How long does full recovery take following hard training or racing and what are the implications for health and performance? SPB looks at the evidence
Full and rapid recovery is essential for those who train hard and compete regularly. The sooner full recovery takes place, the sooner an athlete can engage in high-quality training or be ready to compete again – vital in sports such as multi-day events or soccer, where fixture congestion can mean two or even three matches being played in a week.
How long for full recovery?
The key question of course is how long does full recovery take? The answer of course depends on numerous factors such as how long and hard the race was, the athlete’s current fitness level, how much rest and activity takes place following a race, the recovery nutrition protocol followed (see
this article) and even your age (younger athletes tend to recover more rapidly than those who are older). The conventional wisdom is that with sufficient rest and the right nutrition, most athletes can recover from a short-ish race in a few days – maybe a week or 10 days at most. For longer races such as marathons, full recovery might take a good two to three weeks.
In reality of course, there are no hard and fast rules because so many factors are involved, including an athlete’s genetic make-up, which means that optimal recovery times are a highly variable and dependent on the individual. In more recent years, research has demonstrated that heart rate variability (HRV) can be used as a tool to help monitor physiological recovery and regeneration
(1).
Using this technology along with heart rate data accumulated during exercise, researchers studying the recovery profile of athletes completing in an ultramarathon (90km) found that heart rate responses during exercise took almost a month to return to the same initial pre-event values
(2). The researchers theorized that this long recovery period was due to the damage to the tendons and muscular system, which led to an increase in heart rate during post event exercise due to the impaired economy of locomotion. Complete recovery also involves mental recovery too, and this also takes time. In one 2011 study, researchers found that stress and recovery values after a 24-hour race (100 km) took at least two weeks to return to baseline level
(3).
Immunity and recovery
It’s well known that poor recovery leading to an overtrained state can lead to impaired immunity and an increased risk in upper respiratory tract illnesses (URTIs – coughs, colds, sore throats, influenza etc)
(4). However, research by British and Norwegian scientists on cross-country skiers suggests that recovery from a one-off long event –
eg a multi-day race – could take many weeks and also result in impaired immunity and an increase in URTIs
(5).
In this study, researchers looked at the effects of participating in a cross-country skiing stage race (the ‘Tour de Ski’), where participants race from 4-25kms everyday for a week) on subsequent illness incidence, training, and race performance. To do this, self-reported training and illness data from 44 male and female elite cross-country skiers over two or three seasons per athlete were gathered together and analyzed. In particular, the incidence of Illness, the training loads, and performances in international competitions were compared when the athletes had competed in the Tour de Ski in one season, but not in another season where the skiers had simply continued their usual training.
The findings
The first key finding was that no less than 48% of athletes reported becoming ill during or in the days immediately after taking part in the Tour de Ski! This was a 3-fold higher rate of illness when athletes had not competed in this race (see figure 1). Another finding was that in the male skiers, race performance in subsequent Olympics/World Championship races was significantly worse for at least six weeks following Tour de Ski than when the skiers hadn’t participated in the Tour de Ski. Significantly however, the female skiers seemed to fare much better; not only did they suffer lower rates of illness after the Tour de Ski, they also experienced much less of a performance decline in subsequent Olympics/World Championship races.
Figure 1: Incidence of illness in the six weeks following a Tour de Ski event(5)
Although the phenomenon of post-exercise immune suppression after prolonged and vigorous exercise is well documented
(6), the fact that almost half of the Tour de Ski athletes became ill after competing is quite surprising. One possible explanation for this is that the race takes place in mid winter when there are more upper respiratory infections doing the rounds. Also, day-to-day immunity is often lower as a result of reduced levels blood vitamin D. Low vitamin D status is strongly associated with immune dysfunction and studies show vitamin D levels in the body drop during the winter due to the lack of strong sunshine – see
this article.
Another surprising finding is that in the male athletes at least, subsequent performance was depressed for at least six weeks following the Tour, which indicate that recovery was taking a good deal longer than the athletes had expected. Together these findings suggest that (particularly male) athletes participating in hard, multi-day events need to allow ample recovery time before racing again and should (as far as possible) to maintain high levels of immunity.
