Who, what & why?

In previous posts (such as this one) we have looked at the relationship between HRV and competitive performance. In general, top performers have the highest HRV in their peer group, and HRV increases between blocks of training signalling improved adaptation and later, performance.

There has also been a large amount of research into the relationship between HRV and stress, showing that acute stress reduces HRV. The amount of reduction depends on the size and duration of the stress source as well as the resilience of the person. The most common and important source of stress to athletes is pre-competitive anxiety and it is not known to what extent this impairs their performance.

Now, a study carried out by researchers in Brazil aims to bring together both HRV and competitive anxiety in a controlled competition environment to find out what exactly happens in the minds and physical performance of swimming championship participants.

What did they do?

The researchers recruited 41 male and 27 female 15-16 yr old swimmers at the Brazilian National Juvenile Championships. The tests were all performed around the 400m event.

30 mins before competition, the researchers used a standard questionnaire of 16 items to assess the swimmers’ Cognitive (mental) anxiety, Somatic (physical) anxiety and their self-confidence regarding their performance in the impending race. Based on their anxiety and confidence scores, the swimmers were separated into two groups of either Low or High competitive anxiety.

Following measures that included body weight and fat levels, the swimmers all had their heart rate variability (HRV) measured for 10 mins whilst sitting quietly. 10 mins later, they competed, followed by a 3 hour rest and relaxation period. They then had their HRV re-taken. Various HRV measures were calculated, but LnRMSSD (as used in ithlete) was the one used to assess relations to pre competition anxiety.

What can HRV tell us about pre-competitive anxiety and performance?

What did they find?

They found that the Low anxiety group had considerably higher average HRV after the race (78 ± 6 on the ithlete scale) compared to the High anxiety group (66 ± 8 on the ithlete scale). These results suggest that pre-competitive mental and physical anxiety are negatively associated with the post-race HRV of swimmers.  In fact, 36% of the change in HRV from before to after the race could be due to anxiety.

They did not find a significant difference regarding race performance between the two groups, they also did not find a relation between self-confidence, although they were expecting more confident swimmers to have higher HRV.

What does it mean?

Although clear in its main conclusion that high anxiety before competition leads to a larger reduction in HRV afterwards, this study leaves open the question as to whether managing anxiety through techniques such as imagery, visualisation or slow deep breathing can help anxious athletes either perform better or recover faster.

By Simon Wegerif

Influence of Competitive-Anxiety on Heart Rate Variability in Swimmers. Leonardo S. Fortes 1, Bruna D. V. da Costa1, Pedro P. Paes 1, José R.A. do Nascimento Júnior 2, Lenamar Fiorese 3 and Maria E.C. Ferreira4. Journal of Sports Science and Medicine (2017) 16, 498-504