Summer is here, which means the end of many football competitions and regular football being played (League, Champions, Copa del Rey, etc.). The so-long awaited holidays have arrived, a period (usually 4-6 weeks, although it may be less) in which football players significantly reduce their training loads – often putting a halt to training entirely, which is often paired with greater freedom when it comes to nutrition. However, although a physical and mental rest period is a must before facing the next season, this period can also have significant negative consequences on the performance of football players, which is known as ‘detraining.’
We know the loss of physical capacities resulting from a reduction in training loads as ‘detraining.’ 1 It has been widely described in the scientific literature that pausing training for several weeks can negatively affect athletes’ performance. For example, almost 30 years ago, a study observed that a group of runners who stopped training for two weeks suffered a decrease in their maximum oxygen consumption of 5%. In addition, they resisted an incremental stress test with a 10% reduction of time. 2 Therefore, even short periods without training can have significant consequences. That is why, during the holidays, they include a transition period to the new season. Thus, after a short period of stopping training entirely, another period is generally included. The athlete progressively increases the training loads to improve their physical condition- or reduce its deterioration-and avoid injuries in their return to competition.
However, although the evidence has grown a lot in recent years, it is still unknown what real effects holidays have on football players. That is why a recent systematic review published in the prestigious journal Sports Medicine has tried to summarize the scientific evidence in this regard. 3 After conducting an extensive search, the authors found 12 studies conducted on football players that evaluated periods of detraining or holidays lasting between 2 and 12 weeks. The analysis of these studies showed that holiday periods associated with no training result in increased body fat and a decline of maximum oxygen consumption, performance in an intermittent test such as the Yoyo, the vertical jump, and the ability to perform repeated sprints. On the other hand, the authors observed that if the athletes participated in a training program adapted to this period during the holidays, there was a significant reduction in the deterioration of the maximum oxygen consumption and the ability to perform repeated sprints compared to quitting training entirely. However, the increase in body fat and the loss of performance in the vertical jump and sprint were similar whether they performed a training program or not.
Therefore, these results reflect the significant consequences that holidays can have on football players’ shape, producing adverse effects on body composition and performance. These effects can, in turn, increase the risk of injury at the beginning of the new season, consequently, it will be essential to make an adequate progression of the training loads and start the competitive period gradually.
Additionally, according to this meta-analysis, participating in adapted training programs during the holidays could mitigate detraining to some extent. However, as noted by the authors, most of the programs applied in the scientific literature have failed to avoid the adverse effects of detraining. These results, therefore, encourage the implementation of training programs during the holidays. Still, optimising these programs is necessary to reduce the consequences of detraining as much as possible, allowing athletes to rest physically and mentally. In this sense, to avoid detraining, the objective should be to maintain or even increase the intensity of the workouts, even if their volume is decreased. Therefore, several studies regarding football players have observed that if during a two-week detraining period, the training volume is reduced by 30% but several high-intensity sessions are included, it is possible to avoid negative adaptations and achieve performance improvements. 4,5 For this reason, during the holidays, it might be advisable to prioritise high-intensity and strength training to return to the new season in the best possible conditions.
Although holidays are a physical and mental must have, they can have significant negative consequences on football players’ performance and body composition; this, in turn, would influence injury risk and performance at the start of the new season. It is necessary to implement adapted training programs during these periods, which should maintain the intensity of the workouts (for example, through high-intensity interval training sessions or strength) despite a substantial reduction in their volume.
Pedro L. Valenzuela
- Mujika I, Padilla S. Detraining: Loss of training induced physiological and performance adaptation. Part I. Short term insufficient training stimulus. Sport Med. 2000;30(2):79-87. doi:10.2165/00007256-200030020-00002
- Houmard JA, Hortobagyi T, Johns RA, et al. Effect of short-term training cessation on performance measures in distance runners. Int J Sports Med. 1992;13(8):572-576. doi:10.1055/s-2007-1024567
- Clemente FM, Ramirez-Campillo R, Sarmento H. Detrimental Effects of the Off-Season in Soccer Players: A Systematic Review and Meta-analysis. Sport Med. 2021;51(4):795-814. doi:10.1007/s40279-020-01407-4
- Christensen PM, Krustrup P, Gunnarsson TP, Kiilerich K, Nybo L, Bangsbo J. VO2 kinetics and performance in soccer players after intense training and inactivity. Med Sci Sports Exerc. 2011;43(9):1716-1724. doi:10.1249/MSS.0b013e318211c01a
- Thomassen M, Christensen PM, Gunnarsson TP, Nybo L, Bangsbo J. Effect of 2-wk intensified training and inactivity on muscle Na +-K+ pump expression, phospholemman (FXYDI) phosphorylation, and performance in soccer players. J Appl Physiol. 2010;108(4):898-905. doi:10.1152/japplphysiol.01015.2009