clinical examination only, as opposed to the football player group, where microbiological analyses was carried out.
Take home message?
Football players have a higher prevalence of dermatomycoses when compared to the general population. This is likely due to the use of tight footwear and mechanical stress, which can lead to nail and skin injuries which represent entry points for pathogens. Other risk factors include hyperhidrosis, frequent showers in shared shower rooms, inadequate washing of socks in shared washing machines, etc.
Why I chose this article?
Dermatomycoses, although common, are often overlooked and/or underestimated despite the fact that they can negatively impact performance during training and gameplay and that they are relatively easy to identify and treat.
Reference
Buder, V et al. “Prävalenz von Dermatomykosen bei Profifußballspielern : Untersuchung im Rahmen der Bundesligatauglichkeitsuntersuchung (2013–2015) im Vergleich mit Daten der Allgemeinbevölkerung”. Der Hautarzt; Zeitschrift fur Dermatologie, Venerologie, und verwandte Gebiete vol. 69,5 (2018): 401-407. doi:10.1007/s00105-017-4120-3
Dolores Dravinec
Energy expenditure and dietary intake in professional football players in the Dutch Premier League
What did they do?
The study assessed energy expenditure (EE) by doubly labelled water (DLW) method and dietary intake of professional players over 14 days during competitive football season.
Why is it important?
This is the only observational study that used DLW in a larger (n=41 from three clubs playing in the Dutch Eredivisie) sample of professional football players to quantify EE during the competitive season. The study showed that the average daily EE of a professional football player was about 3300 kcal. When corrected for body mass, daily EE was different between playing positions with the lowest expenditure observed in goalkeepers (38 kcal/kg) and the highest in midfielders (44 kcal/kg). The average daily energy intake (EI), recorded by the 24-h recall method, was about 2700 kcal, indicating underreporting of food intake (~18%). Players habitually increased their carbohydrates (CHO) intake on the match days (5.1 g/kg) compared to the training (3.9 g/kg) and rest days (3.7 g/kg). Daily protein intake was comparable on training and match days (1.7 and 1.8 g/kg), with lower intake on rest days (1.5 g/kg), while the fat intake was not significantly different between days (1.2-1.3 g/kg/day).
Things to consider?
The difference in daily energy requirements is important when prescribing optimal dietary advice for fuelling or recovery. Even though there was no significant variability in average daily EE between players in the same position (3285 ± 354 kcal/day; p=0.65), variation in daily EE was significant when corrected for a body mass (42.4 ± 3.5 kcal/kg BM/day; p=0.004). This could be explained by the position-specific differences in body mass (77.6 ± 8.0 kg; p<0.001) and difference in training (3726–5942 m) and match load (5741–11441 m). The study showed that the external load on match days (total distance covered 10,293 ± 1710 m), was twice as high as the load on training days (5405 ± 835 m) for all playing positions, but the DLW method did not allow the assessment of EE on a day-to-day basis and during isolated training sessions or matches. Moreover, dietary intake was assessed by only three unannounced face-to-face 24h recalls which might be insufficient to represent habitual EI, and goalkeepers were represented by only 4 participants compared to 12 or more players playing other positions.
Take home message?
Daily energy requirements of professional football players can be considered modest. Interindividual differences in EE can be explained by the difference in total and lean body mass, and the difference in energy requirements of position-specific external match load. Players subjected to high training and match loads require more energy (~45 kcal/kg), whereas less active players and goalkeepers may require no more than ~40 kcal/kg. However, individual needs should be considered when providing advice. Daily CHO intake is in general below recommendation (Collins et al., 2020) and could be optimized depending on the exercise intensity and duration. Habitual daily protein intake is sufficient (1.5 – 1.8 g/kg body mass) but the distribution of the protein throughout the day could be improved by consuming a minimum of 20 g of protein at each main meal. Professional football players could benefit from nutritional counselling and improving nutritional intake to support optimal health and performance.
Why did I choose this article?
This article offers the chance to get an idea of what is real energy demand in professional football players. A good understanding of players´ dietary habits, energy and nutrient needs should be the basis of convenient nutrition consulting and in the absence of individual measurements, such information is valuable for guiding players. Furthermore, when prescribing optimal dietary advice aiming to improve a player’s health and playing performance, the basic information should be extended by sufficient information on activity load and other individual requirements. However, specific energy and nutrient requirements dependent on the training and match load should be investigated by future studies.
