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Symptoms of Overtraining in Resistance Exercise: International
Cross-Sectional Survey
Clementine Grandou, Lee Wallace, Aaron J. Coutts, Lee Bell, and Franco M. Impellizzeri
Purpose:To provide details on the nature and symptomatic profile of training maladaptation in competitive resistance-based
athletes to examine whether there are symptoms that may be used as prognostic indicators of overtraining. Identifying prognostic
tools to assess for training maladaptation is essential for avoiding severe overtraining conditions. Methods:A Web-based survey
was distributed to a cross-sectional convenience sample of competitive athletes involved in sports with a significant resistance-
training component. The 46-item anonymous survey was distributed via industry experts and social media from July to August
2019. Results:The final sample included 605 responses (completion rate: 84%). About 71% of the respondents indicated that
they had previously experienced an unexplained decrease in performance. Among those, the majority reported a performance
decrement lasting 1 wk to 1 mo (43.8%). General feelings of fatigue were the most frequent self-reported symptom of
maladaptation. Acute training maladaptation, lasting <1 mo, was also accompanied by symptoms of musculoskeletal aches and
pain. In the majority of cases (92.5%), training maladaptation was accompanied by additional nontraining stressors. A greater
proportion of the respondents with more severe maladaptation (>4 mo) were training to muscle failure. Conclusion:The results
from this study support the multifactorial nature of training maladaptation. The multidimensional nature of fatigue and individual
variability in symptomatic responses precludes definitive prognostic symptoms or differential diagnostic factors of functional/
nonfunctional overreaching or the overtraining syndrome in resistance exercise.
Keywords:fatigue, overreaching, resistance training, strength training
Resistance training is often undertaken by athletes who strive
to improve muscle strength, hypertrophy, and power.
1
It is well
accepted that resistance training can enhance an athlete’s ability to
perform general sporting skills (eg, jumping and sprinting), which
may result in superior competition performance during sport-
specific tasks.
2
However, designing an optimal resistance-training
program is a complex process that involves the careful manipula-
tion of several training variables (eg, training load, volume,
frequency, rest periods, and exercise selection).
3
Intensified resis-
tance training in combination with inadequate recovery can result
in a decline in performance with or without related physiological
and/or psychological signs and symptoms.
4
Resulting maladaptive
conditions may include functional overreaching (FOR), nonfunc-
tional overreaching (NFOR), or the overtraining syndrome (OTS).
The well-accepted definitions of Meeusen et al
5
suggest that the
differential diagnosis of these conditions is based on the time
required for performance restoration. Additionally, it has been
suggested that complete performance restoration may not ever
be possible with the OTS.
2
However, as current diagnostic criteria
has been established through the study of overtraining in endurance
activities, it is unknown whether these definitions are compatible
with such conditions in resistance training.
The prevention and early diagnosis of maladaptive conditions
are critical, as there are no firmly established therapeutic agents
(other than rest) capable of reversing the detrimental effects of
overtraining.
5
Many previous studies have searched for prognostic
and diagnostic markers that may be used to determine the onset or
presence of overtraining (for review, see Meeusen et al
5
). It has
previously been established that considerable variability exists in the
way that individuals respond to resistance-exercise stress.
6
Contex-
tual factors and nontraining stressors, such as environmental, physi-
cal and/or emotional stressors, including insufficient calorie intake,
pressure to perform, inadequate nutrition, insufficient sleep, or
excessive socioeconomic concerns, may result in large interindivid-
ual variability of stress symptoms.
7,8
In a recent study designed to
examine overtrained athletes, Cadegiani and Kater
9
identified a
unique combination of clinical and biochemical manifestations in
each individual affected. Furthermore, this study demonstrated a
relationship between additional nontraining stressors or contextual
factors and susceptibility to overtraining. Additionally, in a synopsis
of previous literature, Fry et al
10
listed 84 major symptoms and
manifestations of overtraining in a variety of sports. Determining
which signs and symptoms to monitor from such an extensive list
continues to challenge both coaches and athletes.
