BMR is estimated with Mifflin-St Jeor formula and energy expenditure (EE) using Keytel’s model Mifflin et al. PARAMETERĮnergy expenditure (EE) divided into Basal Metabolic Rate (BMR) and activity related energy expenditure. Table 1: Summary of time-domain HRV parameters calculated by Kubios HRV software. In addition, the square root of SI is taken to transform the tailed distribution of SI values towards normal distribution.
#POINTCARRE ANALYSIS SERIES#
In order to make SI less sensitive to slow changes in mean heart rate (which would increase the MxDMn and lower AMo), the very low frequency trend is removed from the RR interval time series by using the smoothness priors method Tarvainen et al 2002. The AMo is obtained as the height of the normalised RR interval histogram (bin width 50 msec) and MxDMn as the difference between longest and shortest RR interval values. The mode Mo is simply taken as the median of the RR intervals. Where AMo is the so-called mode amplitude presented in percent, Mo is the mode (the most frequent RR interval) and MxDMn is the variation scope reflecting degree of RR interval variability (see Fig. The Baevsky’s stress index (SI) is computed according to the formula Baevsky 2009 Another geometric measure is the TINN which is the baseline width of the RR histogram evaluated through triangular interpolation, see Fig. In order to obtain comparable results, a bin width of 1/128 seconds is recommended Task Force 1996. total number of RR intervals) divided by the height of the histogram which depends on the selected bin width. The HRV triangular index is obtained as the integral of the histogram (i.e. In addition to the above statistical measures, there are some geometric measures that are calculated from the RR interval histogram. For stationary RR series and SDSD equals the root mean square of successive differences (RMSSD) given byĪnother measure calculated from successive RR interval differences is the NN50 which is the number of successive intervals differing more than 50 ms or the corresponding relative amount Is a measure of short-term (beat-by-beat) variability. SDNN reflects the overall (both short-term and long-term) variation within the RR interval time series, whereas the standard deviation of successive RR interval differences (SDSD) given by The standard deviation of RR intervals (SDNN) is defined as Several heart rate variability parameters that measure the variability within the RR time intervals in time-domain exist. Where denotes the value of ‘th RR interval. The mean RR interval ( ) and the mean heart rate ( ) are then defined as Let the RR interval time series include successive beat intervals, i.e. The time-domain methods are derived from the beat-to-beat RR interval values in time domain. The figure also shows for a 60-min training session the link between TRIMP value and training load. The link between TRIMP/min values and training intensity is shown in Fig. The cumulative sum of TRIMP/min, on the other hand, gives an index of training load accumulation. TRIMP/min can be used as an index of training intensity. In Kubios HRV, we compute the TRIMP using beat-to-beat HR values, and thus, instantaneous value of TRIMP (TRIMP/min) can be reliably derived. TRIMP accumulation rate increases exponentially as a function of exercise intensity, modelling lactate accumulation during exercise. Where is duration of exercise and is a heart rate reserve ratio. 1990, which is defined for male and female subjects separately as The TRIMP can be computed according to exponential Banister’s model Morton et al. Training impulse (TRIMP) is a rather commonly used index for training volume. The instantaneous values of EE can be used to assess how energy expenditure is distributed throughout the day. In Kubios HRV, we compute the EE using beat-to-beat HR values, and thus, the instantaneous EE (kcal/min) can be realiably derived. The energy expenditure computations are based on heart rate, body weight, height and age. 1990 and 2) activity related energy expenditure (EE) computed using the Keytel’s formula Keytel et al.
#POINTCARRE ANALYSIS SOFTWARE#
In Kubios HRV software the energy expenditure is divided into: 1) basal metabolic rate (BMR) computed using the Mifflin-St Jeor equation Mifflin et al. Heart rate based energy expenditure models, provide a reliable estimates of daily energy expenditure.