Blood flow restriction to improve performance and injury recovery
Blood flow restriction or BFR has become popular in the last few years in the training and physical therapy field.
A growing number of studies have reflected an increase in injuries among professional footballers in recent years. Since 2001, hamstring injuries – the most frequent kind of injury – have been increasing by 4% each year. It is calculated that a modern footballer player tends to get injured every 125 hours of playing time.
At the same time, we are also seeing an upward trend in injury frequency in amateur and lower league football, and it spikes upwards as we move up to higher leagues. The same occurs in women’s football. The causes of this phenomenon, which are scientifically proven, are multifaceted.
Currently, a football player can run between 10 and 14 kilometres during a match and almost a quarter of this distance is covered by high-intensity runs and sprints. Even up to 72 hours after such an effort, blood markers have been found in athletes indicating muscle damage and oxidative stress. Fatigue is the fundamental cause of injuries. In modern professional sports due to competitive and economic demands (i.e. the investment made in a player), there’s an urgency for the player to return back to the pitch, shortening the recovery periods after a match and even after an injury.
It has been found that the average number of injuries is greater in footballers who have four days rest after a match than in those who have six. On the other hand, the occurrence of these injuries is generally more spread out. The intensity and level of exertion required in training are more and more comparable with actual match competitive levels. In short, there is an increased intensity within the game itself, as well as the number of matches, which also has physical consequences. Today, a footballer may play 65 matches a year with their club, and in basketball, this can even reach 85, without counting international fixtures in either case.
However, there is significant variability between clubs. The greater the concentration of matches, the lower the training intensity. However, there are teams that due to their playing tactics, they have to train at a higher intensity more frequently.
There are still no studies that have clearly determined injury incidence according to a player’s field position. What has been evaluated is that hamstring injuries are the most frequent and are becoming increasingly more so. Their occurrence is associated with intrinsic, genetic, morphological or extrinsic factors such as running style, the competitive workload or the role of the player in the game. It has been observed that, in football, forwards are more likely to get injured in this muscular area.
The first preventive measure and the most important one corresponds to the sporting authorities. The saturation of matches in the calendar negatively affects the quality of the spectacle due to the evident increase in injuries that comes with it. This has some history, for example in the NBA, where there is a debate over whether to reduce the number of games at the risk of reducing income.
Long journeys affect recovery after a game. On an away trip, sleeping in unfamiliar surroundings can have an impact on the quality of the players’ sleep, which could have a negative impact on their rest. Sleep is apparently important in the prevention of injuries – although a lot remains to be studied – and it is a challenge for the future of sports medicine.
Rest, hydration and nutrition are therefore the three pillars of prevention. There are several medical recovery therapies, such as massages, saunas, ice baths, nutritional shakes, food supplements, etc., but scientific literature has not yet shown conclusive data that can help in taking general measurements on this aspect.
Another known prevention is team squad rotation, which is not always viable due to competitive pressure. However, with all of the information available, we can establish an individualised monitoring plan for each player to obtain more information that can help avoid physical injury.
In this context, it is still very complicated to establish a statistical estimate of the likelihood of injuries within a squad. However, it is possible to advance with such an estimate – despite the complexity of the phenomenon – with an information system in which a series of alerts can be established.
It is possible to monitor the external load to which a player is submitted. Distance covered, speed, accelerations and physical effort can all be measured with a GPS device. A player’s internal load is more complicated to record. It would be necessary to monitor the heart rate and perform blood analyses or urine samples to measure the different metabolite values. Currently, the Rate of Perceived Exertion (RPE) test is used; however, its reliability in elite professional athletes is dubious.
A player’s medical history can also offer decisive information. Apart from injuries caused by tackles from a rival, muscular injuries and those arising from physical exertion or burnout are more likely to reoccur.
The most difficult to quantify in a statistical model would be the player’s mental state. Stress, as shown in research carried out in Spain, is a cause of injury due to its effect on the athletes’ concentration, which in turn alters their psychomotricity. However, it is quite difficult to measure this burnout if it comes from personal problems or psychoemotional stress. Nor is it simple to quantify other kinds of demands, such as the mental effort required by a player, the pressure that comes from the team’s results throughout the season, their trajectory, or the challenges or goals that the squad have planned.
Even in a single game, stress can vary greatly for a player, depending, for example, on whether they are winning from the first few minutes or if they take the lead in the last stages of the match. These are very complicated variables in monitoring tactical demand, the demand imposed by the rival’s playing style, changes in one’s team strategy, playing with or without the ball, or changes in position that require more or less physical performance. However, all of these influence the possibility of becoming injured.
Data analysis and the conclusions that may be reached through monitoring and statistics should not alter a coach’s overall management of the team. The role of these tools is to increase the level of awareness of the coaching staff so that they can modulate training plans in accordance with the capabilities and limitations of each player.
The Barça Innovation Hub team
Are Physical Performance and Injury Risk in a Professional Soccer Team in Match-Play Affected Over a Prolonged Period of Fixture Congestion?
International Journal of Sports Medicine
Top of Form
Bottom of Form
Hamstring injuries have increased by 4% annually in men’s professional football, since 2001: a 13-year longitudinal analysis of the UEFA Elite Club injury study
Jan Ekstrand, Markus Waldén, Martin Hägglund
British Journal of Sports Medicine
Muscle injury rates in professional football increase with fixture congestion: An 11-year follow-up of the UEFA Champions League injury study
Håkan Bengtsson, Jan Ekstrand, Martin Hägglund
British Journal of Sports Medicine
Factores psicológicos y vulnerabilidad a las lesiones deportivas: un estudio en futbolistas
Aurelio Olmedilla Zafra, Carmen García Montalvo, Francisco Martínez Sánchez
Revista de Psicología del Deporte
Lesiones y factores deportivos en futbolistas jóvenes. (Injuries and athletic factors in young football players).
Aurelio Olmedilla Zafra, Mª Dolores Andreu Álvarez, Lucía Abenza Cano, Francisco J. Ortín Montero, Amador Blas Redondo
Universidad Católica de Murcia