Estimates of the prevalence of overtraining have varied widely
depending on the authors’definition of overtraining, the popula-
tion, and the study methodology. It has previously been suggested
that endurance- and resistance-trained athletes respond differently
to training stress.
4
Early studies implied that athletes involved
in primarily anaerobic activities may be more susceptible to over-
training than endurance-based athletes.
11,12
However, much of the
early overtraining literature in resistance exercise was limited to
anecdotal accounts, with an inconsistent use of definitions making
quantification of prevalence difficult.
12
Additionally, the majority of
previous overtraining studies have included only male participants.
13
At present, information concerning overtraining prevalence, poten-
tial mechanisms, and symptomatology in resistance-trained athletes
is scarce.
Many previous studies that have investigated the mechanisms
and manifestation of overtraining in resistance exercise have failed
Grandou, Wallace, Coutts, and Impellizzeri are with the Human Performance
Research Centre, University of Technology Sydney, Sydney, NSW, Australia.
Bell is with the Academy for Sport and Physical Activity, Faculty of Health and
Wellbeing, Sheffield Hallam University, Sheffield, United Kingdom. Grandou
(Clementine. Grandou@uts.edu.au) is corresponding author.
1
International Journal of Sports Physiology and Performance, (Ahead of Print)
https://doi.org/10.1123/ijspp.2019-0825
© 2020 Human Kinetics, Inc. ORIGINAL INVESTIGATION
to appropriately establish FOR, NFOR, or OTS (for review, see
Grandou et al
13
). Therefore, the objective of the present exploratory
study was to identify possible prognostic symptoms of training
maladaptation in resistance exercise. Determining the point at
which training becomes maladaptive is of key practical significance
for athletes and coaches. At present, the correct diagnosis of
maladaptive conditions can only be made retrospectively. There-
fore, if prognostic symptoms of overtraining can be identified,
remedial reductions in training stress can be implemented, and
training maladaptation may be avoided.
Methods
An open international survey was used to identify the symptoms of
unexplained training maladaptation amongst competitive athletes in
resistance-based sports. Detailed methods according to the Check-
list for Reporting Results of Internet E-Surveys (CHERRIES)
14
are
available in Supplementary Table S1 (available online). This study
was approved by the Human Research Ethics Committee of the
University of Technology Sydney (ETH19-3898).
Survey Development
An anonymous survey was developed on REDCap (Research
Electronic Data Capture software, version 8.11.3; University of
Technology Sydney, Sydney, Australia), a secure Web application
for building and managing online surveys. The survey was created
by the authors in conjunction with a multidisciplinary team of
experts in overtraining and resistance training, who provided
feedback. In order to establish the content validity and reduce
response bias, the first draft of the survey was piloted with a
convenience sample of 24 athletes who participated in resistance-
based sports. Based on the resulting feedback, the survey was
modified to improve its content, clarity, readability, and overall
quality. The revised survey was further piloted on a focus group of
6 participants (industry experts and athletes). Based on feedback
from the pilot testing, the content and format of the survey was
further refined. Finally, the authors completed a heuristic evalua-
tion to establish the usability of the survey interface on various
devices (PC, Macintosh, iPhone, and Android).
The final survey consisted of 46 items distributed among 6
sections: (1) demographic information, (2) strength, (3) perfor-
mance, (4) training, (5) symptoms, and (6) recovery (Table 1). The
survey concluded at section 3 for subjects who indicated that they
have never experienced an unexplained decline in performance.
Both open-ended and dichotomous questions were included
throughout the survey. In order to avoid acquiescence bias, the
respondents were not prompted by preloaded questions asking if
they did/did not experience a particular symptom. Such questions
increase the likelihood of participants falsely reporting the presence
of a symptom that they may not have experienced. Rather, the
respondents were required to self-report their symptoms in open
text boxes. The survey was available in 4 languages (English,
Italian, Portuguese, and Spanish). Native speakers assessed the
validity of each translation based on the original English survey.
