Overtraining and recovery. A conceptual model

Abstract

Fiercer competition between athletes and a wider knowledge of optimal training regimens dramatically influence current training methods. A single training bout per day was previously considered sufficient, whereas today athletes regularly train twice a day or more. Consequently, the number of athletes who are overtraining and have insufficient rest is increasing. Positive overtraining can be regarded as a natural process when the end result is adaptation and improved performance: the supercompensation principle--which includes the breakdown process (training) followed by the recovery process (rest)--is well known in sports. However, negative overtraining, causing maladaptation and other negative consequences such as staleness, can occur. Physiological, psychological, biochemical and immunological symptoms must be considered, both independently and together, to fully understand the 'staleness' syndrome. However, psychological testing may reveal early-warning signs more readily than the various physiological or immunological markers. The time frame of training and recovery is also important since the consequences of negative overtraining comprise an overtraining-response continuum from short to long term effects. An athlete failing to recover within 72 hours has presumably negatively overtrained and is in an overreached state. For an elite athlete to refrain from training for > 72 hours is extremely undesirable, highlighting the importance of a carefully monitored recovery process. There are many methods used to measure the training process but few with which to match the recovery process against it. One such framework for this is referred to as the total quality recovery (TQR) process. By using a TQR scale, structured around the scale developed for ratings of perceived exertion (RPE), the recovery process can be monitored and matched against the breakdown (training) process (TQR versus RPE). The TQR scale emphasises both the athlete's perception of recovery and the importance of active measures to improve the recovery process. Furthermore, directing attention to psychophysiological cues serves the same purpose as in RPE, i.e. increasing self-awareness. This article reviews and conceptualises the whole overtraining process. In doing so, it (i) aims to differentiate between the types of stress affecting an athlete's performance: (ii) identifies factors influencing an athlete's ability to adapt to physical training: (iii) structures the recovery process. The TQR method to facilitate monitoring of the recovery process is then suggested and a conceptual model that incorporates all of the important parameters for performance gain (adaptation) and loss (maladaptation).

Full text

Overtraining and Recovery
A Conceptual Model
Göran Kenttä and Peter Hassmén
Department of Psychology, Stockholm University, Stockholm, Sweden
Abstract
Fiercer competition between athletes and a wider knowledge of optimal train-
ing regimens dramatically influence current training methods. A single training
bout per day was previously considered sufficient, whereas today athletes regu-
larly train twice a day or more. Consequently, the number of athletes who are
overtraining and have insufficient rest is increasing.
Positive overtraining can be regarded as a natural process when the end result
is adaptation and improved performance; the supercompensation principle –
which includes the breakdown process (training) followed by the recovery pro-
cess (rest) – is well known in sports. However, negative overtraining, causing
maladaptation and other negative consequences such as staleness, can occur.
Physiological, psychological, biochemical and immunological symptoms must
be considered, both independently and together, to fully understand the ‘staleness’
syndrome. However, psychological testing may reveal early-warning signs more
readily than the various physiological or immunological markers.
The time frame of training and recovery is also important since the conse-
quences of negative overtraining comprise an overtraining-response continuum
from short to long term effects. An athlete failing to recover within 72 hours has
presumably negatively overtrained and is in an overreached state. For an elite
athlete to refrain from training for >72 hours is extremely undesirable, highlight-
ing the importance of a carefully monitored recovery process.
There are many methods used to measure the training process but few with
which to match the recovery process against it. One such framework for this is
referred to as the total quality recovery (TQR) process. By using a TQR scale,
structured around the scale developed for ratings of perceived exertion (RPE),
the recovery process can be monitored and matched against the breakdown (train-
ing) process (TQR versus RPE). The TQR scale emphasises both the athlete’s
perception of recovery and the importance of active measures to improve the
recovery process. Furthermore, directing attention to psychophysiological cues
serves the same purpose as in RPE, i.e. increasing self-awareness.
This article reviews and conceptualises the whole overtraining process. In
doing so, it (i) aims to differentiate between the types of stress affecting an ath-
lete’s performance; (ii) identifies factors influencing an athlete’s ability to adapt
to physical training; (iii) structures the recovery process. The TQR method to
facilitate monitoring of the recovery process is then suggested and a conceptual
model that incorporates all of the important parameters for performance gain
(adaptation) and loss (maladaptation).
LEADING ARTICLE
Sports Med 1998 Jul; 26 (1): 1-16
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1. Definitions, Symptoms and Time
Frame of Overtraining and its Effects
Modern-day sport, particularly at the elite level,
is fiercely competitive. With more information
now available from sports-related research, exer-
cise scientists, coaches and athletes know more
today about optimal training regimens than ever
before. Consequently, training methods have
changed dramatically.
[1,2]
Training for success has increasingly become a
balance between achieving peak performance and
avoiding the negative consequences of overtrain-
ing. Training volumes below what can be consid-
ered optimal do not result in the desired adaptation
(i.e. the greatest possible gain in performance),
whereas training volumes above the optimum may,
among other things, lead to a condition usually
referred to as the ‘overtraining syndrome’, ‘stale-
ness’ or ‘burnout’. Hard training can apparently be
the formula for both success and failure.
To date, rest (physical inactivity) is the best
known treatment for athletes who have reached an
undesirable state because of prolonged excessive
training.
[2-6]
Rest, however, is avoided by most ath-
letes since it is diametrically opposed to their in-
stinctive response when a decline in performance
occurs. Highly motivated athletes and coaches usu-
ally respond to a plateau or drop in performance
with increases in the training load.
[2,3]
Con-
sequently, it has been asserted that the greatest
training-related factor leading to negative states is
a failure to include enough recovery in the training
programme.
[1]
It follows that an imbalance be-
tween training and recovery will have mild to se-
vere negative consequences on performance.
[4]
There are no generally accepted definitions for
the terminology concerning the negative conse-
quences associated with excessively hard physical
training. Furthermore, the terms used have differ-
ent meanings in different contexts. Terms used in
connection with overtraining include overtraining
syndrome, overtrained, overstrained, overused,
overworked, overstressed, overreaching, stagna-
tion, staleness, staleness syndrome, burnout and
chronic fatigue syndrome.
[2,4,5,7-9]
In this article,
the conditions overreached and staleness are used
and are considered to be at opposite ends of an
overtraining-response continuum. An athlete fail-
ing to recover within 72 hours has presumably neg-
atively overtrained and is in an overreached state
(a short term effect). The long term effect (stale-
ness) results from more severe overtraining, is at
the other end of this continuum.
