Heart Rate Variability and Direct Current Measurement Characteristics in Professional Mixed Martial Arts Athletes

Abstract

This study’s purpose was to examine heart rate variability (HRV) and direct current potential (DC) measures’ sensitivity and correlations between changes in the acute recovery and stress scale (ARSS) and the previous day’s training load. Training load, HRV, DC and ARSS data were collected from fourteen professional mixed martial arts athletes (32.6 ± 5.3 years, 174.8 ± 8.8 cm, 79.2 ± 17.5 kg) the following morning after hard, easy and rest days. Sensitivity was expressed as a signal-to-noise ratio (SNR, inter-day typical error (TE) or coefficient of variation (%CV) divided by intra-day TE or %CV). Correlations between HRV, DC and ARSS with training load were also examined. The SNRs for the various HRV and DC measures were acceptable to good (1.02–2.85). There was a 23.1% CV average increase between measures taken between different locations versus the same location. Training load changes were not correlated with HRV/DC but were correlated with ARSS stress variables. Practitioners should be aware of HRV/DC variability; however the daily training signal was greater than the test-retest error in this investigation. Upon awakening, HRV/DC measures appear superior for standardization and planning. HRV and DC measures were less sensitive to the previous day’s training load than ARSS measures.

Training Load, Heart Rate Variability, Direct Current Potential and Elite Long Jump Performance Prior and during the 2016 Olympic Games

“…Heart rate variability and DC were assessed using Omegawave® (Omegawave Oy, Espoo, Finland) which appears to have adequate reliability and sensitivity as a measurement device (Coyne et al, 2020a;Parrado et al, 2010;Valenzuela et al, 2020). As recommended by the manufacturer, athletes self-administered the HRV/DC assessment in a supine position 15-30 minutes after waking and before ingesting food or liquid in the morning before training.…”

“…HRV is the variability between successive heart beats (RR interval) and is considered an indicator of the autonomic nervous system (Buchheit, 2014). Less researched is DC, which is measured through electrodes placed on the scalp or the forehead and thenar eminence and has been suggested to be an indicator of central nervous system status, is defined as very slow brainwave activity (0-0.5 Hz) and appears to be correlated with electroencephalography measures (Coyne et al, 2020a;Valenzuela et al, 2020). The autonomic and central nervous system status of athletes seems to be worthwhile for athletics coaches to be aware of to inform training (Buchheit, 2014;Peterson, 2018).…”

“…However, practitioners should be aware that there may not be a positive relationship between RMSSD and competition performance in elite athletes, which is different and even opposite to national or well-trained athletes (Plews et al, 2013;. Regarding DC, the authors were unable to find any recommendations for monitoring this measure in athletes despite recent publications examining DC's measurement characteristics (Coyne et al, 2020a;Valenzuela et al, 2020).…”

Quantification of training load distribution in mixed martial arts athletes: A lack of periodisation and load management

“…The absence of this practice in our data results in the static load between weeks and may also explain the lack of changes in fatigue. Comparisons to other sports show daily sRPE of MMA is low [48,49] and most days would be classed as 'easy' according to the arbitrary definition recently suggested for MMA [18]. The daily load provided therefore may not be great enough to cause sufficient strain to bring about fatigue beyond the acute stage, reducing the likelihood of optimal fatigue-recovery-adaptation.…”

“…Indeed, reports to date are limited to retrospective questionnaires [14,15] and a case-study account in which a participant was preparing for a now defunct rule set and competition format [16]. More recent studies do provide the subjective weekly load of MMA pre-competition training [17] and suggest training load ratings for 'hard' and 'easy' days [18]. Whilst these studies measured training load via sessional rating of perceived exertion (sRPE) [19] neither described how these loads are achieved, the intensities of training methods nor how training is modified for a bout.…”