Sample Selection and Administration
A voluntary convenience sample of competitive athletes involved
in sports with a resistance-training component were recruited.
Eligible sports were categorized into “resistance exercise only”
sports (powerlifting, bodybuilding, weightlifting, and strongman)
and “resistance exercise combined”sports (CrossFit, rugby, sprint-
ing, hurdles, long/triple/high jump, shot put, javelin, discus, and
pole vault). Collectively, the respondents will be referred to as
“resistance-based athletes.”Participants must have competed in
their respective sports; however, no restriction was placed on the
level of competition (ie, club to international level athletes).
Respondents were recruited through various means from July
to August 2019 to obtain a sample of approximately 1000 re-
sponses. The primary methods of recruitment were through emails
distributed to industry experts in relevant sports/disciplines and
by direct sharing of a survey recruitment flyer on social media
(Supplementary Figure S1 [available online]). In order to avoid
sampling bias, terms related to “overtraining”and “overreaching”
were not used in the survey advertisement or until section (6) of the
survey, thus reducing the likelihood that the resulting sample
overrepresents individuals who have strong opinions or experi-
ences with overreaching and overtraining.
Statistical Analysis
Statistical analysis of the anonymous data set was conducted
using SPSS (version 25.0; IBM Corp, Armonk, NY). Missing
data checks were conducted to confirm data integrity. The fre-
quencies were calculated for the respondents’demographic and
training characteristics, and the respondents were categorized
according to their respective sport/discipline (resistance exercise
only and resistance exercise combined). The proportion of ath-
letes who reported that they had previously experienced an
unexplained decrease in performance were tabulated. Bivariate
statistics (chi-square analyses) were used to determine whether
experiences of training maladaptation varied by training history
and/or training style.
Results
Among the 961 online survey views, 760 responded (84% com-
pletion rate; Figure 1). Following the exclusion of recreational
athletes and those who were involved in noneligible sports, the final
sample size included 605 responses. Overall, 70.9% of the parti-
cipants indicated that they had previously experienced an unex-
plained decrease in competition performance (Table 2). A majority
of the respondents (76.5%) were involved in resistance exercise
only sports (powerlifting, weightlifting, and bodybuilding). The
demographic characteristics of the participants are summarized by
sporting category in Table 3.
Among the participants who indicated that they had previously
experienced an unexplained decrease in performance, 70.9% were
indicative of acute maladaptation indicating possible acute fatigue,
FOR or NFOR (<1 wk = 26.8%, 1 wk–1 mo = 43.8%; Figure 2).
Only 17.8% of the responses were reflective of chronic training
maladaptation indicating possible NFOR or OTS (1–3mo=
13.1%, >4 mo = 4.7%). No interaction effect was found between
how many years the participants had been training and unexplained
decreases in performance (P= .26). However, the findings showed
that a greater proportion of the participants with more severe
training maladaptation (>4 mo) reported training to muscular
failure (Figure 3). The majority of the participants who had
experienced a decline in performance also reported experiencing
additional stress outside of training (92.5%). The most commonly
reported stressor was work (25.5%), followed by personal life
(23.2%) and external factors, such as dieting/negative energy
balance (22.9%) (Table 4).
(Ahead of Print)
2Grandou et al
Table 1 Survey Instrument
Field Answer choice
1. Demographics
Country Country dropdown
Gender 1. Male
2. Female
3. Other
Age, y Numerical
Body weight, kg Numerical
Height, cm Numerical
What sport or discipline do you compete in? 1. Weightlifting
2. Powerlifting
3. Strongman
4. Bodybuilding
5. Sprinting
6. Hurdles
7. Long jump
8. Triple jump
9. High jump
10. Shot put
11. Javelin
12. Discus
13. CrossFit
14. Rugby union
15. Rugby league
16. American football
17. Pole vault
18. Other
If “other,”please specify Open
How many years have you been training in your sport? Numerical
What is the highest level you have competed at? 1. Club
2. Regional
3. State
4. National
5. International
6. Other
2. Strength
Load SQUAT: What is the maximum weight you have lifted for a given number of repetitions?