Originally, ‘burnout’ was most often used in the
literature in connection with studies of the human
service and help professions.
[10]
More recently,
Smith
[11]
extended the use of the term burnout to
include athletes. There is, however, some disagree-
ment about whether burnout really should include
‘stale’ athletes or not. Raglin
[2]
has argued that
burnout should be distinguished and viewed sepa-
rately from staleness. The main difference between
the 2 related syndromes, according to Raglin,
[2]
is
that loss of motivation (and withdrawal in severe
cases) is a central characteristic of burnout but not
of staleness. A stale athlete may still be highly
motivated to continue training and may even in-
crease the training load to compensate for a de-
crease in performance. Thus, it is important to con-
sider them separately.
Taken together, the various terms used seem,
nevertheless, to describe a single syndrome, most
often referred to in the literature as the staleness (or
overtraining) syndrome.
[2-5,6,9,12,13]
Many negative
consequences have been associated with this syn-
drome, and some of those most commonly reported
include:
• poorer performance
• severe fatigue
• muscle soreness
• overuse injuries
• reduced appetite
• disturbed sleep patterns
• mood disturbances
• immune system deficits
• concentration difficulties.
[12,14,15]
In addition, decreased submaximum and max-
imum heart rates, decreased maximum oxygen up-
take, as well as decreased submaximal and maximal
lactate levels, have also been reported in connec-
2 Kenttä & Hassmén
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tion with the negative consequences of too much
training with too little recovery.
[3,16]
Many of the
variations reported in the literature are, however,
equivocal. That is, some studies associate staleness
with increases in some specific variable, such as
heart rate, whereas other studies associate staleness
with decreases with that variable.
[3,7,14]
One possi-
ble explanation might be that different forms of
staleness exist.
Two distinct and separate types of staleness
have also been proposed, namely the sympathetic
and parasympathetic overtraining syndromes.
[3-5,7]
The sympathetic form is characterised by increased
sympathetic activity at rest while the parasympa-
thetic form is characterised by decreased sympa-
thetic activity with parasympathetic activity dom-
inating at rest and during exercise. It is believed
that the sympathetic overtraining syndrome is an
intermediate stage before parasympathetic over-
training. Markers associated with parasympathetic
overtraining are low resting heart rate and rela-
tively low exercise heart rate, while markers asso-
ciated with sympathetic overtraining are increased
resting and exercise heart rates.
[3,9,17]
Based on the aforementioned observations and
the problems identified, the aim of the remainder
of this article is to: (i) review and conceptualise the
overtraining process; (ii) differentiate between the
various types of stress that may affect an athlete’s
performance; (iii) identify factors that may affect
the athlete’s ability to adapt to physical training;
and (iv) structure the recovery process. In addition,
a new method called total quality recovery (TQR)
is suggested to facilitate monitoring of the recov-
ery process in order to reduce some of the negative
effects associated with hard physical training.
Finally, a conceptual model is presented which
incorporates all of the parameters thought to be of
importance for performance gains (i.e. adaptation)
or performance losses (maladaptation).
1.1 Markers and Symptoms of the Negative
Effects of Overtraining
The difference between positive and negative
overtraining depends on the outcome of the train-
ing process. An athlete failing to recover within 72
hours of training has presumably worked too hard
and thereby experiences negative overtraining and
can be considered to be in an overreached state.
This time frame is chosen from the elite athlete’s
perspective; if >72 hours are needed to recover,
this is definitely regarded as a failure in the training
programme. The fierce competition among elite
athletes means that a loss of training days and dis-
rupted training (i.e. forced rest for >72 hours)
would be extremely undesirable. Thus, our defini-
tion of positive overtraining conforms to the defi-
nition of the overtraining process by Raglin.
[2]
In addition, Morgan et al.
[6]
emphasised the need
to view, define and separate the cause (process) and
consequence (product) of overtraining. Raglin
[2]
later defined the training stimulus as ‘ . . . an over-
training process involving progressively increased
training to a high absolute level that is in excess of
more routine training undertaken to maintain per-
formance’. Raglin’s definition actually describes 3
degrees of training: (i) overtraining (in this case,
positive overtraining) for eliciting gains in perfor-
mance; (ii) maintenance training to remain at a cer-
tain level of performance; and (iii) undertraining
when the stress is insufficient to maintain perfor-
mance (resulting in a decrease in performance).
Negative overtraining may result in the same de-
crease in performance capacity as undertraining,
which is noteworthy. All training programmes will
fall into one of these categories. Hence, the actual
training performed (process) will determine the re-
sult (product).
Fry et al.
[7]
defined 4 major categories of symp-
toms associated with the staleness syndrome,
namely:
• physiological symptoms
• psychological symptoms
• biochemical symptoms
• immunological symptoms.
To date, studies of the staleness syndrome have
often tried to identify reliable early-warning signs
(markers) to prevent the undesired negative out-
come of hard physical training. Although observed
physiological and biochemical symptoms have
Overtraining and Recovery 3
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been effective in confirming the staleness syn-
drome, they have not been useful in preventing
it.
[18]
Other reports corroborate these findings by
stating that the value of physiological and bio-
chemical markers is still unclear.
[3,19]
One reason
for this is the inherent difficulty of distinguishing
between adaptation, a result of thoughtfully de-
vised training programmes, and maladaptation, the
point at which the benefits of adaptive training
begin to wane because of excessive training. This
is particularly evident during the course of heavy
training when some decrease in performance capac-
ity is expected. In most athletes, it is only possible
to determine whether a training cycle is adaptive or
maladaptive after it has been concluded. In some
extreme instances, this can be difficult even after
the training cycle.
A recent example illustrates the difficulty in dis-
tinguishing between adaptation and maladaptation.
A Swedish world class cross-country skier main-
tained heavy training for 20 years and never won a
gold medal in the 50km event at the national level.
He took 1 year off (only engaging in light training)
and returned to competition in 1996, when he won
his first gold medal at the age of 35. In this skier,
it might have been difficult to clearly distinguish
between adaptive and maladaptive training at any
stage during the 20-year period.
A closely related problem seems to be the un-
certainty of whether the symptoms noted precede
staleness [or occur early in the development of the
disorder (overreaching)] or are merely manifesta-
tions of the staleness syndrome.
[2]
To distinguish
between preceding markers or early-warning signs
with prognostic value and symptoms with diagnos-
tic value (when the disorder has been verified) is
extremely difficult in most applied situations.