More research
In a follow up study the following year titled ‘
Training-related and competition-related risk factors for respiratory tract and gastrointestinal infections in elite cross-country skiers’, the same group of researchers took a more generalized look at illnesses and infections in cross-country skiers over a period of eight seasons
(7). To do this, the researchers examined self-reported training and symptom data for 37 elite cross-country skiers from 2007 to 2015. In particular, the data was analyzed to explore the relationship between symptom incidence and duration and the following variables:
- Sex
- Performance level
- Season (winter, spring, summer, autumn)
- Training volume/intensity
- Engagement in competition
- Air travel
- Time spent at altitude
Overall, 7,016 total weeks of training performed by the 37 athletes were analysed, including 464 self-reported infection events and nearly 111,000 hours of training. The key findings were as follows:
- Athletes typically reported around three illness/infections per year (either URTIs or gastrointestinal events), with symptoms lasting an average of five days per illness/infection.
- During the winter, symptoms occurred over twice as frequently as the other seasons and also lasted longer.
- Competition and air travel both increased the risk of an illness or infection; competition by nearly threefold and air travel be nearly fivefold!
- Athletes whose training programs were more consistent and less prone to variation had higher training monotony had lower risk of symptoms.
- When they were unwell, the very best athletes – ie those who had previously won an Olympic or World Championship medal - reported shorter symptom duration compared with the less successful athletes, which resulted in significantly fewer symptomatic days per year (14 for the champion athletes vs. 22 per year for the less successful athletes).
The study authors concluded that in elite athletes, air travel and competition are major risk factors for developing acute respiratory tract infections and gastrointestinal symptoms. Meanwhile, athletes whose training programs have large fluctuations in volume and/or training load are also likely to experience such symptoms more frequently.
Although no explanation was given for the lower illness and infection rates in the champion athletes compared to the ‘merely elite’ athletes, it might have simply been this finding merely reflected the overall resilience of the champion athletes – resilience that may have partly explained their athletic success too. Alternatively, it’s possible to speculate that these athletes were paying greater attention to maintaining maximum health in order to support their training and competition – for example, ensuring optimum day-to-day diets, post recovery nutrition and maintaining optimum sleep habits.
Consistent graduated training volumes
In the study above, athletes who trained consistently without large fluctuations were found to be less likely to become ill. By contrast, the absolute amount of training load/intensity didn’t appear to affect the risk of illness, which implies that the risks relate to the way training is structured over time rather than the overall loading. Support from this notion comes from a study published earlier this year titled ‘
Training and illness characteristics of cross-country skiers transitioning from junior to senior level’
(8).
In this study, researchers tracked young skiers aged 16 transitioning to senior level over a 6-year period, and increasing their annual training volume from around 470 hours per week to 730 hours per week. Importantly, the transition took place in a very gradual and linear fashion, with 55 hours per year of extra training added (just one hour per week extra added during each of the six years). Moreover, most of the additional training hours added were low-intensity hours. In total, 145 seasons of training data (including 85,846 hours of endurance training) and 109 person-years of illness data (including 380 self-reported illness episodes) were analyzed.
The results showed that the skiers reported an average number of three illness episodes per year, averaging 5-6 days per episode (17 days of illness per year). Another finding was that there was an inverse relationship between self-reported illness days and annual training volume – ie as training volumes rose, the athletes actually averaged fewer days of illness per year. This suggests that the absolute training volumes performed do not determine illness risk of an athlete; instead it seems to be more a function of the way the training is structured and particularly when there are sudden increases in volume/intensity.
Practical implications
What do these findings mean for athletes in training and competition who want to ensure maximum recovery and stay well? Here is some advice based on the findings above:
- Full physical and psychological recovery from a marathon distance (over two hours) or longer event can take many weeks (3-6). Athletes should ensure that their post-event training during this time is light, that they get plenty of rest and sleep, and that their nutrition is high quality – see this article on nutrition and immunity. This is particularly true during the winter months when more respiratory viruses are circulating.
- If at all possible, athletes should avoid scheduling race events too close together in order to ensure a later race does not take place with a full recovery from the previous event.
- Athletes should be aware that taking flights and training at altitude significantly increase the risk of an URTI, and should therefore weigh up the benefits vs. risks, especially in the run up to an important race.
- To reduce the risk of illness, training programs should be consistent, with only very gradual increases in training volume and/or intensity. Increasing low-intensity training volume slowly by around 10-15% over the course of a year is unlikely to increase the risk of illness.
References
- Med Sci Sports Exerc. 2000 Oct; 32(10):1729-36
- J Sports Sci 1998;16:645–51
- Psychol Sport Exerc 2011;12:368–74
- Br J Sports Med. 2016 Sep;50(17):1043-52
- Scand J Med Sci Sports. 2015 Dec;25(6):846-53
- Exerc Immunol Rev. 2011;17:6-63
- Br J Sports Med. 2016 Jul;50(13):809-15
- PLoS One. 2021 May 14;16(5):e0250088