World class endurance athletes endure extremely high training loads (frequency, duration and intensity) to achieve a maximal adaptive effect. Incomplete recovery can, however, lead to stress-related side-effects indicated by autonomic imbalance. Heart rate variability (HRV) is an established, noninvasive tool to investigate autonomic balance. At present, there is a lack of information regarding autonomic recovery during hard training periods in elite female endurance athletes. The aim of this present study was to investigate the relation between HRV, training load, and self reported form and fatigue during 3-week of competitive training in world-class female biathlon skiers. METHODS: Seven female world class biathlon skiers (25.6 +- 3.2 yr, 172.3 +- 3.4 cm, 62.5 +- 7.3 kg, 63.8 +- 2.6 ml•min-1•kg-1), all members of the Norwegian biathlon team, including World Cup and World Championship medal winners, participated in the study. HRV, training load, and self reported form and fatigue were recorded on a daily basis during a 3-week competitive training period. HRV was recorded with a Polar Heart Rate Monitor (Polar RS800) each morning for 5 minutes in the supine position. Low intensity (LIT), moderate intensity (MIT), and high intensity (HIT) endurance training were quantified by HR recordings during each training session. Overall training load (TRIMP) was calculated by multiplying the accumulated duration spent in each intensity zone by 1, 2, and 3 for the LIT, MIT and HIT, respectively. Self reported fatigue was scored on a 1 to 6 point scale (1 = no fatigue; 6 = maximal fatigued), and self reported form from a 4 to -4 point scale (4 = extremely good form/light feeling; -4 = extreme bad form/heavy feeling), after every training session. RESULTS: Preliminary analysis revealed no general relation between HRV, TRIMP, and self-reported fatigue and form; however, the -inter-individual variation was substantial. For some athletes, self reports of fatigue and form showed a time lag (1-4 days) to indices autonomic recovery, e.g., indices of improved or reduced form was preceded by reduced or increased HRV. However, variation in form and fatigue was small and the overall impression was that most athletes obtained autonomic recovery even after two succeeding days with competition. DISCUSSION: In general, world-class female biathlon athletes` shows fast autonomic recovery during a hard training and competition period, despite extremely high training loads. An overnight rest seems to be sufficient to recover from two training sessions and 2-4 hrs daily training. However, the inter-individual variation is substantial and recordings of HRV may be a useful tool for some athletes to monitor autonomic recovery during periods with high training loads.
© Copyright 2009 14th annual Congress of the European College of Sport Science, Oslo/Norway, June 24-27, 2009, Book of Abstracts. Veröffentlicht von The Norwegian School of Sport Sciences. Alle Rechte vorbehalten. / Übersetzt mit https://www.DeepL.com/Translator