Hence, markers and symptoms are used synony-
mously throughout this article unless otherwise in-
dicated.
Partly because of these aforementioned difficul-
ties, Shephard and Shek
[20]
concluded that psycho-
logical testing provides both easier and more effec-
tive methods for detecting the staleness syndrome
than methods dependent on various physiological
or immunological markers.
[21,22]
Four advantages
of using psychological markers to identify and
monitor the overtraining process have been re-
ported by O’Connor.
[22]
(1) Psychological changes are more reliable, i.e.
mood shifts coincide with increases and decreases
in training and are also highly replicable.
(2) Some mood states are highly sensitive to in-
creases in the training load (changes in these states
occur early on and have large effects) while others
are more sensitive to the staleness syndrome.
(3) Variations in measures of mood often correlate
with those of physiological markers.
(4) The titration of training loads based on mood
responses to overtraining appears to have good
potential for preventing staleness.
It should be noted that a recent study reported
that 1 out of 3 stale athletes did not show the antici-
pated mood response.
[23]
This suggests that mood
inventories may not always differentiate between
‘stale’ and ‘not stale’ athletes. However, there are
several limitations of this study that should be
highlighted. For example, response distortion was
not controlled for, no preseason mood assessment
was made to obtain baseline scores and mood was
only assessed 5 times. Nevertheless, this study
emphasised the need for well designed, long term
monitoring studies to determine how to prevent
staleness.
[24]
The 4 major categories of symptoms
mentioned at the start of section 1.1 all need to be
considered since they are inter-related. This in turn
lends support to the view that the staleness syn-
drome should be regarded as a psychobiological
phenomenon.
[2]
To summarise, there are various ways to classify
the different staleness symptoms and markers (i.e.
negative consequences). We suggest including all
of the consequences of negative overtraining into
the physiological, psychological, biochemical (or
neuroendocrinological) and immunological cate-
gories defined by Fry et al.
[7]
This list could easily
be extended to include behavioural and perceptual
changes, for example, but even with more catego-
ries, it remains difficult to fit some symptoms into
a single category. Some symptoms can show dif-
4 Kenttä & Hassmén
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ferent characteristics, depending on how they are
viewed. Appetite, for example, is primarily regu-
lated physiologically but it also has some psy-
chological dimensions. It seems that most of the
symptoms overlap between 2 or more categories.
Nevertheless, the 4 categories provide a good sem-
antic overview of the different bodily symptoms
that are associated with the staleness syndrome.
1.2 Long Term versus Short Term Aspects of
the Overtraining-Response Continuum
The overtraining process and its associated
symptoms may be viewed over a continuum from
short term (acute) to long term (chronic), as de-
scribed by Marion
[14]
and Kuipers.
[17]
It follows
that some borderline athletes will be difficult to
diagnose as being either ‘stale’ or ‘not stale’ when
their condition is measured on a continuum.
[8]
Thus, the border between adaptation as a result of
optimal training and the beginning stages of mal-
adaptation due to excessive training is fluid, espe-
cially during a phase of heavy training, as dis-
cussed in section 1.1.
[3]
This is why optimal
training can so easily lead to an overreached state.
Because of the overtraining-response continuum it
is also difficult to know whether observed symp-
toms are related to normal training fatigue, short
term overreaching or long term staleness.
[7]
Some
symptoms occur along the whole continuum while
others only occur at a particular stage. Interest-
ingly, a recent report asserts that fatigue and vigour
are sensitive to short term conditions while depres-
sion is more sensitive to long term conditions.
[22]
Declines in performance, which are regarded as the
hallmark of staleness,
[2]
occur together with in-
creases in perceived effort during training along
the whole continuum.
[25,26]
No consensus has been
reached regarding the extent to which performance
will decline at different stages along the contin-
uum.
[19]
The decline in performance may also vary
with overtraining across different sports, although
published data on this are very scarce. If the com-
parison is extended to cover performance decline
in, for example, all the distances for running
events, the problem becomes even more complex.
The effects of these confounding factors need to be
addressed and related to the 4 different categories
of symptoms.
Interindividual differences in recovery poten-
tial, exercise capacity, nontraining stressors and
stress tolerance may explain the different degrees
of staleness syndrome experienced by athletes
under identical training stresses.
[3]
In athletes with
less severe staleness, the markers are milder and
athletes can still train at their usual level, but at the
cost of greater difficulty to maintain any given sub-
maximal performance (e.g. running speed) and
increased perception of effort.
[27]
Hence, there is
convincing evidence to support the view that the
staleness syndrome exists on a continuum from
short term to long term effects. Consequently, gen-
eral and simplified guidelines for diagnosing stale-
ness should allow for mild through to severe symp-
toms. Milder symptoms generally predict a shorter
time for sufficient recovery from the staleness
syndrome and more severe symptoms, following
larger declines in performance, require a longer
time for recovery. ‘Stale’ athletes, for example, do
not respond well to reductions in training com-
pared with overreached athletes. As well as the
problem of setting diagnostic criteria for different
degrees of the staleness syndrome, another difficult
question is whether to look for qualitative or quan-
titative symptoms. To avoid oversimplified distinc-
tions, the whole continuum will be defined in this
article as the overtraining-response continuum.
As explained earlier in this article, overreached
and staleness are regarded as opposite extremes of
the overtraining-response continuum. This contin-
uum excludes acute fatigue that occurs immedi-
ately after exercise, acute muscular overstrain,
undertraining, maintenance training and all other
prefatigued states considered normal training re-
sponses and which are always followed by a full
recovery in the short term. The overreached state
was chosen as the starting point on the overtrain-
ing-response continuum because it is beyond this
point in the training process that negative over-
training (maladaptation) can occur if an athlete is
not carefully monitored.
Overtraining and Recovery 5
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Staleness is thus regarded as a severe long term
effect of an imbalance between the total stressors
(training and nontraining) and total recovery,
which is largely determined by the overall capacity
(stress tolerance) of the individual. Overreaching
is regarded as a far less severe, short term effect,
also resulting from an imbalance between total
stress and total recovery and determined by the
overall capacity. Both conditions are regarded as
possible products of negative overtraining.
1.3 Reasons for the Confusing Terminology
The lack of consensus regarding the terminol-
ogy of overtraining is a factor of great concern.
