Identification of the type of fatigue with thermography for the individualization of recovery
Knowing the type of fatigue and, therefore, improving and individualizing the recovery strategy for high-performance athletes is increasingly relevant. In the case of professional soccer players, it is a growing priority, given the tendency to increase the frequency and competitive demand. In this sense, thermography can appear in the football scene as a tool that helps improve the quality of recovery between matches.
High-performance sport and its positioning as a spectacle has made us see how various disciplines modify their traditional calendars and even rules to make them more attractive and frequent. Models such as the NBA (basketball), the ATP circuit (tennis) and, of course, professional soccer have seen how there are more and more competitions, greater physical demands and less time for training and recovery (Esteves et al.2021; Julian et al. 2021).
This change is perhaps more evident today in professional football, with the modification of match schedules, the appearance of new competitions (Nations League, Conference League, etc.) and even the change of date of the World Cup in Qatar. 2022. In addition, this is also becoming palpable in the performance data, as in the main leagues, players record more and more games per season, with increasingly higher intensity parameters (Lago-Peñas et al. 2022; Hannon et al. 2021; Zhou et al. 2020; Liu et al. 2020; Longo et al. 2019; Barnes et al, 2014) and with incomplete rest between matches.
As a logical consequence of these increasing demands, recovery strategies to reduce player fatigue and risk of injury while maintaining performance are on the rise (Field et al. 2021).
The article by Warren Gregson, Glyn Howatson and Robin Thorpe published in the September 2022 Aspetar magazine deals precisely with this issue.
Periodized recovery in high-performance soccer
A recently published systematic review with meta-analysis (Altarriba-Bartes et al. 2020) shows that the quality of post-match recovery is a key factor in maintaining elite soccer performance in the long term. Football training and competition associated with incorrect recovery lead to a reduction in performance, both physical and mental, in the elite player. Therefore, it seems logical to think that a single recovery strategy and/or a generic one-size-fits-all approach will not meet the objectives (Minnet & Costello, 2015). However, an individualized recovery in which strategies are systematically sequenced at independent time points to coincide with the source of physiological stress, along with consideration of favorable adaptation, could be a beneficial approach in professional soccer (Thorpe et al. 2017).
A periodized recovery approach linked to the traditional soccer tactical periodization model (Aquino et al. 2016) seems to be a suitable methodology to accelerate recovery and adaptation. Taking into account the available scientific evidence, Warren Gregson, Glyn Howatson and Robin Thorpe present a possible periodized recovery strategy to optimize the stress-recovery-adaptation continuum in typical elite soccer scenarios, which we will see in Figures 1 and 2.
In figure 1, we can observe a typical week in which a game is played every 7 days, which allows a 6-day recovery to be scheduled. The first 2 are dedicated entirely to recovery (DM+1 and +2), followed by 2 days of conditioning (strength in DM+3 and resistance DM-3) and the last 2 days of tapering or preparation for the match. (speed in the MD-2 and reaction in the MD-1), where the training load is considerably reduced.
In addition to compression, range of motion, and active recovery, they include cool-down and warm-up strategies at various times of the week. We emphasize that in the DM+2 a cooling or heating recovery is proposed depending on the player’s symptoms. If symptoms of muscle soreness (DOMS) are still experienced 48 hours after the game, a cool-down strategy is recommended. On the contrary, in the rest of the situations the warm-up strategies are a priority.
Figure 2 shows a congested week, in which 3 moments of competition are included. In this example, every 4 days there is a competition day (MD), as is increasingly the case in
elite football calendars. This forces the quality of recovery to be optimal to maintain good performance and prevent potential injuries.
Similarly to the example in figure 3, in figure 4 we have a recovery phase, which lasts 2 days (MD+1 and +2), followed by a day of tapering in MD-1, where there is no session. of speed, but of reaction. Therefore, the entire conditioning component is eliminated, since there are no strength, endurance or speed sessions. The goal in these microcycles is not to improve performance, but just to maintain it and avoid potential injury.
Therefore, in weeks of congestion, the quality of the recovery is even more important. The same compression, range of motion, active recovery, cool down, and warm up strategies are maintained at different times of the week. It is important to keep in mind that the MD+2, where the dilemma of a cooldown or warmup recovery was established based on the player’s symptoms, is now also the MD-2.
