Training Load and Fatigue Marker Associations with Injury and Illness: A Systematic Review of Longitudinal Studies.
BACKGROUND
Coaches, sport scientists, clinicians and medical personnel face a constant challenge to prescribe sufficient training load to produce training adaption while minimising fatigue, performance inhibition and risk of injury/illness.


OBJECTIVE
The aim of this review was to investigate the relationship between injury and illness and longitudinal training load and fatigue markers in sporting populations.


METHODS
Systematic searches of the Web of Science and PubMed online databases to August 2015 were conducted for articles reporting relationships between training load/fatigue measures and injury/illness in athlete populations.


RESULTS
From the initial 5943 articles identified, 2863 duplicates were removed, followed by a further 2833 articles from title and abstract selection. Manual searching of the reference lists of the remaining 247 articles, together with use of the Google Scholar 'cited by' tool, yielded 205 extra articles deemed worthy of assessment. Sixty-eight studies were subsequently selected for inclusion in this study, of which 45 investigated injury only, 17 investigated illness only, and 6 investigated both injury and illness. This systematic review highlighted a number of key findings, including disparity within the literature regarding the use of various terminologies such as training load, fatigue, injury and illness. Athletes are at an increased risk of injury/illness at key stages in their training and competition, including periods of training load intensification and periods of accumulated training loads.


CONCLUSIONS
Further investigation of individual athlete characteristics is required due to their impact on internal training load and, therefore, susceptibility to injury/illness.
Research Centre in Applied Sports, Technology, Exercise and Medicine, College of Engineering, Swansea University, Fabian Way, Swansea, SA1 8QQ, Wales, UK. chrisjones32@hotmail.co.uk.
Christopher M
CM
Jones
Research Centre in Applied Sports, Technology, Exercise and Medicine, College of Engineering, Swansea University, Fabian Way, Swansea, SA1 8QQ, Wales, UK.
Peter C
PC
Griffiths
Cardiff School of Sport, Cardiff Metropolitan University, Cardiff, Wales, UK.
Stephen D
SD
Mellalieu
D056352:Athletes; D001265:Athletic Injuries / Q000517:prevention & control*; D015415:Biomarkers / Q000032:analysis*; D006801:Humans; D018763:Muscle Fatigue / Q000502:physiology*; D064797:Physical Conditioning, Human / Q000379:methods*; D010806:Physical Education and Training / Q000379:methods*; D013177:Sports / Q000502:physiology*; D013647:Task Performance and Analysis; D016474:Weight-Bearing; D016526:Workload
D015415:Biomarkers
Sports Med. 2014 May;44 Suppl 1:S13-23
24791913
J Sci Med Sport. 2011 May;14(3):210-5
21324742
Med Sci Sports Exerc. 1996 Mar;28(3):285-90
8776216
J Pers Soc Psychol. 1988 Mar;54(3):486-95
3361420
J Strength Cond Res. 2011 Jun;25(6):1553-62
21602645
Open Access J Sports Med. 2010 Jun 17;1:77-85
24198545
Am J Sports Med. 2011 Jun;39(6):1226-32
21335353
J Sports Sci Med. 2010 Dec 01;9(4):652-63