This was stressed by O’Connor,
[22]
who stated that
perhaps the greatest barrier to further progress in
this area of research is: (i) the existing confusion
over terminology; and (ii) the lack of established
diagnostic criteria for staleness. Other authors ad-
dress this problem by proposing the development
of an international standard with regard to term-
inology.
[7,19]
The confusion in terminology is in part due to
different theories and types of research. It is also
caused, to a considerable extent, by language bar-
riers and poor translation of reports. One reason for
poor translation is the lack of equivalent terms.
Other factors for confusion can be explained by
tradition and different cultures. European authors
have mainly used the terms overstrained, overtrain-
ing, overstrain and overtraining syndrome to indi-
cate what some US researchers refer to as staleness
or the staleness syndrome.
[22]
When studies are performed within various
disciplines, for example physiology and psychol-
ogy, differences in terminology may occur. These
differences could simply be due to the different per-
spectives in the deductive research on the psycho-
physiological overtraining phenomenon. Physio-
logical studies by Fry et al.
[7]
and Kuipers and
Keizer
[4]
use the term overload to describe the
training process, whereas psychological studies by
Morgan et al.
[6]
and Raglin
[2]
use the term over-
training. Physiologists and psychologists also dif-
fer in the use of terminology regarding the short
term to intermediate stage of the staleness syn-
drome. The term overreaching is mainly used by
physiologists,
[4,7,9]
whereas distress has been used
by the psychologists
[2,6]
to describe a less severe
state of staleness. Historically, it seems that once a
term has been established, the related studies adopt
it regardless of whether it is ultimately useful or
confusing.
2. Structuring the Overtraining and
Recovery Processes
It is evident from the studies referred to so far
in this article that there is a need to formally struc-
ture both the overtraining and recovery processes.
Only when the terminology and symptoms have
been clearly defined and incorporated into a larger
framework can a better understanding of how to
avoid training methods that may lead to staleness
be achieved. Five main areas need to be addressed
to achieve this understanding of the staleness syn-
drome.
(1) The fact that most conditions on the overtrain-
ing-response continuum are associated with per-
formance decrements and other negative conse-
quences. That is, increased training is not always
beneficial for enhanced performance.
(2) The lack of accepted tests and standard criteria
available to accurately place an overtrained athlete
on the overtraining-response continuum prohibits
clearer diagnoses. It is during periods of heavy
training (i.e. overtraining) that the most critical and
difficult diagnoses have to be made.
(3) The obvious need to develop a reliable and eas-
ily managed method to monitor training (i.e. the
breakdown process) is of the utmost concern. Such
a method could then be matched with a similar
method designed to measure recovery.
(4) The need to define the markers of recovery and
thereby extend the monitoring system to cover the
whole process of training and recovery.
(5) The need to integrate reliable markers into the
training monitoring system to prevent negative
overtraining (training that results in overreaching
and staleness).
6 Kenttä & Hassmén
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3. Factors Contributing to Staleness
The main factor leading to staleness is inade-
quate recovery (section 5). However, stress and an
individual’s capacity for training also contribute.
3.1 Categories of Stress
Lehman et al.
[3]
suggested yet another defini-
tion of the staleness syndrome which stated that
‘ . . . staleness syndrome is an imbalance between
training and recovery, exercise and exercise capac-
ity, stress and stress tolerance. Stress is the sum of
training and nontraining stress factors’. By this
definition, different types of stress contribute to the
total level of stress which may provoke, and result
in, staleness. Hopefully, this notion will encourage
researchers to consider a greater number of poten-
tial stressors in future overtraining studies. Know-
ledge of the process behind staleness would cer-
tainly benefit from identifying a larger number of
stressors and examining their interactions and
cumulative effects.
Morgan et al.
[6]
showed that the main contribu-
tor to staleness was the sport-specific stress created
by training (physiological stress). It was later dem-
onstrated that physiological stress alone can lead
to staleness.
[28]
It is unclear, however, to what ex-
tent nontraining stress factors can provoke stale-
ness. It has been suggested that the staleness syn-
drome can develop in an athlete who experiences
relatively low physiological stress, provided that
psychological and social stress factors are high.
[7]
Hence, occupational, educational and social stres-
sors should not be disregarded as potential contrib-
utors to the staleness syndrome.
[3]
Budgett
[5]
also
suggested that it is likely that only a small increase
in the total stress might suddenly and unexpectedly
elicit staleness. The onset of this staleness was
caused by an increase in psychological and/or
social stress which lead to an inability to recover
from a previously well-tolerated training pro-
gramme (physiological stress). It therefore appears
to be important to evaluate the cumulative level of
stress, and training stress might need to be adjusted
while high levels of nontraining stressors (psycho-
logical problems or social conflicts) are present in
an athlete. A preliminary study reported that per-
ceived conflicts, occurring during the past 3 to 4
days (nights), had a substantial effect on recovery
and thereby also affected performance.
[29]
In conclusion, the different stressors that may to
contribute to the staleness syndrome include psy-
chological, social and physiological training
stressors.
3.2 Capacity for Stress Tolerance
Athletes of comparable physical ability may
have different responses to a given overtraining
stimulus.
[30]
This indicates that athletes may differ
in their vulnerability to developing staleness,
which can be explained by individual differences
in psychobiological characteristics or capacity.
The same training stimulus may improve one ath-
lete’s performance, only maintain the performance
by another and cause staleness in a third ath-
lete.
[2,31]
Research findings among college swim-
mers indicate that athletes may indeed differ in
their susceptibility to staleness.
[27]
For example,
there is some evidence that, compared with indi-
viduals with normal anxiety, individuals with ele-
vated anxiety perceive and rate the intensity of a
given stressor as being greater.
[18]
Individuals who
exhibit an elevated anxiety trait could therefore be
regarded as having a lower capacity for tolerating
stress and may be more likely to develop staleness.
This gives us 3 different capacities that deter-
mine vulnerability to developing the staleness syn-
drome: psychological, social and physiological ca-
pacity.
4. Mechanisms of the Breakdown
(Training) Process
The main principle behind all physical training
aimed at improving performance is known as the
supercompensation principle.
[32,33]
This entails the
breakdown (training) process followed by the re-
covery (rest) process, which results in an ‘over-
shoot’, or rebound, in performance and adaptation.
The more intense the training, the greater the break-
down. High intensity training therefore demands
Overtraining and Recovery 7
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higher quality recovery than low intensity training.