(ie, 100 kg for 1RM or 75 kg for 3RM, etc), kg
Numerical
Repetitions? Numerical
Load BENCH PRESS: What is the maximum weight you have lifted for a given number of
repetitions? (ie, 100 kg for 1RM or 75 kg for 3RM, etc), kg
Numerical
Repetitions? Numerical
3. Performance
Have you ever experienced an unexplained decrease in performance? 1. Yes
2. No (survey termination if “No”)
4. Training
How many times have you experienced this? 1. Once
2. Twice
3. 3 or more times
Please answer the following questions in reference to your most severe case (if more than once)
How was your performance affected? 1. Decreased strength
2. Decreased running speed
3. Blunted hypertrophy
4. Increased perception of effort while training
5. Decrease in sport performance (eg, jump
height, throwing, and sprint)
6. Other
If “other,”please specify Open
(continued)
(Ahead of Print) 3
Table 1 (continued)
Field Answer choice
How long did the decrease in performance last? (ie, when did your performance return to normal?) 1. <1wk
2. 1 wk–1mo
3. 1–3mo
4. >4mo
Leading up to the decline in performance, how many times per week were you performing
resistance training?
Open
What was the average duration of each resistance training session? 1. <1h
2. 1–2h
3. >2h
Leading up to the decline in performance, were you also performing technical/skill training? 1. Yes
2. No
Leading up to the decline in performance, were you also performing metabolic and/or
conditioning training?
1. Yes
2. No
Which option best describes the INTENSITY of resistance training you were performing
at the time you experienced the decline in performance?
1. heavy loads to muscular failure
2. heavy loads without muscular failure
3. light loads to muscular failure
4. light loads without muscular failure
Which option best describes the VOLUME of resistance training you were performing
at the time you experienced the decline in performance?
1. high repetitions, high sets
2. high repetitions, low sets
3. low repetitions, high sets
4. low repetitions, low sets
How frequently were you training each muscle group? 1. 1 time/wk
2. 2 times/wk
3. 3 times/wk
4. >3 times/wk
Leading up to/during this period, were you experiencing any other nontraining stress? 1. Dieting (calorie restriction)
2. Private life stress
3. Work-related stress
4. Other nontraining stressors
5. None of the above
6. Viral infection
7. Mental health condition
5. Symptoms
Symptoms Open
Please rate the severity of the symptoms above Insignificant | Extreme
Did you also experience any of these symptoms before you noticed the decline in performance? Open
Did you experience any other symptoms during this period? Open
Please describe the other symptoms you experienced. Open
6. Recovery
Did you seek help/search for information when this occurred? 1. No
2. Yes—Doctor
3. Yes—Coach
4. Yes—Internet/Web sources
5. Yes—Other
What recovery/training strategies did you use in order to return performance to normal? 1. Decrease training intensity
2. Decrease training frequency
3. Decrease training volume
4. Increase calorie intake
5. Eliminate stressful contextual (nontraining)
factors
6. Supplementation
7. Medicine/seek medical help
8. Other
If “other,”please specify Open
Would you define this period as 1. Overtraining
2. Overreaching
3. Acute fatigue
4. Other
Abbreviation: RM, repetition maximum.
4(Ahead of Print)
The most reported symptoms for each duration of training
maladaptation are displayed in Figure 4. A complete list of the
symptoms and frequency of reporting can be found in
Supplementary Table S2 (available online). General feelings of
fatigue were the most common self-reported symptom overall
(n = 153, 35.7%) and in each time frame of training maladaptation
(<1 wk: n = 48, 28.9%; 1 wk–1 mo: n = 74, 27.0%; 1–3mo:n=25,
25.5%; and >4 mo: n = 6, 22.2%). Musculoskeletal aches and pain
Figure 1 —Sample selection.