24149793
Sports Med. 2013 Oct;43(10):1043-55
23839770
Br J Sports Med. 2004 Aug;38(4):493-7
15273193
Phys Ther. 2003 Aug;83(8):713-21
12882612
Am J Sports Med. 1996 Mar-Apr;24(2):137-43
8775109
Scand J Med Sci Sports. 2012 Jun;22(3):410-7
21385218
Am J Sports Med. 2004 Jan-Feb;32(1 Suppl):5S-16S
14754854
Eur J Appl Physiol. 2010 Jan;108(1):113-22
19756700
Int J Sports Physiol Perform. 2012 Sep;7(3):210-7
22172687
Am J Sports Med. 2000;28(5 Suppl):S69-74
11032110
J Sci Med Sport. 2003 Sep;6(3):359-67
14609154
Br J Sports Med. 2003;37(5):416-9
14514532
J Sci Med Sport. 2013 Nov;16(6):499-503
23333045
J Strength Cond Res. 2010 Oct;24(10):2593-603
20847703
Int J Sports Physiol Perform. 2015 May;10(4):524-7
25310521
Res Q Exerc Sport. 2015;86(4):379-86
26288253
J Strength Cond Res. 2014 Feb;28(2):467-73
24473469
Scand J Med Sci Sports. 2015 Dec;25(6):854-9
25892560
Eur J Appl Physiol. 2010 Oct;110(3):627-34
20574678
Med Sci Sports Exerc. 2013 Jan;45(1):186-205
23247672
Br J Sports Med. 2007 May;41(5):328-31
17452684
Br J Sports Med. 2006 Mar;40(3):260-3
16505085
J Strength Cond Res. 2010 Nov;24(11):2908-19
20703171
Br J Sports Med. 2011 Aug;45(10):805-8
19622529
Eur J Sport Sci. 2015;15(7):573-82
25216043
J Sci Med Sport. 2016 Feb;19(2):113-6
25770421
Br J Sports Med. 2014 Apr;48(8):708-12
23962877
Biol Sport. 2013 Dec;30(4):289-94
24744500
Br J Sports Med. 2017 Mar;51(6):486-487
26941279
J Sports Sci Med. 2010 Jun 01;9(2):347-52
24149706
Int J Sports Med. 2000 May;21(4):302-7
10853703
J Sci Med Sport. 2014 Jul;17(4):366-70
24262336
Br J Sports Med. 2013 Aug;47(12):743-7
23851296
J Sci Med Sport. 2015 Jan;18(1):26-30
25245426
J Sports Med Phys Fitness. 2012 Dec;52(6):631-8
23187326
Scand J Med Sci Sports. 2005 Feb;15(1):21-8
15679568
Br J Sports Med. 2015 Mar;49(6):390-4
23422422
J Strength Cond Res. 2015 Jun;29(6):1705-12
26010801
Arthroscopy. 2004 Apr;20(4):414-8
15067282
Br J Sports Med. 2005 Jun;39(6):324-9
15911600
Br J Sports Med. 2004 Dec;38(6):743-9
15562171
Sports Med. 2015 Oct;45(10):1387-400
26206724
Med Sci Sports Exerc. 1996 Sep;28(9):1171-9
8883006
J Strength Cond Res. 2014 Jan;28(1):194-200
23539085
J Sci Med Sport. 2016 Jan;19(1):24-8
25669126
J Sci Med Sport. 2012 Nov;15(6):496-504
22748762
J Strength Cond Res. 2003 Nov;17(4):734-8
14636112
Lancet. 1988 Dec 3;2(8623):1267-73
2904004
J Sci Med Sport. 2015 May;18(3):328-32
24785367
J Strength Cond Res. 2005 May;19(2):400-8
15903382
J Strength Cond Res. 2012 May;26(5):1431-40
22516913
Clin J Sport Med. 2007 May;17 (3):192-6
17513910
Sports Med. 2014 Jul;44(7):989-1003
24715614
Br J Sports Med. 2016 Sep;50(17 ):1017-8
27251895
J Strength Cond Res. 2010 Aug;24(8):2079-84
20613646
J Sports Sci. 2007 Nov;25(13):1507-19
17852696
Br J Sports Med. 2016 Mar;50(5):281-91
26423706
Sports Med. 2014 Aug;44(8):1113-24
24807838
J Strength Cond Res. 2011 Apr;25(4):1030-9
20703169
Br J Sports Med. 2016 Apr;50(8):471-5
26701923
Br J Sports Med. 2016 Apr;50(8):444-5
26795610
Med Sci Sports Exerc. 2008 Jul;40(7):1228-36
18580401
Pediatr Exerc Sci. 2014 May;26(2):195-202
24722819
Br J Sports Med. 2005 Oct;39(10 ):757-66
16183774
