A recent study finds that several components of executive function, including motor inhibition and attention, correlate well with soccer success in youth athletes.
With national team rosters being set as we approach the 2014 FIFA World Cup, it is easy to forget the time and energy that national and club football programs spent on developing this crop of elite athletes. Coaches and scouts scour youth soccer academies looking for young talent that may blossom into the next Messi or Ronaldo. That task is mostly subjective, but a recent study shows that components of executive function correlate well with athlete success in Dutch youth soccer (aka football) academies (Executive Functioning in Highly Talented Soccer Players, 2014. Lot Verburgh, et al.). Measuring executive function provides scouts another way of objectively assessing talent outside of commonly-prescribed physical performance tests. Furthermore, cognitive function in general has recently been recognized for its importance in athletic success.
Executive functions are comprised of higher-order cognitive functions including inhibition of behavior, attention and working memory. Executive function can be quantitatively measured with a variety of tests. It is not surprising that executive functioning is critical for soccer players. Changing dynamics on the turf require players to quickly assess changing situations, plan their next moves and execute accordingly. Working memory is essential because there are many components on the soccer field that must be taken into consideration. Finally, sustained alertness is important because a single lapse in mental focus over the duration of the 90 minute game can cost the match.
The aforementioned study tested youth soccer players in the Netherlands. The players were divided into two groups, amateur and highly talented. 84 male highly talented soccer players (average age 12) were selected from academies in the talent development programs of Dutch Premier League clubs. Admission into these academies is highly selective. The 42 amateur soccer players played in a variety of Dutch youth soccer clubs and were age-matched with the highly talented soccer players. The players’ executive function was measured with a variety of tasks requiring different cognitive functions: motor inhibition (inhibiting a visually triggered motor action in response to a second visual cue), visuospatial working memory (reproducing patterns on a 4x4 grid), attention (responding quickly and accurately to a visual stimulus).
So what components of executive function did the study find to be correlated with youth soccer success? Motor inhibition was found to be more accurate in the highly talented athletes. However, the time to react was slightly slower. This suggests that the highly talented soccer players utilize a more conservative strategy in visual motor inhibition. Attention was higher in the highly talented soccer players. However, no significant differences in visuospatial working memory were observed. The results of the study can be seen in the figure below.
However, this study leaves some questions unanswered. It has been shown in previous studies that executive function is correlated with success of adult soccer players as well. This may suggest that executive function as a youth predicts future success as a professional adult soccer player. An interesting study would be to look at where the highly talented youth soccer players end up in their future careers. We may have to wait several World Cup cycles to follow this up, although for some players the wait to get called up to a FIFA World Cup may not be long at all. Another question that can be asked is how trainable is executive function. Could the multitude of soccer situations experienced by participants in the Netherlands’ Premier League youth academies train the brain to be more adept at responding to changing situations? Research says executive function is trainable, which adds weight to this theory.
In summary, this study shows that components of executive function including attention and motor inhibition are correlated with youth soccer success, while other components, such as visuospatial memory, show no such correlation. This may add another dimension for scouts to assess the potential of youth soccer players.
Physical activity may have played a central role in the evolution of human longevity 2 million years ago. Evidence for physical activity’s role comes from its ability to reduce Alzheimer’s risk in patients who are genetically predisposed to the disease.
Even before the advent of modern medicine, humans have enjoyed longer lifespans than other mammals. The human lifespan began increasing approximately 2 million years ago. However, at this point in human evolution the human genome was homozygous for the allele ɛ4 of the apolipoprotein E (APOE) gene. APOE is a plasma protein involved in cholesterol transport and myelin integrity. Today, the ɛ4 allele is found in the genomes of 14% of the population. The ɛ4 allele is the greatest genetic risk factor for Alzheimer’s disease and has been implicated in a range of other age-related diseases including cardiovascular disease. The link between APOE ɛ4 and Alzheimers was discovered by renowned geneticist Dr. Vance, currently a professor at the University of Miami. In fact, 40-65% of patients with Alzheimer’s disease carry one or two copies of the ɛ4 allele. Thus, as human lifespans were increasing 2 million years ago, the APOE ɛ4 allele would have posed a significant genetic constraint on the aging population. That is where physical activity comes into play.
Physical activity mitigates the deleterious effects of APOE ɛ4. Researchers in a article published this month in the journal Trends in Neuroscience proposed that physical activity played a critical role in human evolution (Exercise, APOE genotype, and the evolution of the human lifespan, 2014. Raichlen DA and Alexander GE). Human longevity, they argue, came about as our distant ancestors shifted toward higher physical activity levels, reducing the disease risks of being an ɛ4 carrier. Furthermore, current lifespan constraints may reveal an incongruence between our evolutionary history and the lack of physical activity in today’s lifestyles.
APOE ɛ4 carriers develop amyloid plaques in the brain, which is a characteristic cause of Alzheimer’s. This is because the ɛ4 variant of APOE is not as efficient at catalyzing the breakdown of the peptide beta-amyloid. Beta-amyloid protein build up is what leads to amyloid plaques. In addition, APOE ɛ4 carriers often have negative age-related physiological and morphological changes in the brain such as reduced hippocampal volume (known as hippocampal atrophy).
Recent studies have demonstrated the role of physical activity in protecting APOE ɛ4 carriers from Alzheimer’s disease. A study published in Frontiers in Aging Neuroscience found that physical activity negates hippocampal atrophy in aged persons who carry an APOE ɛ4 allele (Physical activity reduces hippocampal atrophy in elders at genetic risk for Alzheimer's disease, 2014. Smith JC, et al.). In this study, the researchers used MRI to calculate hippocampal volume in elderly adults at baseline and then 18 months later. The participants were broken into 4 groups based on whether or not they were carriers of APOE ɛ4 and their physical activity level. Those who carried the APOE ɛ4 allele were labeled high risk for Alzheimer’s disease. As expected, those who did not carry the APOE ɛ4 allele saw little change in hippocampal volume, regardless of physical activity level. However, participants who carried the APOE ɛ4 allele and reported little physical activity saw a 3% decline in hippocampal volume. The surprising result is that participants who carried the APOE ɛ4 allele, but reported high levels of physical activity, saw no significant decrease in total hippocampal volume. This suggests that physical activity negates hippocampal atrophy caused by the APOE ɛ4 allele. The results are in the figure below.
Both of the articles discussed in this post highlight the importance that physical activity plays in maintaining human health. Furthermore, it reminds us that we evolved as a physically active species. The process of evolution is not fast enough to allow us to adapt to the sedentary lifestyle that has come about over the last century. A previous post in this blog also discussed exercise’s role in reducing Alzheimer’s risk by clearing reactive oxygen species. Apparently, exercise is a good means of preventing Alzheimer’s disease regardless of your genetic make-up.