Consequently, high intensity training also demands
a longer recovery period than low intensity train-
ing. The athlete undertaking high intensity training
would therefore benefit from high quality recovery
more than an athlete undertaking low intensity
training. Purposeful (positive) overtraining, in
contrast to negative overtraining which may even-
tually lead to staleness, is a central feature of a well
designed training programme to stimulate peak
performance. It is important, however, that the
overtraining period is followed by a period of suf-
ficient tapering, usually through a combination of
easier training and more rest units, to allow full
supercompensation.
[5]
Thus, the physiological
homeostasis must first be disturbed, whereupon
sufficient recovery must be allowed for full super-
compensation to occur. This explains why individ-
uals with superior physical fitness need to exercise
harder to improve performance than individuals
who are less fit. It also explains why overtraining,
on the one hand, can be regarded as positive when
supercompensation is the end result or, on the other
hand, negative when maladaptation occurs.
For the purposes of this review article, all single
training bouts that are sufficiently intense and/or
long enough to disturb the physiological homeo-
stasis are regarded as an overload stimulus that will
provoke and initiate the breakdown process. The
recovery and restoration of homeostasis, and also
the supercompensation that occurs if the allowed
recovery period is sufficient, is regarded as a full
recovery process. The breakdown and recovery
processes could also be viewed as one isolated pro-
cess initiated by an overload stimulus, the recovery
process being the most important phase of this sin-
gle process.
[17]
This process of breakdown and re-
covery, when initiated by a single training bout, is
referred to as a training and recovery unit. A sequ-
ence of many repeated units creates the overtrain-
ing process. It is worth noting, however, that 1 unit
alone should not cause negative consequences as-
sociated with any state of overreaching or staleness
on the overtraining-response continuum.
Coaches and athletes can choose between the
many methods of regulating and monitoring train-
ing intensity and volume. The well known methods
include the use of: (i) percentage of maximum heart
rate; (ii) percentage of 1 repetition maximum;
(iii) objective speed measures; and (iv) subjective
speed scales (1 = low speed, 3 = threshold and 5 =
maximum speed). Subjective rating scales of per-
ceived exertion,
[34,35]
for example, are frequently
used to regulate and monitor the intensity with which
the exercise is performed. Clearly, much research
effort has been devoted to developing methods to
monitor the breakdown process (i.e. through mon-
itoring training intensity), compared with the lack
of methods for measuring the recovery process.
5. The Recovery Process
5.1 Matching the Recovery Process to
the Stress
The main factor responsible for the staleness
syndrome is a lack of sufficient recovery after
heavy physical training. This makes it important to
select appropriate recovery methods that are
matched against the training stimulus.
[14]
In con-
trast to the diversity of specific methods for mea-
suring the breakdown process, very few methods
to match the recovery process against the break-
down process have been reported. Some general
and incomplete suggestions for implementing op-
timum recovery processes have been made but, in
most cases, the suggested strategies were not re-
lated to the actual breakdown process.
[7]
Another problem is that suggestions for the op-
timum recovery process are rarely differentiated as
being proactive (preventing the occurrence of
staleness) or reactive (rehabilitation from stale-
ness). This distinction is a very important one be-
cause there are considerable advantages in prevent-
ing staleness rather than merely treating it with
complete rest.
5.2 Different Types of Recovery
It has been suggested that the best way to treat
overstress (which may comprise physical over-
8 Kenttä & Hassmén
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training, psychosocial stresses or a combination of
these) is by matching the treatment with the spe-
cific symptoms.
[36]
If somatic or cognitive over-
stress occurs, it should be treated by matched in-
tervention methods. The same type of matching
principle also applies to overtraining. It is sug-
gested that overall recovery from overtraining and
psychosocial stressors will benefit from appropri-
ate, matched recovery methods aimed at the area
that is in the greatest need.
[17]
Hence, it is logical
to expect the greatest benefits to occur when over-
stress caused by social conflicts is addressed by
treating the major cause of the particular stress,
rather than treating other less important causes of
stress.
A number of authors have emphasised the need
to identify the probable causes of staleness and the
need to match these with sufficient rest, sleep, re-
laxation, nutrition or other needed interven-
tions.
[4,37-39]
Among the different approaches di-
rected towards such recovery, 4 main categories
have been identified: nutrition and hydration, sleep
and rest, relaxation and emotional support, and
stretching and active rest.
5.2.1 Nutrition and Hydration
Individuals failing to ingest sufficient carbohy-
drates to match the energy demand of heavy train-
ing have been shown to develop signs of stale-
ness.
[28,30]
A poor diet with an insufficient caloric
and fluid intake, particularly one lacking in carbo-
hydrates, will decrease the capacity to tolerate
physiological stress (training). It is well known
that the replenishment of glycogen and fluid stores
is necessary to tolerate frequent, intense bouts of
training. This might be the most important factor
in maintaining high intensity training. Fluid is nec-
essary for more than maintaining performance
capacity alone; each gram of carbohydrate requires
3g of water to bind to muscle glycogen. Insuffi-
cient fluid intake will thus inhibit performance by
allowing less glycogen to be stored. To utilise an
individual’s carbohydrate storage limit (approxi-
mately 1000g), 3000g of water is needed for it to
bind to muscle glycogen.
[40]
5.2.2 Sleep and Rest
The most frequently mentioned factor for en-
hancing recovery is the most obvious one, rest. In
this sense, rest means engaging in no physical ac-
tivity (passive recovery during the daytime) and
obtaining sufficient sleep.
[41]
5.2.3 Relaxation and Emotional Support
A few studies have shown that mental training
might help to prevent staleness.
[42-44]
This effect
has been explained by an increased recovery ca-
pacity or increased stress tolerance.
[42]
Relaxation
techniques, the use of flotation tanks, massages
and saunas have also been suggested by Marion
[14]
as proactive recovery interventions. ‘Time-out’ pe-
riods from training are recommended for prevent-
ing athletes from becoming totally preoccupied
with their sport. The learning and practice of relax-
ation and visualisation techniques by athletes is
also recommended.
[43,44]
Regeneration strategies have been widely used,
particularly in the former eastern European coun-
tries. These involve a reduction of all nonspecific
training stressors (i.e. occupational, educational,
financial and social stressors) by incorporating
rest, sleep, relaxation therapy, counselling, physio-
therapy, saunas and massage into the routine of the
athlete. Eliminating or minimising nontraining
stressors is another strategy used by sport psychol-
ogy consultants.
[5]
5.2.4 Stretching and Active Rest
Active rest, meaning low volume and low inten-
sity training, may accelerate the recovery pro-
cess.