Table 2 Frequency of Self-Reported Unexplained Decrease in Performance
Category Sport/discipline Total
Decrease
in performance, %
No decrease
in performance, %
RE only Powerlifting 231 69.3 30.7
Bodybuilding 138 76.0 24.0
Weightlifting 71 76.0 24.0
Strongman 23 47.8 52.2
Total 463 71.3 28.7
RE combined Rugby 54 63.0 37.0
CrossFit 42 81.0 19.0
Sprint 21 66.7 33.3
American football 10 60.0 40.0
Hurdles 4 50.0 50.0
Javelin 3 66.7 33.3
Long jump 3 100.0 0.0
Shot put 2 100.0 0.0
Discus 1 0.0 100.0
Pole vault 1 100.0 0.0
Triple jump 1 100.0 0.0
Total 142 69.7 33.3
Combined total 605 70.9 29.1
Abbreviation: RE, resistance exercise.
(Ahead of Print)
Symptoms of Overtraining in Resistance Exercise 5
were the second most frequent self-reported symptom for acute
maladaptation to training (FOR: n = 15, 9.0%; NFOR: n = 25, 9.1%).
Discussion
Finding the optimal balance between training and recovery in order
to enhance athletic performance and simultaneously avoid maladap-
tive training conditions continues to challenge both coaches and
athletes. Despite the potentially serious implications of overtraining
on athletic performance, to date, a decrease in sport-specific perfor-
mance, which cannot be explained by underlying conditions, is the
only diagnostic marker.
13
The purpose of this study was to provide
details on the nature and symptomatic profile of training maladapta-
tion in competitive resistance-based athletes to examine whether
there are symptoms that may be used as prognostic indicators of
overtraining. A greater understanding of the symptomatic profile of
maladaptation in resistance-based athletes may allow for the devel-
opment of valid, reliable, and objective prognostic and diagnostic
tools that do not involve maximal performance tests. This is the first
global survey of experiences and self-reported symptoms of
Table 3 Descriptive Characteristics of 605 Respondents
Characteristic RE only, n (SD) RE combined, n (SD) Total, N (SD)
Male 340 112 452
Female 123 30 153
Age, y 29.70 (9.05) 28.00 (9.04) 29.27 (9.07)
Weight, kg 82.37 (18.11) 84.06 (20.10) 83.53 (18.59)
Height, cm 173.95 (8.79) 178.25 (12.45) 174.96 (9.93)
Training, y 4.45 (2.89) 6.54 (3.14) 4.94 (3.08)
Squat 1RM, kg
Male 178.62 (45.05), Range: 50–300 161.73 (44.29), Range: 30–290 174.37 (45.40), Range: 30–300
Female 116.48 (33.25), Range: 55–215 99.89 (27.35), Range: 60–174 113.54 (32.77), Range: 55–215
Bench-press 1RM, kg
Male 125.69 (30.97), Range: 50–265 115.93 (28.64), Range: 20–200 123.28 (30.67), Range: 20–265
Female 69.97 (20.85), Range: 28–155 52.15 (13.41), Range: 25–85 66.85 (20.86), Range: 25–155
Competition level
Club 166 33 149
Regional 90 22 112
State 54 12 66
National 141 50 191
International 62 25 87
Abbreviations: 1RM, 1-repetition maximum; RE, resistance exercise.
Figure 2 —Flow chart of maladaptation to training responses.
Figure 3 —Difference between the proportions of participants training
to muscle failure and participants training without muscle failure by the
severity of training maladaptation. CI indicates confidence interval.
(Ahead of Print)
6Grandou et al
unexplained underperformance in a large sample of competitive
resistance-based athletes across 50 countries.
Previous studies have suggested that training maladaptation is
asignificant problem in resistance-based sports.
