Journal of Strength and Conditioning Research Publish Ahead of Print DOI: 10.1519/JSC.0000000000000380
HIGH
INTENSITY
TRAINING
AND
SALIVARY
IMMUNOGLOBULIN-A
RESPONSES IN PROFESSIONAL TOP-LEVEL SOCCER PLAYERS: EFFECT OF TRAINING INTENSITY Adam L. OWEN
1,2
, Del P. WONG 3, Gordon DUNLOP 1, Carole GROUSSARD 4, Wiem
KEBSI 4, Alexandre DELLAL 5, Ryland MORGANS 6,7 Hassane ZOUHAL 4
Sheffield United Football Club, UK.
2
Université Claude Bernard Lyon 1, EA 642 Centre de Recherche et d’Innovation sur le
D
1
TE
Sport, Université de Lyon, Villeurbanne, France. 3
Human Performance Laboratory, Technological and Higher Education Institute of Hong
Kong (THEi), Hong Kong. 4
Movement, Sport and Health Sciences Laboratory (M2S), Rennes 2 University - ENS
Cachan, France.
Medical Centre Excellence FIFA, Santy Orthopedicae clinical, Lyon, France. Centre de
EP
5
recherche et d'innovation sur le Sport, Université de Lyon, France Liverpool Football Club, Sport Science Department, Liverpool, England, UK.
7
University of Glamorgan, Glamorgan, Wales, UK.
C C
6
Corresponding author: Prof. H. ZOUHAL Movement, Sport and health Sciences Laboratory (M2S), UFR-APS, Rennes 2 University, Avenue Charles Tillon, CS 24414, 35044 Rennes Cedex, France. Phone number: +33.2.99.14.17.75
A
Fax number: +33.2.99.14.17.74
E-mail: [email protected]
Running Head: Immune Response in Soccer Disclosure statement of funding: The research did not receive funding from the National Institutes of Health, Welcome Trust, Howard Hughes Medical Institute, or any other source requiring deposit).
Copyright Ó Lippincott Williams & Wilkins. All rights reserved.
Immune Response in Soccer
1
ABSTRACT This study aimed 1)- to test the hypothesis that salivary immunoglobulin A (s-IgA) would vary with training intensity sessions (low intensity [LI] vs. high intensity sessions [HI]) during a traditional training program divided in 4 training periods and 2)- to identify key
D
variables (e.g. GPS data, RPE, training duration) which could affect s-IgA. Saliva samples of 10 elite professional soccer players were collected a)- before the
TE
investigation started to establish the baseline level, b)-before and after each 4 training sessions (LI vs. HI). Training intensity was monitored as internal (via heart rate responses and RPE) and external (via GPS) loads.
EP
HI sessions were associated with higher external load (GPS) and with higher RPE. Baseline and Pre-Training s-IgA did not differ between the 4 training sessions both for HI and LI. Post-Training s-IgA were not different (in absolute value and in percentage of change) between HI and LI sessions at the first three periods. However, at the fourth period, s-IgA
C C
concentration for HI session was significantly lower (p 21.6 km.h-1;
A
3) Frequency of efforts at high intensity (FEHS), expressed as the number times a player was able to achieve a speed > 21.6 km.h-1; 4) High intensity distance covered as a percentage of
the total distance covered within the training session; and 5) Meterage per minute, taken as an average of the total distance covered within the session divided by session duration. In addition to measuring HR response to quantify the individual training response, sessionRPE was also implemented within this investigation. The session-RPE assessment was
Copyright Ó Lippincott Williams & Wilkins. All rights reserved.
Immune Response in Soccer
9
conducted in accordance with the procedures previously described by Foster (6). Briefly, this method of monitoring training and competition load required each athlete to provide a session-RPE value using Borg’s 6-20 scale to represent the perceived exertion of the whole training session. To ensure that the perceived exertion was reflective of the entire session rather than the last effort, data was collected in the proceeding morning following each
D
training session. In conjunction with detailing session-RPE, players were required to answer and provide
TE
scores (1 = very poor, 5 = excellent) on list simple questions within a questionnaire, intended to establish a picture of individual daily wellness. The questions and aggregation of scores provided an insight into players’ perception of their current energy levels, quality of sleep, readiness to train, and lower body soreness in response to the previous days’ training session
investigation period.