[14]
Budgett
[5]
highlights the fact that active
rest should be provided through participation in a
different sport in which no measure of the athlete’s
performance is available. In this way, exercise is
used as a therapeutic tool to speed up recovery.
Stretching has effects similar to massage and active
rest, in that it increases the blood flow through the
muscle.
[45]
Overtraining and Recovery 9
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6. Proposed Method for Monitoring
Training and Adequate Recovery
No model cited in the current literature presents
a reliable method for monitoring both training and
recovery.
[7,46]
Elite athletes and their coaches need
a system to monitor training and recovery – a sys-
tem that incorporates reliable markers which
would be useful in preventing the staleness syn-
drome. The system must function on a daily basis
and allow quick access to information about varia-
tions in selected markers. Such as system would
present the possibility of immediately and simulta-
neously titrating the training load and the recovery
and prevent negative overtraining.
A framework for the training and recovery pro-
cess, henceforth referred to as the TQR process, has
been developed for this purpose.
[47]
The TQR pro-
cess is described in detail in section 6.2. To date,
most investigations have been focused on structur-
ing the recovery process. Some pilot research in
elite Swedish kayakers has produced positive re-
sponses from the athletes.
[47]
The main purpose of
developing this recovery system was to prevent the
occurrence of the staleness syndrome (through pro-
active recovery) and thereby optimise the balance
between training and recovery. This also reduces
the risk of overuse injuries and infections which,
in turn, helps to reduce the loss of available training
days. In other words, helps athletes to remain
healthy and capable of maintaining their training
programme. To make the TQR process user-
friendly and to relate it to the actual breakdown
process, the scale for the recovery process was
structured on the concept of the scale developed for
ratings of perceived exertion (RPE) [fig. 1].
[34,35]
The RPE scale and the concept of perceived exer-
tion have been used extensively since the scale was
first described by Borg
[34,35]
and are described in
reviews by Noble and Robertson
[48]
and Watt and
Grove.
[49]
6.1 Why Monitor Training Through Ratings of
Perceived Exertion?
Studies
[48,49]
support the hypothesis that the
sense of physical effort is best conceptualised as a
complex psychobiological construct such as RPE,
as originally proposed by Borg
[34]
(see also the
model proposed by Hassmén
[50]
). RPE is usually
accurate in estimating the intensity of an exercise
stimulus.
[18]
Athletes have also demonstrated the
ability to reproduce a certain described level of
RPE, i.e. they can self-monitor the intensity of an
exercise.
[51]
Together, these qualities facilitate a
valid and reliable method for exercise prescription
and monitoring.
Training intensity and exercise duration are the
most critical factors which, together, determine the
total physiological stress, i.e. the magnitude of the
breakdown process.
[20]
The RPE technique can be
used as a tool for accurately estimating exercise
intensity. An additional benefit of using RPE is the
resulting greater focus on the cognitive aspects
(self-awareness) of the athletes, as opposed to re-
lying on physiological cues alone. These cognitive
aspects become relevant when the athletes are re-
quired to focus on overall psychophysiological
cues to rate the perceived effort.
[48]
Since the staleness syndrome is regarded as a
psychobiological phenomenon, the method used for
Ratings of perceived
exertion (RPE)
Total quality recovery (TQR)
6
7 Very, very light
8
9 Very light
10
11 Fairly light
12
13 Somewhat hard
14
15 Hard
16
17 Very hard
18
19 Very, very hard
20
6
7 Very, very poor recovery
8
9 Very poor recovery
10
11 Poor recovery
12
13 Reasonable recovery
14
15 Good recovery
16
17 Very good recovery
18
19 Very, very good recovery
20
Fig. 1. The ratings of perceived exertion (RPE) scale for athletic
training and the total quality recovery (TQR) scale (reproduced
from Borg
[35]
and Kenttä,
[47]
respectively, with permission).
10 Kenttä & Hassmén
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monitoring exercise intensity should also consider
psychological aspects. A study demonstrated that
RPE increases significantly at given workloads in
athletes who experience staleness.
[18]
Another
study found that changes in the RPE
:
blood lactate
level ratio was a reliable predictor of staleness and
was most suitable for field settings.
[26]
Since no
reliable markers on the overtraining-response con-
tinuum have been established, the most sensitive
instrument currently available for detecting the dif-
ferent degrees of staleness is the athlete’s own
body.
[17]
Consequently, the use of RPE in applied
exercise settings could be a valuable tool in the
detection of staleness.
6.2 Why Monitor Recovery Through the
Total Quality Recovery Process?
To enable the measurement of the recovery pro-
cess, the TQR scale, which is similar to the ordin-
ary RPE scale, was developed.
[47]
The aim of de-
veloping the TQR scale was to provide a means to
measure psychophysiological recovery (fig. 1).
The use of a TQR scale makes it possible to
monitor, and potentially accelerate, the recovery
process simply by providing a more complete un-
derstanding of the actions necessary for achieving
a total recovery. The need to educate both athletes
and coaches to enhance the recovery process has
been clearly stated by other authors.
[52]
By using a
predefined scale, users will not only be more aware
of the complexities of the recovery process, they
will also easily see how actions taken translate into
an improved recovery after actual training.
The suggested TQR scale is divided into 2 sub-
scales. The first, and easiest to use in applied set-
tings, is termed the TQR perceived (TQRper)
scale. The second, more complex subscale is re-
ferred to as the TQR action (TQRact) scale. The
purpose of these subscales is to create one more
subjective (TQRper) and one more objective
(TQRact) scale, thereby integrating qualitative and
quantitative aspects of the recovery process.
The TQRper scale emphasises the athlete’s per-
ception of recovery. The athlete is asked before
bedtime to rate their recovery as an overall psycho-
physiological rating for the previous 24 hours, in-
cluding the previous night’s sleep. Directing the
athletes attention to psychophysiological cues
(mood states and bodily signals such as sensations
of soreness, heaviness, etc.) serves the same pur-
pose as in RPE, i.e. increasing self-awareness.
Since this is a highly individualised measurement,
it should be used primarily to detect intra-individ-
ual changes.
The TQRact scale grades and monitors actions
(i.e. individual proactive recovery interventions)
which, potentially, optimise and accelerate the re-
covery process. Athletes simply score their actions
and accumulate recovery ‘points’ over a 24-hour pe-
riod from the 4 main recovery categories described
in section 5.2. Nutrition and hydration allows the
accumulation of a maximum of 10 recovery points;
sleep and rest a maximum of 4 points; relaxation
and emotional support a maximum of 3 points; and
stretching and active rest a maximum of 3 points.