J Strength Cond Res. 2014 Aug;28(8):2244-52
25054573
J Athl Train. 2014 Nov-Dec;49(6):786-93
25365132
J Sci Med Sport. 2015 May;18(3):278-82
24908360
J Sports Sci. 2004 May;22(5):409-17
15160594
Am J Sports Med. 2008 Jan;36(1):33-9
17940147
J Strength Cond Res. 2013 Jun;27(6):1471-8
22990565
J Strength Cond Res. 2012 Dec;26(12):3189-96
22996020
Am J Sports Med. 2005 Mar;33(3):428-34
15716260
Sports Med. 2014 Apr;44(4):423-8
24469737
J Sports Sci. 2015;33(20):2140-8
26168148
Med Sci Sports Exerc. 2011 Mar;43(3):388-97
20631639
Med Sci Sports Exerc. 1998 Jul;30(7):1164-8
9662690
J Strength Cond Res. 2014 Dec;28(12):3476-83
24983851
Sports Med. 2015 Aug;45(8):1175-90
25946993
J Sci Med Sport. 2013 Sep;16(5):460-5
23245879
Scand J Med Sci Sports. 2003 Dec;13(6):364-70
14617057
J Sports Sci Med. 2015 May 08;14(2):394-401
25983590
J Clin Epidemiol. 2005 Jun;58(6):609-17
15878475
Knee Surg Sports Traumatol Arthrosc. 2009 Jul;17 (7):705-29
19452139
Immunol Cell Biol. 1999 Aug;77(4):351-5
10457203
J Sports Sci. 2015;33(5):467-75
25113820
J Sports Sci. 2008 Jun;26(8):863-73
18569552
Int J Sports Med. 2015 Aug;36(9):722-8
25831403
Sports Med. 2006;36(11):977-99
17052133
Med Sci Sports Exerc. 2014;46(5):1036-45
24091995
Clin J Sport Med. 2005 Jul;15(4):246-52
16003039
Br J Sports Med. 2016 Mar;50(5):273-80
26758673
Med Sci Sports Exerc. 2005 Mar;37(3):374-80
15741834
Br J Sports Med. 2016 Feb;50(4):231-6
26511006
J Orthop Sports Phys Ther. 2003 Jan;33(1):4-20
12570282
Br J Sports Med. 2014 Sep;48(17):1276-80
23501833
Physiol Rev. 2008 Jan;88(1):287-332
18195089
J Sports Sci. 2005 Jun;23(6):583-92
16195007
J Sci Med Sport. 2016 Oct;19(10 ):778-83
26839047
Br J Sports Med. 2016 May 10;:null
27166288
Sports Med. 2016 Jun;46(6):861-83
26822969
Am J Sports Med. 2011 Sep;39(9):1984-8
21737835
J Sci Med Sport. 2010 Nov;13(6):578-83
20483661
Sports Med. 2014 Nov;44 Suppl 2:S139-47
25200666
Scand J Med Sci Sports. 2012 Apr;22(2):285-92
21039901
Front Physiol. 2012 Apr 11;3:82
22514538
J Sports Med Phys Fitness. 2010 Dec;50(4):475-85
21178935
Int J Sports Med. 2012 Jan;33(1):36-42
22012641
J Strength Cond Res. 2012 May;26(5):1396-401
22516911
Sports Med. 2016 Oct;46(10 ):1503-16
27071991
J Sci Med Sport. 2011 May;14(3):204-9
21256078
J Strength Cond Res. 2013 Apr;27(4):944-53
22692108
J Sports Sci Med. 2004 Dec 01;3(4):234-43
24624008
Br J Sports Med. 2016 Aug;50(16):1008-12
26851288
J Sci Med Sport. 2015 Nov;18(6):643-50
25620458
Br J Sports Med. 2015 Aug;49(16):1064-8
25755276
Am J Sports Med. 2009 Jun;37(6):1186-92
19346405
J Strength Cond Res. 2012 Apr;26(4):953-60
22323001
Biol Psychiatry. 2011 Jun 15;69(12):e113-25
21531388
Br J Sports Med. 2002 Feb;36(1):39-44
11867491
Br J Sports Med. 2010 Sep;44(11):809-15
20511621
Am J Clin Nutr. 1982 Nov;36(5):936-42
7137077
Int J Sports Physiol Perform. 2016 Apr;11(3):350-5
26309331
Spine (Phila Pa 1976). 2003 Jun 15;28(12):1290-9
12811274
J Strength Cond Res. 2009 Jul;23(4):1195-203
19528840
J Sport Rehabil. 2013 Feb;22(1):19-26
23404909
J Sports Sci. 2005 Jun;23(6):619-27
16195010
J Strength Cond Res. 2013 May;27(5):1253-9
22744297
J Strength Cond Res. 2014 Nov;28(11):3280-8
24845209