Post on 21-Jan-2017
Dr Roger Ramsbottom
Department of Sport and Health SciencesOxford Brookes UniversityUnited Kingdom
11th Congress of Sport and Physical EducationPontevedra, Espaňa, 6-9 May, 2015.
THE UTILITY OF HEART RATE MEASURES IN SPORT AND EXERCISE SCIENCE
EXERCISE SCIENCE
ESTIMATION OF CARDIORESPIRATORY FITNESS FROM THE SUBMAXIMAL HEART RATE RESPONSE
ESTIMATION OF CARDIORESPIRATORY FITNESS FROM THE SUBMAXIMAL HEART RATE RESPONSE
Heart rate (b min-1)
Oxy
gen
upta
ke (L
min
-1) VO2max*
y = mx + cr = 0.998
*Aerobic fitness = maximal aerobic power (or VO2max)
VO2 Heart rate
1.10 109
1.35 123
1.55 140
2.20 156
ESTIMATION OF ENERGY EXPENDITURE FROM THE SUBMAXIMAL HEART RATE
Heart rate (b min-1)Oxy
gen
upta
ke (L
min
-1)
y = mx + cr = 0.998
*kJ 1.0 L O2 = 21 kJ energy
With an individual relationship between oxygen uptake and heart rate – the rate of energy expenditure can be estimated*.
MOUNT SNOWDON, WALES (1085-M) ESTIMATED ENERGY EXPENDITURE
Distance 25.51 kmMean HR 126 b min-1
EE 4,976 kcal (20.8 MJ)Duration 9 hrs 29 min
MOUNT SNOWDON, WALES (1085-M) HEART RATE RESPONSE AND WALK PROFILE
THE HEART: CARDIAC CONDUCTION SYSTEM
SA node ~ 60-100 bpm - sets the pace of the heartbeatAV node ~ 50 bpm - delays the transmission of action potentials
70-80/min
40-60/min
20-40/min
Intrinsic autorhymicity is influenced by parasympatheic and sympathetic neural input
PARASYMPATHETIC AND SYMPATHETIC INNERVATION OF THE HEART
PARASYMPATHETIC AND SYMPATHETIC INNERVATION OF THE HEART
HEART RATE VARIABILITY (HRV)
Different Heart Rate Variability (ms) in two individuals with similar Heart Rate (b min-1)
R-R Interval
TIME DOMAIN FREQUENCY DOMAIN ANALYSIS
SDNN:Standard deviation of the R-R interval in milliseconds.
Long-term control of HRV
RMSSD:Square root of the mean of the squares of successive R-R interval differences
Short-term control of HRV
High Frequency: Vagal activity
Low Frequency: Baroreceptor reflex
activity
Very Low Frequency: e.g. Renin-angiotensin
Autoregression analysis
POINCARÉ PLOTS
Quantitative measures:
SD1: Short-term HRV (SD of plot data along axis A)
SD2: Long-term HRV (SD of plot data along axis B) SD12 : (Poincaré dimension)Quantitative description of entire plot
A B
SD1 Measure of instantaneous beat-to-beat variability
SD2 Quantifies complex, long-term variability
STUDY I: SUBJECTS
Activity level
n Mean Supine Heart Rate
(b min-1)
Age (years)
Body Mass(kg)
Height (m)
Moderate 20 73(s=10)
26.1 (s=6.8)
67.5 (s=15.9)
1.66 (s=0.08)
High 20 59**(s=5)
23.8 (s=4.9)
63.4 (s=7.7)
1.66 (s=0.05)
**P<0.01Gilder and Ramsbottom (2008a) Measures of cardiac autonomic control in women with differing volumes of physical activity J. Sports Sciences, 26 (7): 781-786.
METHOD: MEASUREMENT OF HEART RATE VARIABILITY (HRV)
Polar S810i
Supine rest: 20
minutes of R-R
collection
Standing: 5 minutes of R-R collection
R-R data: HRV
Analysis
Time Domain:SDNN
RMSSD
Frequency Domain:(Autoregression analysis)
LF & HF LF/HF ratio (%)
Poincaré:SD1, SD2
RESULTS: HRV - MODERATE VERSUS HIGH PHYSICAL ACTIVITY GROUPS
Group
Moderate
High
RRI
827
1011**
SDNN
42.6
71.8**
RMSSD
42.1
82.2**
HF
230
515*
SD1
29.8
58.3*
SD1/SD2 ratio
0.39
0.49*
* P<0.05, **P<0.01
Each Poincaré plot shows 1000 R-R intervals
Participant A: Physical activity > 3 sessions per week, > 60 min; SD1 47.0 ms, SD2 87 ms, SD1/SD2 0.54
Participant B: Physical activity 1 session per week, > 30 min; SD1 11.9 ms, SD2 62.1 ms, SD1/SD2 0.19
POINCARÉ PLOTS: OVERTRAINING
Altered Poincaré plot shape in overtrained athletes (Mourot et al. 2004)
Trained Overtrained 1 Overtrained 2
R-R
Mourot et al. (2004) Decrease in heart rate variability with overtraining: assessment by the Poincaré plot analysis. Clin Physio Funct Imaging 24: 10-18
POINCARÉ PLOTS: CONGESTIVE HEART FAILURE
Plot shape indicates cardiac health status (Woo et al., 1994)
Normal Congestive Heart Failure
NA: 244 pg mL-1 NA: 750 pg mL-1Plasma NA:Normal range:150-300 pg mL-1
STUDY 2: HRV MAY INDICATE THE LACTATE AND VENTILATORY THRESHOLDSDi Michele et al. (2012) Estimation of the anaerobic threshold from the heart rate variability threshold in an incremental swimming test J. Strength & Cond. Res. 26 (11): 3059-3066.