11
The purpose of the
present study did not include the determination of the prevalence or
incidence of overtraining conditions in resistance exercise. How-
ever, a significant number of respondents indicated that they had
previously experienced an unexplained decline in performance
Table 4 Dichotomous Frequency of Additional Stressors in Respondents Experiencing Training Maladaptation
“Yes”responses, n (%)
Additional stressor <1 wk 1 wk to 1 mo 1–3mo >4 mo Total
Work 53 (48.1) 86 (48.5) 29 (54.7) 9 (45.0) 177 (25.5)
Life 48 (43.6) 76 (42.9) 28 (52.8) 9 (45.0) 161 (23.2)
Dieting 49 (44.5) 78 (44.0) 23 (43.4) 9 (45.0) 159 (22.9)
Other 21 (19.0) 36 (20.3) 9 (16.9) 4 (20.0) 70 (10.1)
Mental health 20 (18.1) 22 (12.4) 15 (28.3) 4 (20.0) 61 (8.8)
Virus 5 (4.5) 4 (2.2) 4 (7.5) 2 (10.0) 15 (2.2)
None 20 (18.1) 23 (12.9) 5 (9.4) 4 (20.0) 52 (7.5)
Figure 4 —Most frequent self-reported symptoms of training maladaptation.
(Ahead of Print)
Symptoms of Overtraining in Resistance Exercise 7
(70.9%). The majority of athletes reported a performance impairment
that lasted between 1 wk and 1 mo (43.8%). A decline in performance
of this duration may be reflective of FOR or NFOR, in accordance
with the well-accepted presentation of stages of overtraining.
5
Based
on this classification, in our sample, the proportion of respondents
reporting a decline in performance of more than 4 mo (ie, potentially
indicative of severe OTS) was relatively low (4.7%). The low
proportion of long-term underperformance, compared with the over-
all prevalence of training maladaptation, is consistent with the
previous literature, which suggests that cases of the OTS are less
common.
4
However, the differential diagnosis of FOR, NFOR, or
OTS based on the survey responses is beyond the scope of this paper.
Due to the continuous nature of overtraining, defining the cutoff point
betweenFOR,NFOR,andOTSbasedontheproposeddefinitions of
Meeusen et al
5
is difficult. Examination of the appropriateness of
using similar diagnostic criteria (time frame of performance decline)
for both endurance- and resistance-based sports should be considered.
The detrimental effects of overtraining on athletic performance
have led to the search for prognostic symptoms that can be used to
prevent imminent overtraining. However, self-reported symptom
prevalence has not been studied in competitive athletes involved in
resistance-based sports. Determination of the most frequent self-
reported symptoms of training maladaptation is of key practical
significance for athletes and coaches in resistance-based sports, as
it may provide a simple tool that does not require physical tests
or a biochemical analysis to assess both training and competition
performance. Subjective feelings of general fatigue were the most
common self-reported symptom in this study, regardless of the
duration of training maladaptation. Athletes and coaches should
attempt to monitor for subjective feelings of fatigue during periods of
high training load to monitor for possible maladaptation. However,
the symptom of fatigue is poorly defined, and therefore, careful
inquiry is needed to distinguish lack of energy from exhaustion or
sleepiness.
15
Furthermore, it is unclear whether the general symptom
of fatigue is a physiological response, psychological perception, or
symptom of physical or psychiatric disorders.
16
The multidimen-
sional nature of fatigue introduces difficulties in quantifying the
subjective feeling. Future studies should test or develop appropriate
instruments to differentiate acute from chronic fatigue.
It is difficult to separate the symptoms of overtraining from
those of normal fatigue that may result from high intensity and/or
volume training sessions that are necessary to promote physiologi-
cal adaptations. Although the decline in performance associated
with overtraining appears to be accompanied by symptoms of
generalized fatigue, the presence of fatigue is not necessarily
synonymous with forthcoming training maladaptation. A multidi-
mensional approach to the assessment and monitoring of training
maladaptation is likely required. Athletes and coaches should
regularly monitor a combination of performance and symptomatic
variables to identify athletes that may be approaching FOR, NFOR,
or OTS. However, the diagnostic criteria of maladaptive conditions
remain a decline in maximal performance lasting “days–weeks”
for FOR, “weeks–months”for NFOR and “months . . .”for OTS.