EP
(14). The data were recorded by the same investigator on every occasion throughout the
Saliva Sampling and Analysis
C C
Player provided saliva samples 30 minutes before training session commencement and immediately post training. Additionally, prior to saliva sampling, to regulate saliva secretion players were required to ensure adequate hydration (consumed 500ml of water) as
A
dehydration has been associated with reduced resting saliva flow rates (42). A total of 90 saliva samples were collected and analysed from this cohort of players, using the IPRO OFC collection kits in combination with a real time lateral flow device (LFD) respectively. This method has been validated previously for oral fluid collection in the immunoassay of immunoglobulins in sports persons (5) and correlates well with other methods (ELISA) adopted in the determination of s-IgA (31).
Copyright Ó Lippincott Williams & Wilkins. All rights reserved.
Immune Response in Soccer
10
In accordance to the manufacture’s guidelines, after thoroughly rinsing their mouths with water, unstimulated saliva samples were collected as follow. Players were required to place a synthetic polymer-based swab material attached to a volume adequacy indicator stem in their mouth. Once the OFC kits collect 0.5ml of oral fluid (collection times typically in the range of 20 - 50 seconds) the volume adequacy indictor changed colour and indicated to the player to place the swab in the dropper bottle containing a known volume of extraction buffer. The bottle was then shaken vigorously for a period of 60 seconds and the collected sample was
D
ready to be analysed via a real time lateral flow device (IPRO Interactive). For the LFD, two
drops of saliva/buffer mix were added to the sample window of the LFD cassette. The liquid
TE
in turn then ran length of the test strip via capillary action creating a control and test line
visible in the test window. Five minutes after the sample was added the test line intensity was measured in an IPRO reader. The test line intensity was inversely proportional to the s-IgA
Statistical analyses
EP
concentration in the sample analysed.
Data were expressed as mean values ± standard deviation (SD). After testing for normal
C C
distribution (Kolmogorov–Smirnov test), differences within and between the training periods (low and intense period) were analysed using a two-way analysis of variance for repeated measurements: factor one was the time of test (Pre vs. Post) and factor two was the intensity of training session (low vs. high). Pearson correlation coefficient evaluated the
A
correlation between the indicators of external or internal load ands-IgA values. The magnitude of the correlations was determined using the modified scale by Hopkins (2009): r < 0.1, trivial; 0.1–0.3, small; > 0.3–0.5, moderate; > 0.5–0.7, large; > 0.7–0.9, very large; > 0.9, nearly perfect; and 1 perfect (21). The reliability was assessed by intra-class correlations (ICCs). The difference was considered statistically significant when P0.8 (
HIGH
INTENSITY
TRAINING
AND
SALIVARY
IMMUNOGLOBULIN-A
RESPONSES IN PROFESSIONAL TOP-LEVEL SOCCER PLAYERS: EFFECT OF TRAINING INTENSITY Adam L. OWEN
1,2
, Del P. WONG 3, Gordon DUNLOP 1, Carole GROUSSARD 4, Wiem
KEBSI 4, Alexandre DELLAL 5, Ryland MORGANS 6,7 Hassane ZOUHAL 4
Sheffield United Football Club, UK.
2
Université Claude Bernard Lyon 1, EA 642 Centre de Recherche et d’Innovation sur le
D
1
TE
Sport, Université de Lyon, Villeurbanne, France. 3
Human Performance Laboratory, Technological and Higher Education Institute of Hong
Kong (THEi), Hong Kong. 4
Movement, Sport and Health Sciences Laboratory (M2S), Rennes 2 University - ENS
Cachan, France.
Medical Centre Excellence FIFA, Santy Orthopedicae clinical, Lyon, France. Centre de
EP
5
recherche et d'innovation sur le Sport, Université de Lyon, France Liverpool Football Club, Sport Science Department, Liverpool, England, UK.
7
University of Glamorgan, Glamorgan, Wales, UK.
C C
6
Corresponding author: Prof. H. ZOUHAL Movement, Sport and health Sciences Laboratory (M2S), UFR-APS, Rennes 2 University, Avenue Charles Tillon, CS 24414, 35044 Rennes Cedex, France. Phone number: +33.2.99.14.17.75
A
Fax number: +33.2.99.14.17.74
E-mail: [email protected]
Running Head: Immune Response in Soccer Disclosure statement of funding: The research did not receive funding from the National Institutes of Health, Welcome Trust, Howard Hughes Medical Institute, or any other source requiring deposit).
Copyright Ó Lippincott Williams & Wilkins. All rights reserved.