Thus, the maximum overall score of 20 points is
equal to the highest ranking on the TQRact scale.
Complete and accelerated recovery decreases the
total time taken for the recovery process. Conse-
quently, an athlete can tolerate more frequent and
more intensive training. Theoretically, another ath-
lete could eventually have a TQRact score which
is beyond the lower limit of the actual scale (i.e <6).
In practice, this would happen only in a case of
badly mismanaged recovery.
Athletes accrue recovery points over a 24-hour
period. The points are determined using stand-
ardised, individual calculations described in a spe-
cially designed TQR manual. The manual serves as
a guideline to the athlete on how to earn recovery
points. Recovery points are divided into the 4 dif-
ferent categories discussed above to direct the ath-
lete’s attention towards important recovery ac-
tions. Points are distributed among the recovery
actions according to their degree of importance for
the recovery process as well as accounting for the
practical limitations that occur in field settings. It
is easy to modify the criteria in the TQR manual so
that they meet the demands of both the individual
and the specific sport. The described manual was
Overtraining and Recovery 11
 Adis International Limited. All rights reserved. Sports Med 1998 Jul; 26 (1)

developed primarily to meet the needs of elite se-
nior athletes (men and women) undertaking intense
training for endurance sports. It can be adapted,
however, for other groups also at risk for develop-
ing the staleness syndrome.
A general practical recommendation for ensur-
ing that an athlete’s recovery is adequate is that
both the TQRact and TQRper ratings should, pref-
erably, be at least equivalent to the actual training
stress (RPE rating). This is particularly important
when training becomes more intense because the
recovery process is believed to be accelerated by
proactive recovery actions. Proactive recovery
actions are considered to provide a higher quality
recovery compared with passive rest. A lower train-
ing intensity does not require the same high quality
of recovery but, even after days of light training,
there is a recommended minimum level of recovery
[TQR 13 (reasonable recovery)] which athletes
must attain.
Another practical implication to consider is the
comparison of TQRact and TQRper. When an ath-
lete has been taking full and complete measures for
the recovery process and rates significantly lower
on the TQRper compared with the TQRact scale,
this is an early-warning sign that there is an imbal-
ance between training and recovery. The report by
Fry et al.
[12]
lends some support to the suggestion
that an athlete’s perception of recovery can be used
as a potential marker for staleness: they observed
that a group of athletes with the staleness syndrome
experienced a decreased perception of recovery
compared with ‘nonstale’ athletes. Further support
is provided in other articles
[4,17]
which suggest that
perceived insufficient recovery is a marker for de-
tecting the staleness syndrome. This framework
(TQR process) also allows the study of the associ-
ations between training intensity (RPE), recovery
(TQR), variations in performance and other phys-
iological markers such as immune function, muscle
glycogen, cortisol, etc. The study of these associa-
tions might permit coaches and athletes to optimise
the balance between training and recovery and
achieve the best possible performances.
So far in this article, only the training and recov-
ery processes have been structured. The next step
is to integrate these 2 processes into the overall
context of overtraining and recovery, rather than
examining them separately. This will improve our
understanding of the results of athlete monitoring
and the correlation between training stress (pro-
cess) and the result of training (product).
7. Conceptual Model for Overtraining
and Recovery
One of the few questionnaires encountered in
the literature that attempts to address the full com-
plexities of stress and recovery was developed in
Germany by Kallus.
[29]
The Recovery-Stress-
Questionnaire (RESTQ) was developed to measure
various areas of stress and various areas of recov-
ery activities.
[29]
The stress and recovery activities
are assessed simultaneously by the RESTQ. The
result of the RESTQ provides an answer to the
question ‘How are you?’, which is similar in nature
to the actual state of stress determined by the stress-
recovery balance. The RESTQ is based on the
assumption that an accumulation of stress from
various aspects of life leads to an altered overall
state of stress, at least when there are insufficient
opportunities for recovery. Although the RESTQ
was developed to measure stress and recovery in a
general sense, and not particularly in regard to stale-
ness, it provides support for the conceptual model
developed here for overtraining and recovery.
The conceptual model described below is an at-
tempt to view the complex overtraining and recov-
ery processes in their full context. It aims to in-
crease understanding of the different parameters
which interact and determine the full process un-
derlying performance improvements (adaptation)
and performance decrements (maladaptation). This
is of great value for coaches, athletes and trainers
alike because it can be used as a guideline for mon-
itoring training and recovery, i.e. for tailoring the
perfect training programme.
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7.1 Process of Overtraining and Recovery
The total process of overtraining and recovery
and the factors involved could be viewed as being
controlled by forces which are both additive and
interactive. The additive and interactive effects de-
termine the final configuration of the total process.
The total process is determined by 3 major subsys-
tems, each consisting of 3 components: a specific
stress, a specific capacity and a specific recovery. The
sums of these components determine (1) the actual
magnitude of total stress, (2) the actual overall ca-
pacity, and, finally, (3) the actual total recovery.
7.1.1 Actual Magnitude of Total Stress
Physiological stress (i.e. training) is the most
central aspect of the staleness syndrome. Forms of
stress such as illness and the use of drugs or med-
ications are not of primary interest in the model.
Psychological stress and social stress require more
attention in the body-mind performance context.
Psychological stress is defined here as intra-
individual stress arising from internal stressors;
this may, for example, stem from a perceived
imbalance between athletic expectations and an
athlete’s performance capabilities. Social stress is
defined as the result of interactions with other peo-
ple. Social stressors may arise from home life,
friends, colleagues at work, coaches and competi-
tors, as described by Rushall.
[53]
Psychological and
social stress, in conjunction with physiological
stress, determine the actual magnitude of the total
stress.
7.1.2 Actual Overall Capacities For Stress
The actual capacities for stress determine how
much stress can be tolerated by an individual.
Three major capacities have been identified which
consist of various numbers of subcapacities. Aero-
bic and anaerobic capacities (both energy produc-
tion capacities), and general strength, specific
strength and technique together, are the neuromus-
cular capacities. The capacity for psychological
stress comprises the level of self-confidence, ca-
pacity to cope with anxiety, attentional capacity,
motivational level, attitude control, positive energy
(positive mental health) and visualisation capacity.