5
Accordingly, an accurate diagnosis can only be made retrospec-
tively, once confounding factors that may be attributed to the
decline in performance have been excluded.
5
Apart from fatigue, a variety of secondary psychological and
physiological symptoms were reported by athletes, the expression
of which varies depending on the individual, training methods, and
other contextual factors. Musculoskeletal aches and pains were a
frequent complaint of the respondents who reported acute durations
of training maladaptation (<1wkand1wk–1 mo). Although the
etiology of musculoskeletal aches and pain is multifactorial, there
is a general consensus that repeated loading of high forces may
create the potential for acute joint or musculotendinous injury.
17
These results may suggest that an imbalance between training and
recovery may result in acute musculoskeletal pain responses, such
as swelling or micro trauma to tissues. However, these responses
are likely to be transient, as musculoskeletal aches and pains were
not among the most reported symptoms in chronic maladaptive
conditions (1–3 and >4 mo). These findings are supported by
Cadegiani and Kater,
18
who reported that impaired muscle recov-
ery may be a characteristic of the OTS. During periods of high-
intensity resistance training, athletes and coaches should monitor
subjective symptoms of musculoskeletal aches and pain, as chronic
maladaptation to training may be avoided if enough recovery is
implemented.
Given the heterogeneity and variability of the symptoms of
overtraining in resistance exercise and the present state of research, a
single symptom that can be used to predict ensuing overtraining is
unlikely. The interindividual variability of the symptoms of over-
training, as well as the variable nature of the stressors that may cause
overtraining, suggest the need for a variety of parameters as markers
of training maladaptation. The results of this survey suggest that, at
present, no particular symptomatic profile can be used to distinguish
between maladaptive conditions (FOR, NFOR, and OTS) in resis-
tance-based athletes. This may be due to the variability of symptoms
or the proposed continuum theory of training maladaptation. If
overtraining exists on a continuum, it may be difficult to differentiate
between the symptoms of acute fatigue, overreaching, and over-
training. Kuipers and Keizer
19
suggest that the symptoms of over-
training in endurance activities appear progressively as fatigue
accumulates. Future studies should seek to evaluate the severity
and progression of symptoms in resistance-based athletes at different
stages of overreaching and overtraining.
The pathogenesis of maladaptation in resistance-based sports
is not completely understood. However, it is well established that
causes of training maladaptation are multifactorial.
5,9
In agree-
ment with previous research in endurance activities,
20,21
the
present findings suggest that a combination of training and non-
training stressors are present at the time of resistance-training
maladaptation. The vast majority (92.5%) of athletes experiencing
an unexplained decline in performance also reported experiencing
additional stress outside of training. Similarly, Cadegiani and
Kater
9
identified a relationship between susceptibility to maladap-
tation and nontraining stressors. These findings suggest that train-
ing maladaptation is not only the result of excessive physical
training. Coaches and athletes should be aware of potential stres-
sors outside of training, including caloric and macronutrient intake,
as well as concurrent cognitive demands. Additional social and
environmental stressors must be considered and managed appro-
priately to prevent training maladaptation. Therefore, regular
psychological assessment of athletes who complete intensive
resistance training may provide benefits by detecting early symp-
toms of maladaptive training.
A large proportion of athletes with a decrease in performance
lasting greater than 4 mo reported training to muscular failure
(65%). This finding suggests that severe maladaptation is associ-
ated with high-intensity resistance training to muscular failure.
Previous studies have suggested that high-intensity training may
increase susceptibility to overtraining in resistance exercise.
