Download Cardiovascular Response to Strength Training

Cardiovascular Response to
Strength Training
Chronic Adaptation at Rest
Decrease rest Heart rate (HR) and Blood
pressure (BP)
Change in Blood lipid
Change in cardiac morphology, Stroke volume
(SV), Cardiac output (CO)
Adaptation at rest
Heart rate
Blood pressure
systolic
diastolic
Double product
Stroke volume (absolute)
Relative BSA
Relative LBM
Cardiac systolic function
Cardiac diastolic function
Lipid profile
total cholesterol
HDL-C
LDL-C
↓or no change
↓or no change
↓or no change
↓or no change
↑or no change
No change
No change
↑or no change
No change
↓or no change
↑or no change
↓or no change
Heart Rate (HR)
Short-term longitudinal studies report
decreases of from 5 to 12%
Decrease resting HR is normally attributed to a
combination of increased parasympathetic and
diminished tone
Nervous System Regulation of Heart
Rate
The spontaneous activity of
autonomic nerves is regulated
by different types of sensory
receptors in the body that
monitor physiological function
NTS: nucleus tractus
solitarius (NTS) of the
medulla
Receptor afferents: Sensory
receptors that are involved in
regulating blood pressure are
called baroreceptors
Blood Pressure (BP)
Pulse pressure
– Difference between systolic and diastolic
Pulse Pressure = Systolic - Diastolic
Mean arterial pressure (MAP)
– Average pressure in the arteries
MAP = Diastolic + 1/3(pulse pressure)
Blood Pressure (BP)
Highly trained athletes to have
average or lower than average
systolic and diastolic blood
pressure (SBP/DBP)
Mean changes in resting
systolic and diastolic blood
pressures after two months of
combined strength and
endurance exercise
Misconceptions
Strength training causes hypertension?
Some athletes observed hypertension may be:
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–
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Essential hypertension
Chronic overtraining
Use of androgens
Large gains of muscle mass
Possible Explanations
Increase body fat
Increase body salt
Alternations of the
sympathoadrenal drive
Adrenergic and
Cholinergic Receptors
in Blood Vessels
Double Product
DP=HR × SBP
An estimate of myocardial work and is
proportional to myocardial oxygen
consumption
Longitudinal strength training decrease the rest
double product
Indicating a decrease in myocardial oxygen
consumption at rest as an adaptation to
strength training
Stroke Volume
Increase absolute stroke
volume is due to a greater
diastolic left ventricular
diameter and a normal
ejection fraction
the stroke volume is 75
ml for an untrained man
at rest, and 105 ml for a
trained athlete at rest
Lipid Profile
The effects of strength training on lipid profile
is controversial in male, female subjects, also
in longitudinal and cross-section designs
These studies be criticized:
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–
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Inadequate control of age
Diet
Training regimes
Androgen use
Single blood sample
Change in body composition
Effect from last training session
Lipid Profile
Programmes using 8-12 rep. per set of an
exercise and short rest periods may more
positively affect lipid profile than heavy
resistance for 1-6 rep. per set and long rest
period.
Lipid Profile and Intensity of Exercise
Lipoprotein
measurement
Low amount,
moderate
intensity
Low amount,
high intensity
High amount,
high intensity
p*
LDL cholesterol (mg/dL)
+5.1
+2.1
-3.6
0.01
HDL cholesterol (mg/dL)
+1.1
+.8
+3.8
0.005
Triglycerides (mg/dL)
-50.4
-13.3
-20
0.002
LDL particles (nmol/L)
-59
-6
-96
0.002
Small LDL particles
(mg/dL of cholesterol)
+4.7
+1.3
-9.8
<0.001
Lipoprotein
measurement
Low amount,
moderate
intensity
Low amount, High amount,
high
high
intensity
intensity
p*
Size of LDL particles
(nm)
+0.1
+0.1
+0.3
0.05
Large VLDL particles
(mg/dL of
triglycerides)
-42
-13.5
-14.5
0.03
Size of VLDL
particles (nm)
-6.5
-4.1
-1.1
0.04
Large HDL particles
(mg/dL of cholesterol)
+0.9
+0.9
+4.9
0.02
Size of HDL particles
(nm)
0
0
+0.2
0.02
•p for intention-to-treat analysis, comparing changes in high-amount, high-intensity group with changes in
•control patients.To download table as slides, click on slide logo below
Cardiac morphology adaptations at rest
Wall Thickness
Left ventricle
Septum
Right ventricle
Chamber volume
Left ventricle
Right ventricle
Left ventricular mass
Absolute
Relative to:
BSA
LBM
↑↑↑
↑↑↑
No change
↑↑or no change
↑↑or no change
No change
↑↑or no change
↑↑or no change
No change
↑ ↑or no change
No change
↑↑ ↑or no change
No change
No change
↑↑or no change
No change
No change
↑or no change
Cardiac Wall Thickness
Diastolic posterior left
ventricular (PWTd) and
intraventricular septum
(IVSd) most common
use to determine wall
thickness using
echocardiographic
techniques
Highly trained male’s absolute PWTd and
IVSd is increased due to strength training
This increase is reduced if examine relative to
body surface area or lean body mass
Increased wall thickness is caused by
intermittent elevated BP during training and
related to the caliber of athlete and to the
strength training intensity and volume
Chamber Dimensions
As an indication of volume overload on the heart
Commonly found in endurance athletes
Bodybuilder greater left ventricular internal
dimensions, in absolute or relative to body
surface or lean body mass but not in Weightlifter
Strength-training do not increase cardiac
chamber size which may increase after
bodybuilding-type programmes
Left ventricular mass
National/international calibre ＞less calibre
Bodybuilder=weightlifter > control
Bodybuilder ↑chamber size and wall thickness
Weightlifter ↑chamber size
↑is related to the intensity and calibre of athletes
Features Distinguishing Athletic Heart
Syndrome From Cardiomyopathy
Feature
Athletic Heart Syndrome
Cardiomyopathy
.