Thermography in decision-making for the fatigue identification
In addition to the use of thermography for the prevention of injuries, and the monitoring of certain pathologies, there is a very interesting derivative in which the temperature of the skin can be used to measure the internal load and the physiological processes associated with fatigue.
Robin Thorpe (2021) published an article last year in which he described two different types of fatigue after competition (structural damage and metabolic fatigue) and how identifying it was important in order to choose an adapted recovery strategy. In this sense, we publish in this post how the temperature of the skin can be associated with the type of fatigue, and therefore, if a cooling and heating strategy is preferable.
Delving deeper into this idea, it is interesting how Warren Gregson, Glyn Howatson and Robin Thorpe use certain thermal means to modify the physiological environment with the aim of accelerating recovery.
In figure 3A, we can observe the real case of two LaLiga soccer players with a congested match schedule. However, we appreciate certain differences in terms of their thermal behavior 48h after the game. While the first player experiences a normal reaction with an increase in temperature (structural damage) with respect to his historical one (coefficient of variation), the second has the reverse pattern, with a general reduction in temperature. He also added physical and mental fatigue due to his participation in an international tournament. More specifically, said player had a match with his national team, made a transatlantic flight (+15h of transport and time zone change of +4h) and a match with his team, all in just 4 days, as we can see in the figure 3B.
In this player, a colder global temperature can be seen, a fact that has usually been related to metabolic fatigue, as we explain in this post.
How to manage recovery strategy based on thermal response
In figure 4, we can observe the thermal profiles of a Spanish LaLiga player, through the variation coefficient metric. At a glance, identify the moments in which the player has a hot, cold and neutral thermal response. Thanks to the information provided by thermography and, in particular, by the global thermal behavior in the 48 hours after the match (MD+1 and MD+2 or +24h or +48h), a correlation can be established between the type of fatigue and the temperature. Thus, the moments in which the player experienced a global increase in his temperature, a recovery strategy with immersion in cold water was prioritized and, however, when the player had a general colder pattern, it was decided to carry out a sauna session to increase its global temperature.
The importance of recovery in performance
In order to optimize recovery in high performance, it is essential to prioritize rest, nutrition and hydration. Thereafter, recovery strategies should be considered that alleviate the specific physiological stress incurred at any point in the recovery process (Kellmann et al. 2018).
The role of assisted recovery strategy within recovery time is essential in today’s competitive landscape. In the adaptation of figure 5, we can observe the red dotted line representing the unassisted recovery, where after the match (1) the recovery time begins, which has a supercompensation peak (3) until returning to the basal state (4) . Similarly, the green dotted line assisted recovery example also experiences a supercompensation spike (2) back to baseline (4). The difference lies in the time to optimal recovery, which is considerably less in the case of assisted recovery.
Specifically in football, the most common strategies are active recovery, a structured recovery day, the extra day of rest, massage, cold water immersion therapy, sleeping medication and the provision of carbohydrates or proteins (predominantly match day and MD+1) (Field et al. 2021).
Conclusions on identification of the type of fatigue
The demand for performance in today’s football does not forgive errors in load control. To a correct planning of training sessions and matches, to which are added some minimum guidelines of nutrition, hydration and rest, assisted recovery strategies cannot be lacking to reach the optimal point.
Thermography provides objective, rapid and non-invasive information on the player’s physiological state, which may be especially relevant during the hours after the match to identify the type of associated fatigue. Knowing this information, the technical and medical teams can, in combination with other technologies and information, create an individualized recovery strategy. It is important to mention that this technology is a complement and must be associated with other tests and markers. In this way, if the player experiences a significant reduction in their body temperature, warm-up strategies can be prioritized. On the other hand, if the player is suffering from a global temperature rise, cooling strategies such as cold water immersion or cryotherapy may be best suited to optimize recovery for the player.
The key is that the day MD+2 is the one in which the authors are in doubt as to whether to use therapies to reduce or increase temperature (hot or cold), both in the standard week model and in the congested week model. Thermography provides us with the necessary information to make the appropriate decision at the right time, individually.
References
Altarriba-Bartes A, Peña J, Vicens-Bordas J, Milà-Villaroel R, Calleja-González J. Post-competition recovery strategies in elite male soccer players. Effects on performance: A systematic review and meta-analysis. PLoS One. 2020 Oct 2;15(10):e0240135.