Immune Response in Soccer
1
ABSTRACT This study aimed 1)- to test the hypothesis that salivary immunoglobulin A (s-IgA) would vary with training intensity sessions (low intensity [LI] vs. high intensity sessions [HI]) during a traditional training program divided in 4 training periods and 2)- to identify key
D
variables (e.g. GPS data, RPE, training duration) which could affect s-IgA. Saliva samples of 10 elite professional soccer players were collected a)- before the
TE
investigation started to establish the baseline level, b)-before and after each 4 training sessions (LI vs. HI). Training intensity was monitored as internal (via heart rate responses and RPE) and external (via GPS) loads.
EP
HI sessions were associated with higher external load (GPS) and with higher RPE. Baseline and Pre-Training s-IgA did not differ between the 4 training sessions both for HI and LI. Post-Training s-IgA were not different (in absolute value and in percentage of change) between HI and LI sessions at the first three periods. However, at the fourth period, s-IgA
C C
concentration for HI session was significantly lower (p 21.6 km.h-1;
A
3) Frequency of efforts at high intensity (FEHS), expressed as the number times a player was able to achieve a speed > 21.6 km.h-1; 4) High intensity distance covered as a percentage of
the total distance covered within the training session; and 5) Meterage per minute, taken as an average of the total distance covered within the session divided by session duration. In addition to measuring HR response to quantify the individual training response, sessionRPE was also implemented within this investigation. The session-RPE assessment was
Copyright Ó Lippincott Williams & Wilkins. All rights reserved.
Immune Response in Soccer
9
conducted in accordance with the procedures previously described by Foster (6). Briefly, this method of monitoring training and competition load required each athlete to provide a session-RPE value using Borg’s 6-20 scale to represent the perceived exertion of the whole training session. To ensure that the perceived exertion was reflective of the entire session rather than the last effort, data was collected in the proceeding morning following each
D
training session. In conjunction with detailing session-RPE, players were required to answer and provide
TE
scores (1 = very poor, 5 = excellent) on list simple questions within a questionnaire, intended to establish a picture of individual daily wellness. The questions and aggregation of scores provided an insight into players’ perception of their current energy levels, quality of sleep, readiness to train, and lower body soreness in response to the previous days’ training session
investigation period.
EP
(14). The data were recorded by the same investigator on every occasion throughout the
Saliva Sampling and Analysis
C C
Player provided saliva samples 30 minutes before training session commencement and immediately post training. Additionally, prior to saliva sampling, to regulate saliva secretion players were required to ensure adequate hydration (consumed 500ml of water) as
A
dehydration has been associated with reduced resting saliva flow rates (42). A total of 90 saliva samples were collected and analysed from this cohort of players, using the IPRO OFC collection kits in combination with a real time lateral flow device (LFD) respectively. This method has been validated previously for oral fluid collection in the immunoassay of immunoglobulins in sports persons (5) and correlates well with other methods (ELISA) adopted in the determination of s-IgA (31).
Copyright Ó Lippincott Williams & Wilkins. All rights reserved.
Immune Response in Soccer
10
In accordance to the manufacture’s guidelines, after thoroughly rinsing their mouths with water, unstimulated saliva samples were collected as follow. Players were required to place a synthetic polymer-based swab material attached to a volume adequacy indicator stem in their mouth. Once the OFC kits collect 0.5ml of oral fluid (collection times typically in the range of 20 - 50 seconds) the volume adequacy indictor changed colour and indicated to the player to place the swab in the dropper bottle containing a known volume of extraction buffer. The bottle was then shaken vigorously for a period of 60 seconds and the collected sample was
D
ready to be analysed via a real time lateral flow device (IPRO Interactive). For the LFD, two
drops of saliva/buffer mix were added to the sample window of the LFD cassette. The liquid
TE
in turn then ran length of the test strip via capillary action creating a control and test line
visible in the test window. Five minutes after the sample was added the test line intensity was measured in an IPRO reader. The test line intensity was inversely proportional to the s-IgA
Statistical analyses
EP
concentration in the sample analysed.
Data were expressed as mean values ± standard deviation (SD). After testing for normal
C C
distribution (Kolmogorov–Smirnov test), differences within and between the training periods (low and intense period) were analysed using a two-way analysis of variance for repeated measurements: factor one was the time of test (Pre vs. Post) and factor two was the intensity of training session (low vs. high). Pearson correlation coefficient evaluated the
A
correlation between the indicators of external or internal load ands-IgA values. The magnitude of the correlations was determined using the modified scale by Hopkins (2009): r < 0.1, trivial; 0.1–0.3, small; > 0.3–0.5, moderate; > 0.5–0.7, large; > 0.7–0.9, very large; > 0.9, nearly perfect; and 1 perfect (21). The reliability was assessed by intra-class correlations (ICCs). The difference was considered statistically significant when P0.8 (