Left ventricular hypertrophy
< 13 mm
> 15 mm
Left ventricular end-diastolic
diameter
< 60 mm
> 70 mm
Diastolic function
Normal (E:A ratio > 1)
Abnormal (E:A ratio < 1)
Septal hypertrophy
Symmetric
Family history
None
Asymmetric (in
hypertrophic
cardiomyopathy)
May be present
BP response to exercise
Normal
Normal or reduced
systolic BP response
Deconditioning
Left ventricular
hypertrophy regression
No left ventricular
hypertrophy regression .
Systolic Function
Measurement
– % fractional shortening (%FS)
– Ejection fraction (Ef) (normal =55-77%)
– Velocity of circumferential shortening (VCS)
Greater %FS in athletes than control (32 vs.
37%)
Most data show strength training have no
effect on systolic function
Diastolic Function
Abnormalities in diastolic function are
associated with cardiac hypertrophy due to
hypertension
Power-lifters
– Greater absolute and relative to body surface area
left ventricular mass
Factors Increasing Diastolic
Pressure
Impaired Ventricular Relaxation
Increased Ventricular Stiffness
Hypertrophy
Hypertrophy
Myocardial ischemia
Hypertension
Hypertension
Collagen deposition and fibrosis
Collagen deposition and fibrosis
Cellular disarray
Regional asynchrony
Myocardial infiltration
Increased preload, afterload
Pericardial constriction or restriction
Abnormal calcium flux
Tachycardia
Acute response
HR, SBP, and DBP increase during the
performance of dynamic heavy strength
exercise
Highest HR and BP normally occur during the
last repetitions of a set to volitional fatigue
HR, BP and CO response increase with
increased active muscle mass
The response is not linear
Acute response of strength exercise
relative to rest
Position of repetition
Concentric
Eccentric
Heart rate
Blood pressure
Systolic
Diastolic
Intra-thoracic pressure
Cardiac output
Stroke volume
↑
↑
↑
↑
No change?
No change?
↑
↑
↑
↑
↑?
↑?
Strength training with Valsalva maneuvers
which elevate intra-thoracic pressure would
lead to a greater BP
Concentric portion of exercise may
mechanically induce an increase in peripheral
resistance
The increased intra-thoracic pressure may have
a protective function for the cerebral blood
vessels
Factors result in an
increase in preload (by
causing fluid retention
and venous constriction)
and an increase in heart
rate and contractility,
thereby raising cardiac
output
Chronic adaptation during strength
exercise
Lower maximal systolic and diastolic intraarterial BP and HR max during strength
training in body builders (absolute and relative
workload)
Cross-section and longitudinal data have
shown that strength training can result in a
lower pressor response and lower myocardial
oxygen consumption
Decrease BP during activity resulting in a
decreased after load on the left ventricle
Forceful Vasalva manoeuver may elevate
intrathoracic and intra abdominal pressure in
power lifter that lower CO
VO2 max increase in some but not all strength
programmes
Factors affecting VO2 max after strength
training
– Total training volume
– Rest periods between sets
– Large vs small muscle mass exercise
Adaptation during exercise due to
strength training relative to normals
Heart rate
Blood pressure
Systolic
Diastolic
Double product
Cardiac output
Stroke Volume
VO2max
↓
↓ or no change
↓ or no change
↓
↑
↑
↑
Conculsion
Strength training does not result in a pressor
response that has an impact upon the
cardiovascular system
Long-term performance of strength training
can result in positive adaptations of the
cardiovascular system at rest and during work
The extent of these adaptations may in large
part be dependent upon the volume and
intensity if strength training performed
Discussion
How do you design a resistance training for a lower
fitness, middle-aged male who could be able to
reduce his blood pressure from 138/95 to 120/80.
What do you think why an intense strength training
could change the preload and afterload of heart (e.g.
85% 1RM).
What would be a possible explanation regarding the
effect of weight training on autonomic nerve system’s
responses and adaptations.