James et al. (1989) Determination of anaerobic threshold by ventilatory frequency Int. J. Sports Med. 10 (3): 192-196.
Karapetian et al. (2008) Use of heart rate variability to estimate LT and VT Int. J. Sports Med. 29: 652-657.
Sales et al. (2011) Noninvasive method to estimate anaerobic threshold in individuals with type 2 diabetes Diabetology & Metabolic Syndrome 3: 1
HOW IS HRV DETERMINED?
Karapetian et al. (2008) Visual inspection …’point at which there was no further decline in HRV, thus indicating vagal withdrawal. Thus, this HRV deflection point was defined as the HRVT’.
Sales et al. (2011) ‘For the determination of the HRVT, a stabilization point lower than 3 milliseconds (ms) was adopted for the vagal activity indices (SD1 and RMSSD) plotted against the absolute workload’.
DATA FROM INCREMENTAL CYCLE ERGOMETRY
Work rate(W)
0306090
120150180210240
57.127.812.510.85.84.22.62.73.4
RMSSD(ms)
Blood lactate(mmol L-1)
VO2
(L min-1)VCO2
(L min-1)SD1(ms)
40.919.9
97.84.23
1.92
2.5
1.61.41.61.21.72.34.16.2
12.4
0.310.841.071.391.672.112.372.663.03
0.280.710.921.281.522.042.402.893.41
LACTATE THRESHOLD (0.4 MMOL L-1 ABOVE BASELINE)
0 50 100 150 200 250 3000.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
Work rate (w)
Blo
od L
acta
te C
once
ntra
tion
(mm
ol/L
)
Blood lactate(mmol L-1)
1.61.41.61.21.72.34.16.212.4
LT - 0.4 mmol L-1 sustained increase above baselineLT at 120 W
rest
move away from baseline lactate concentration >0.4 mmol L-1
VENTILATORY THRESHOLD VT1 (VCO2 PLOTTED AGAINST VO2)
0.50 1.00 1.50 2.00 2.50 3.00 3.500.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
f(x) = 1.50277442022907 x − 1.13296235684257R² = 0.998009535784683
f(x) = 0.992795801362949 x − 0.12393731882071R² = 0.99808678042964
VO2
(L min-1)VCO2
(L min-1)0.310.841.071.391.672.112.372.663.03
0.280.710.921.281.522.042.402.893.41
rest
VT1 breakpoint at 120 WVT1 at 120 W
HRV THRESHOLD (RMSSD VERSUS WORK RATE)
0 50 100 150 200 250 3000
5
10
15
20
25
30
RMSSD versus Work Rate
Work Rate (W)
RM
SS
D (m
s)
HRVT stabilization below 3 ms is at 2.6 msHRVT at 180 W
RMSSD(ms)
57.127.812.510.85.84.22.62.73.4
rest
HRV THRESHOLD (SD1 VERSUS WORK RATE)
0 50 100 150 200 250 3000
5
10
15
20
25
SD1 versus Work Rate
Work Rate (w)
SD
1 (m
s)
SD1(ms)
40.919.99.07.84.23.01.92.02.5
HRVT stabilization below 3 ms is at 1.9 msHRVT at 180 W
rest
VENTILATORY THRESHOLD VT2 RESPIRATORY COMPENSATION POINT (VE PLOTTED AGAINST VCO2)
0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.000
10
20
30
40
50
60
70
80
90
f(x) = 32.8274485770427 x − 29.2804788918188R² = 0.997483169096688
f(x) = 17.5117538864979 x + 6.4770276967594R² = 0.995630657102024
VCO2
V E
VT2 breakpoint at 180 WVT2 at 180 W
VCO2
(L min-1)0.280.710.921.281.522.042.402.893.41
9.618.722.829.632.342.350.064.783.3
VE
(L min-1)Work rate
(W)0
306090
120150180210240
SUMMARYHEART RATE MEASURES CAN:
Estimate energy expenditure (kJ) during steady-rate submaximal exercise.
Estimate cardiorespiratory fitness (VO2max) based on the submaximal heart rate response.
Indicate the training status of an athlete.
Indicate cardiac autonomic health status in clinical populations.
May reflect the lactate and ventilatory thresholds during incremental exercise.