Reference
Brinkmans, N., Iedema, N., Plasqui, G., Wouters, L., Saris, W., van Loon, L., & van Dijk, J. W. (2019). Energy expenditure and dietary intake in professional football players in the Dutch Premier League: Implications for nutritional counselling. Journal of sports sciences, 37(24), 2759–2767. https://doi.org/10.1080/02640414.2019.1576256
Collins, J., Maughan, R. J., Gleeson, M., Bilsborough, J., Jeukendrup, A., Morton, J. P., Phillips, S. M., Armstrong, L., Burke, L. M., Close, G. L., Duffield, R., Larson-Meyer, E., Louis, J., Medina, D., Meyer, F., Rollo, I., Sundgot-Borgen, J., Wall, B. T., Boullosa, B., Dupont, G., … McCall, A. (2020). UEFA expert group statement on nutrition in elite football. Current evidence to inform practical recommendations and guide future research. British journal of sports medicine, bjsports-2019-101961. Advance online publication. https://doi.org/10.1136/bjsports-2019-101961
Cameron Scullard
Cognitive training in elite soccer players: Evidence of narrow, but not broad transfers to visual and executive function
What did they do?
The study aimed to assess the effectiveness of cognitive training on visual and executive functions, using the NeuroTracker 3-Dimensional Multiple-Object Tracking (NT 3D-MOT), in youth elite soccer players. Twenty-nine male elite players were recruited from the youth academies of professional German football clubs, playing at either top U19 level or 4th national league (U23). The intervention (16) and control (13) groups were subjected to a 75-minute pre-post testing battery separated by a period continuing with their normal soccer training regime, whilst monitoring physical and leisure time activities. The intervention group of 16 players performed cognitive training involving identifying, visually tracking, and memorizing coloured balls for 8 minutes, twice a week for a period of 10 weeks. Results showed significant benefits from direct training of the MOT ability.
Why is it important?
This study contributes to limited literature looking at the effects of a lab-based cognitive training program on a wide variety of visual and executive functions. The results suggest the potential plasticity of the brain to unpredictable, visually complex task-specific cognitive and visual training. Although negligible transfers to visual and executive functions are seen here, the NT 3D-MOT may be adapted to bias specific visual and movement demands for sports specificity.
Things to consider?
Confidence intervals and effect sizes showed a significant improvement in Multiple Object Tracking (MOT) ability among the intervention group in comparison to their control counterparts, but an insignificant transfer to visual and executive functions. The lack of this transfer to executive functions is consistent with previous literature assessing these parameters specifically. Limitations included the exclusion of soccer-specific perception and action combinations associated with dynamic soccer situations which would potentially provide benefits in parameters not tested in this study. The study raises the question of whether sub-elite athletes would have a significant improvement in visual abilities based on the assumption of a lower baseline level and greater capacity for potential improvement.
Take home message?
The study utilized one of the most comprehensive testing batteries for cognitive and visual functions. Moreover, other tested areas which remained unaffected, highlights the potential complexity of each visual and executive function by recommending future interventions to further isolate these systems for more substantial conclusions. Therefore, the transfer of effects from NT 3D-MOT dual-task training require further investigations to warrant its exclusion for practitioners. However, the study provides tremendous insight into the cognitive learning capacity of elite soccer players and lays the foundation for more sport specific measures.
Why I chose this study?
This recently published article attends to aspects of cognition and executive functions which have been historically difficult to understand. However, the current study makes use of recent technological advancements in testing these parameters. The use of elite athletes in the current study allows for future investigations into how sub-elite athletes can strive to emulate the functioning of their higher skilled counterparts.
The parameters assessed in the study are synonymous with the newly developed concept of neuroathletic training, of which minimal research is established. This study contributes to a foundation from which future studies can investigate to the integration of multiple visual and executive functions, as part of a training regime to enhance neurological functioning, for performance within a sport-specific context.
Reference
Scharfen, H. E., & Memmert, D. (2021). Cognitive training in elite soccer players: evidence of narrow, but not broad transfer to visual and executive function. German Journal of Exercise and Sport Research, 51, 135-145. https://doi.org/10.1007/s12662-020-00699-y