Predicting sickness during a 2-week soccer camp at 3600 m (ISA3600)

Abstract

ObjectivesTo examine the time course of changes in wellness and health status markers before and after episodes of sickness in young soccer players during a high-altitude training camp (La Paz, 3600 m).MethodsWellness and fatigue were assessed daily on awakening using specifically-designed questionnaires and resting measures of heart rate and heart rate variability. The rating of perceived exertion and heart rate responses to a submaximal run (9 km/h) were also collected during each training session. Players who missed the morning screening for at least two consecutive days were considered as sick.ResultsFour players met the inclusion criteria. With the exception of submaximal exercise heart rate, which showed an almost certain and large increase before the day of sickness (4%; 90% confidence interval 3 to 6), there was no clear change in any of the other psychometric or physiological variables. There was a very likely moderate increase (79%, 22 to 64) in self-reported training load the day before the heart rate increase in sick players (4 of the 4 players, 100%). In contrast, training load was likely and slightly decreased (−24%, −78 to −11) in players who also showed an increased heart rate but remained healthy.ConclusionsA >4% increased heart rate during submaximal exercise in response to a moderate increase in perceived training load the previous day may be an indicator of sickness the next day. All other variables, that is, resting heart rate, heart rate variability and psychometric questionnaires may be less powerful at predicting sickness.

Wellness, fatigue and physical performance acclimatisation to a 2-week soccer camp at 3600 m (ISA3600)

“…Also, to control for the possible effect of fitness status and/or initial freshness on performance responses, all analyses were adjusted for baseline values collated in each group on the day of testing. Data from the four players who became sick32 were partially removed from analysis (2–3 sick days +2 following days). Threshold values were >0.2 (small), >0.6 (moderate) and >1.2 (large) 33.…”

Heart Rate Monitoring in Team Sports—A Conceptual Framework for Contextualizing Heart Rate Measures for Training and Recovery Prescription

“…Since the repeated assessment of maximal physical performance is unsuitable in (team sport) athletes, submaximal, non-exhaustive tests have been more frequently adopted by researchers and practitioners during recent decades (Buchheit, 2014 ; Halson, 2014 ; Akenhead and Nassis, 2016 ; Capostagno et al, 2016 ; Thorpe et al, 2017 ). However, the protocols used vary greatly in modality (running Malone et al, 2017 vs. cycling Thorpe et al, 2015 ), load characteristics (continuous Buchheit et al, 2010 vs. intermittent Brink et al, 2013 , linear Buchheit et al, 2010 vs. shuttle runs Bradley et al, 2011 , constant Buchheit et al, 2010 vs. graded Bradley et al, 2011 ), test duration (5 min Buchheit et al, 2010 to 16 min Vesterinen et al, 2017 ), intensity (low-intensity Buchheit et al, 2013c vs. high-intensity Vesterinen et al, 2017 ) and workload prescription (standardized Bradley et al, 2011 vs. individualized Buchheit et al, 2010 , internal Vesterinen et al, 2017 vs. external Bradley et al, 2011 ).…”

“…Complete cardiac autonomic recovery requires up to 24 h following low-intensity, 24–48 h following threshold-intensity and at least 48 h following high-intensity endurance exercise (Stanley et al, 2013 ). Therefore, acute changes in training load can result in altered vagal-related HRV (Stanley et al, 2013 ; Malone et al, 2017 ; Michael et al, 2017 ), HRR (Borresen and Lambert, 2007 ; Daanen et al, 2012 ; Malone et al, 2017 ) and HRex (Buchheit et al, 2013a , c ; Malone et al, 2017 ). Furthermore, stable (Plews et al, 2012 ) or reduced (Flatt and Esco, 2016 ) day-to-day variations (expressed as a weekly CV) in resting HRV have been observed together with positive adaptation, but also a large reduction in CV was reported before non-functional overreaching (Plews et al, 2012 ).…”

Improving team-sport player’s physical performance with altitude training: from beliefs to scientific evidence

“…Specifically, of a series of seven companion papers attempting to quantify the acute and chronic effects of competing at La Paz, Bolivia (3600 m) on game and training running performance, acclimatisation, haematology and sleeping patterns of national-level junior players, five are published in this supplement. The two remaining papers can be found in a regular issue of BJSM 21 22…”