13,22
However, at present, no previous study has examined how training
to muscular failure may impact the etiology of overtraining in
resistance exercise. It is well accepted that there is interindividual
(Ahead of Print)
8Grandou et al
variability in the way that athletes tolerate increases in training
load, training intensity, and competition and nontraining stress.
6
Therefore, training load and intensity must be individualized,
depending on each athlete’s response.
Limitations
This is the first global survey of maladaptation to training in
resistance-based sports. However, there are limitations to this study
that must be acknowledged. The main limitation of this study was the
self-reported quantification of performance decrements. Possible
interparticipant variability in the determination of an unexplained
decrease in performance and recency bias should be considered
when interpreting the findings of this study. For example, low energy
availability resulting in relative energy deficiency in sport may have
contributed to a decline in performance that the participants unknow-
ingly interpreted as “unexplained underperformance.”Future studies
are required to understand eating patterns as additional stressors in
relation to overtraining in resistance exercise. The study participants
were drawn from a convenience sample and restricted tocompetitive
resistance-based athletes; therefore, the findings cannot be general-
ized to noncompetitive athletes or endurance athletes. In addition,
this study adopted a cross-sectional design precluding any causal
inferences (causal link with symptoms). Furthermore, no precau-
tionary measures were used to prevent multiple entries from the same
individual. Caution should be used when comparing athletes under-
taking resistance exercise only or combined training; it is unknown
whether only resistance exercise participants were engaging in
additional aerobic exercise at the time of maladaptation. The diffi-
culties and ethical considerations of studying overtraining in athletic
populations are appreciated; however, well-designed studies are
required to gain a greater understanding of maladaptive training
conditions in resistance-based athletes.
Practical Applications
The purpose of this study was to provide details on the nature and
symptomatic profile of training maladaptation in competitive
resistance-based athletes to examine whether there are symptoms
that may be used as prognostic indicators of overtraining. Consid-
ering that overtraining is likely associated with the duration and
severity of symptoms rather than a singular symptom, practitioners
should routinely and systematically assess fatigue, musculoskeletal
pain, and nontraining stressors during periods of high training load
and/or intensity. The development of valid and reliable question-
naires or other diagnostic measures in athletic populations are
required for assessing fatigue and additional symptoms related to
training maladaptation. The persistence of such symptoms may be
indicative of a negative progression in training. Given the multi-
factorial nature of the etiology and symptoms of overtraining,
future studies are required to gain a greater understanding of the
underlying mechanisms of training maladaptation. Well-designed
studies with demonstrated decreases in performance and follow-up
measures are required for the development of causal assumptions
of overtraining for use in future prognostic studies.
Conclusion
Overtraining conditions are characterized by an imbalance between
training and nontraining stress and recovery. Maladaptive conditions
may present with a wide range of clinically significant symptoms,
such as fatigue, musculoskeletal aches and pain, loss of motivation,
insomnia, and/or other physical or psychological symptoms. Sub-
jective feelings of fatigue are likely to accompany training malad-
aptation in resistance exercise. However, the results from this
exploratory study do not permit causal conclusions. It is evident
that the accompanying symptoms of training maladaptation may be
variable in nature. The multidimensional nature of fatigue and
individual variability in symptomatic responses precludes the defin-
itive prognosis or differential diagnosis of FOR, NFOR, or OTS in
resistance exercise. At present, the correct diagnosis of overreaching
and overtraining in resistance exercise remains a demonstrated
decrease in maximal performance capacity.
Acknowledgments
The authors wish to thank Brad Schoenfeld, Mike Israetel, Stuart McMillan,
Carlo Buzzichelli, Greg Nuckols, Johann Bilsborough, David Nolan, Layne
Norton, Bill Campbell, Michael Pang, Jackson Peos, Jared Feather, Luke
Tulloch, Kristen Dunsmore, Patrick Umphrey, Brandon Roberts, and all
others who aided in the distribution of this survey. The raw and coded data
that support the findings of this study are available at https://osf.io/je2rf and
https://osf.io/bgxpa, respectively.
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