[Effects of the COVID-19 lockdown on physical performance parameters in professional football]. / Auswirkungen des COVID-19-Lockdowns auf physische Leistungsparameter im professionellen Fußball: Eine narrative Literaturübersicht.

Background: Governmental measures in 2020 to contain the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) brought training and competition in professional soccer to a temporary halt in many countries. As a result of the lockdown, training possibilities were mostly limited to nonspecific home-based training methods. It is unclear whether the lack of sport-specific stimuli led to a reduction in the physical performance of soccer players. Methods: For the narrative review, the PubMed, Google Scholar and BISp-Surf databases were selectively searched for studies examining the effects of the lockdown on physical performance parameters in adult professional soccer players. Results: In this review six prospective longitudinal studies were included. In all studies home-based training was performed during quarantine. Of the studies four compared the performance of the soccer players with data from previous seasons and two studies assessed the performance of players immediately before and after the lockdown period. Discussion: While general strength and endurance performances can be maintained through home-based substitute training programs, the studies indicated that the lack of football-specific stimuli could have an impact on the rapid power and speed performances of soccer players. Progressive loading control especially for speed training should be considered when returning to regular training in order to reduce the risk of injuries.

Effects of aerobic exercise on brain metabolism and grey matter volume in older adults: results of the randomised controlled SMART trial.

There is mounting evidence that aerobic exercise has a positive effect on cognitive functions in older adults. To date, little is known about the neurometabolic and molecular mechanisms underlying this positive effect. The present study used magnetic resonance spectroscopy and quantitative MRI to systematically explore the effects of physical activity on human brain metabolism and grey matter (GM) volume in healthy aging. This is a randomised controlled assessor-blinded two-armed trial (n=53) to explore exercise-induced neuroprotective and metabolic effects on the brain in cognitively healthy older adults. Participants (age >65) were allocated to a 12-week individualised aerobic exercise programme intervention (n=29) or a 12-week waiting control group (n=24). The main outcomes were the change in cerebral metabolism and its association to brain-derived neurotrophic factor (BDNF) levels as well as changes in GM volume. We found that cerebral choline concentrations remained stable after 12 weeks of aerobic exercise in the intervention group, whereas they increased in the waiting control group. No effect of training was seen on cerebral N-acetyl-aspartate concentrations, nor on markers of neuronal energy reserve or BDNF levels. Further, we observed no change in cortical GM volume in response to aerobic exercise. The finding of stable choline concentrations in the intervention group over the 3 month period might indicate a neuroprotective effect of aerobic exercise. Choline might constitute a valid marker for an effect of aerobic exercise on cerebral metabolism in healthy aging.

[Sedentary behaviour and health]. / Sedentäres Verhalten und Gesundheit--Eine selektive Literaturübersicht.

Exercise-related public health recommendations and research for increased fitness and health had long focused on vigorous exercise or the lack thereof. Recently scientific interest in possible effects of sedentary behaviour (SB) (sitting) independent of moderate-vigorous intensity exercise has been growing.We conducted a selective literature search in Pubmed and the Sedentary Research Database with the outcomes SB, risk factors, mortality and morbidity in adults. We included only reviews and systematic reviews.Observational studies suggest an association between SB and all-cause and cardiovascular, but not cancer mortality. SB also seems to be associated with diabetes and overweight/weight gain. Evidence for other diseases, such as cardiovascular diseases, hypertension, cancer, and mental diseases is limited also because of the heterogeneity and poor methodology of the -studies. Intervention studies found inconsistent evidence that SB is associated with detrimental effects on markers of cardiometabolic risk.The evidence on the detrimental effects of sedentary behaviour is decreasingly convincing with the endpoints of mortality, -morbidity, and markers of metabolic risk, in that order. Higher TV and screen time, but not total SB seems to be associated with higher all-cause and cardiovascular, but not cancer mortality. Further intervention studies are needed to establish -dose-response relationships and potentially protective effects of cardiorespiratory fitness and physical activity.

[Sporting loads to Spondylodesis of lumbar spine: The return-to-play process]. / Sportliche Belastungen nach Spondylodesen der Lendenwirbelsäule : Der Return-to-play-Prozess.

BACKGROUND: Return to play (RTP) and competition following spinal fusion is of particular importance for athletes. There is a lack of guidelines for decision making in RTP processes. OBJECTIVE: The purpose of this work was to provide a systematic review of the criteria and time of return in the RTP decision process for adults undergoing lumbar spinal fusion. METHODS: Two independent investigators searched MEDLINE using MeSH terms. Targeted outcomes were criteria for return to play decisions and total duration of the RTP process. RESULTS: So far, no prospective randomized controlled trials on RTP after spinal fusion considering inclusion and exclusion criteria are available. Five of the included studies are based on original data. Most of the identified studies are narrative reviews and, thus, exhibit low evidence levels. In addition to the narrative reviews, one observational study, two expert opinion surveys and two model development studies were found. CONCLUSION: Based on the literature research, a positive RTP decision can be made if the following criteria are fulfilled: (1) anatomical and functional healing is complete, (2) safety of the athlete and secondary subjects during training and competition is guaranteed, (3) sport-specific skills are regained, and (4) patient is psychosocially ready. The RTP process can often be successfully initiated 6 months after surgery; some patients however, will never manage the return to full-contact sports and/or sports with risk of collision.