The capacity for social stress consists of the ability
to create, handle and maintain relationships with
others. All of the subcapacities within a specific
category interact to determine the total capacity of
an individual for that category of stress.
7.1.3 Actual Total Recovery From Stress
Recovery processes can also be differentiated
into various subsystems and can be related to dif-
ferent types of stress.
[29]
The aim of each recovery
activity should be to restore homeostasis and allow
the adaptation of the individual to the stress(es). It
is not possible to establish a full recovery until
overall psychobiological homeostasis is attained.
Therefore, all of the recovery processes need to be
taken into account. Physiological recovery in rela-
tion to nutrition and hydration, sleep and rest, and
stretching and active rest has been described in
section 5.1. Psychological recovery is achieved
through relaxation and emotional support. Finally,
recovery from social stresses can be achieved only
by interaction of the athlete with close friends or
family members (social support).
Adequate recovery is dependent on the specific
type of stress and the individual’s capacities. The
aim of monitoring training and adequate recovery
in the elite athlete is to reach a balance in the zone
where training yields optimal increases in perfor-
mance. So far, this zone has been poorly de-
fined.
[17]
Therefore, we suggest that this optimal
zone be defined as the adaptation threshold. Theor-
etically, the adaptation threshold is the dynamic
‘breaking point’ where adaptation suddenly (i.e.
within a short time frame for athletes near this
threshold) becomes maladaptation. Together, re-
covery, stress and capacity can be viewed as 3 vari-
ables affecting the adaptation threshold. Thus, the
need to identify the individual’s dynamic threshold
can be seen as the overall goal in monitoring train-
ing and recovery. As a consequence, discussions
about which training regimens are good (adaptive)
or bad (maladaptive) are incomplete without also
considering the characteristics of the individual
Overtraining and Recovery 13
 Adis International Limited. All rights reserved. Sports Med 1998 Jul; 26 (1)

and the recovery process together with the psy-
chosocial stressors.
To achieve the best results from each and every
training session therefore demands consistent
monitoring and intelligent decision-making. This
occurs when the athlete responds to their day-to-
day condition, or state, and as a consequence selects
the most appropriate training session at that time.
It is worth noting that a specific training stimulus
may improve the athlete’s performance at one point
in time or merely maintain performance or cause
staleness at other times. As discussed in this sec-
tion, it is almost impossible to judge beforehand
whether a given training schedule will have nega-
tive or positive consequences for all athletes. In
this regard, optimal training can be regarded as an
ongoing process of the ‘total quality management’
of training and recovery (RPE versus TQR).
8. Matching Stress, Capacity
and Recovery to Improve the
Adaptation Threshold
As mentioned earlier, optimising the recovery
process enables the athlete to tolerate more fre-
quent and more intense training and still respond
positively. This corresponds to improving the ad-
aptation threshold. Optimising the recovery and
increasing the stress tolerance (i.e. capacity for
stress) of an athlete are 2 different approaches, both
of which should increase the dynamic adaptation
threshold.
The matching principle can be applied in 3 dif-
ferent ways to prevent staleness (enhancing the ad-
aptation threshold).
(1) Recovery must be matched with the specific
stress or stressors.
(2) Training must be directed at improving specific
capacities, which will in turn increase the specific
(matched) stress tolerance. Improved coping skills
will, for example, increase the overall psychologi-
cal capacity and, eventually, this is believed to in-
crease the overall stress tolerance.
(3) Psychological and social stressors must be min-
imised to better utilise the available resource of stress
tolerance for adapting to the physiological stress.
For obvious reasons, the possible fourth option
of reducing the training stress to a minimum is not
feasible for competitive athletes.
The final assessment of all of the factors in-
cluded in the model can be made when all of the
available cues from the sociopsychophysiological
process and the responses (symptoms and markers)
have been evaluated (fig. 2). Individual baseline
measurements for all of the considered overtrain-
ing markers are necessary for correct assessments
of intra-individual changes. The final assessment
should answer the most critical question for every
athlete, ‘Is it OK to continue my training sched-
ule?’ (i.e. will the result of my training lead to ad-
aptation or maladaptation within my desired time
frame?). By assessing individual differences in
total stress, total capacity and total recovery, it is
easier to understand why individuals respond dif-
ferently to a particular training stimulus. This
might even help to explain why some individuals
seem to differ in their vulnerability to developing
staleness. However, instead of discriminating be-
tween athletes on a basis of static vulnerability, it
is better to use the term individual adaptation
threshold, since this concept is dynamic and allows
for change, or improvement by training.
9. Future Directions
Few studies have focused on self-assessments
by athletes for monitoring training and recovery.
[8]
The conceptual model proposed here can be used
as a framework for such studies. Empirical testing
of the model, and all of the variables included, is
of the utmost importance for the future develop-
ment of improved or more sensitive monitoring of
the whole training process, that is, with a focus on
the relative contributions from different variables
(physiological, psychological, biochemical and
immunological). Interdisciplinary studies to incor-
porate knowledge from other related subdisciplines,
such as sports medicine, education sciences and
biochemical sciences, are also warranted. It is fur-
ther suggested that the overtraining model de-
scribed in this article will make it easier for endur-
ance athletes to monitor and balance the total
14 Kenttä & Hassmén
 Adis International Limited. All rights reserved. Sports Med 1998 Jul; 26 (1)

training and recovery process. The model thereby
enables the user to examine problems either sepa-
rately (e.g. biochemical, physiological, psycholog-
ical, nutritional, etc.) or by adopting a holistic per-
spective. It is suggested that the staleness
syndrome can only be fully understood in this
larger context. The proposed model also highlights
the potential influence of factors primarily related
to recovery, so far left uninvestigated by overtrain-
ing studies, and may encourage researchers to turn
their attentions to these.
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Psychological stress/capacity
Recovery
Short
term
effects
Long
term
effects
Psychological
Physiological
Neuroendocrine
Immunological
Process,
stress or
stimuli
Product,
result or
response
Final
assessment
Social stress/capacity
Recovery
Physiological stress/capacity
Recovery
Four categories of
multi-symptomatic
markers of the staleness
syndrome
Overtraining-response
continuum
Athletic balance
Adaptation
Maladaptation
Performance
Fig. 2. An overview of the whole overtraining and recovery process.
Overtraining and Recovery 15
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Correspondence and reprints: Dr Göran Kenttä, Department
of Psychology, Stockholm University, S-106 91 Stockholm,
Sweden.
E-mail: gka@psychology.su.se
16 Kenttä & Hassmén
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