Aquino RLQT, Cruz Gonçalves LG, Palucci Vieira LH, Oliveira LP, Alves GF, Pereira Santiago PR, Puggina EF. Periodization Training Focused on Technical-Tactical Ability in Young Soccer Players Positively Affects Biochemical Markers and Game Performance. J Strength Cond Res. 2016 Oct;30(10):2723-32.
Aspetar. Sports Medicine Journal. Targeted topic: Sports Science in Football. 2022 Sep(11). Available on: https://www.aspetar.com/Journal/articles.aspx?issueid=76
Barnes C, Archer DT, Hogg B, Bush M, Bradley PS. The evolution of physical and technical performance parameters in the English Premier League. Int J Sports Med. 2014 Dec;35(13):1095-100.
Esteves, P. T., Mikolajec, K., Schelling, X., & Sampaio, J. (2021). Basketball performance is affected by the schedule congestion: NBA back-to-backs under the microscope. European journal of sport science, 21(1), 26-35.
Field A, Harper LD, Chrismas BCR, Fowler PM, McCall A, Paul DJ, Chamari K, Taylor L. The Use of Recovery Strategies in Professional Soccer: A Worldwide Survey. Int J Sports Physiol Perform. 2021 Dec 1;16(12):1804-1815.
Hannon MP, Coleman NM, Parker LJF, McKeown J, Unnithan VB, Close GL, Drust B, Morton JP. Seasonal training and match load and micro-cycle periodization in male Premier League academy soccer players. J Sports Sci. 2021 Aug;39(16):1838-1849.
Julian, R., Page, R. M., & Harper, L. D. (2021). The effect of fixture congestion on performance during professional male soccer match-play: a systematic critical review with meta-analysis. Sports Medicine, 51(2), 255-273
Kellmann M, Bertollo M, Bosquet L, Brink M, Coutts AJ, Duffield R, Erlacher D, Halson SL, Hecksteden A, Heidari J, Kallus KW, Meeusen R, Mujika I, Robazza C, Skorski S, Venter R, Beckmann J. Recovery and Performance in Sport: Consensus Statement. Int J Sports Physiol Perform. 2018 Feb 1;13(2):240-245.
Lago-Peñas C, Lorenzo-Martinez M, López-Del Campo R, Resta R, Rey E. Evolution of physical and technical parameters in the Spanish LaLiga 2012-2019. Sci Med Footb. 2022 Mar 7:1-6.
Liu H, Wang L, Huang G, Zhang H, Mao W. Activity profiles of full-match and substitution players in the 2018 FIFA World Cup. Eur J Sport Sci. 2020 Jun;20(5):599-605.
Longo UG, Sofi F, Candela V, Dinu M, Cimmino M, Massaroni C, Schena E, Denaro V. Performance Activities and Match Outcomes of Professional Soccer Teams during the 2016/2017 Serie A Season. Medicina (Kaunas). 2019 Aug 12;55(8):469.
Minett GM, Costello JT. Specificity and context in post-exercise recovery: it is not a one-size-fits-all approach. Front Physiol. 2015 Apr 24;6:130.
Thorpe RT, Atkinson G, Drust B, Gregson W. Monitoring Fatigue Status in Elite Team-Sport Athletes: Implications for Practice. Int J Sports Physiol Perform. 2017 Apr;12(Suppl 2):S227-S234.
Thorpe RT (2021) Post-exercise Recovery: Cooling and Heating, a Periodized Approach. Front. Sports Act. Living 3:707503. doi: 10.3389/fspor.2021.707503
Zhou C, Gómez MÁ, Lorenzo A. The evolution of physical and technical performance parameters in the Chinese Soccer Super League. Biol Sport. 2020 Jun;37(2):139-145.
If you have any questions or would like to make a comment, do not hesitate to write to us. We will be happy to read you.
ThermoHuman has had the support of the Funds of the European Union and the Community of Madrid through the Operational Programme on Youth Employment. Likewise, ThermoHuman within the framework of the Export Initiation Program of ICEX NEXT, had the support of ICEX and the co-financing of the European Regional Development Fund (ERDF). 
