Combined aerobic and resistance training Combined aerobic and resistance training
and vascular function
and vascular function : : effect of aerobic effect of aerobic exercise before and after resistance training exercise before and after resistance training
祁崇溥 老師
臺北醫學大學通識教育中心專任體育講師 國立海洋大學食品科學系博士生
Article introduction Article introduction
Title: Combined aerobic and resistance training and vascular function: effect of aerobic exercise before and after resistance training
Author: Takanobu Okamoto, Mitsuhiko Masuhara, and Komei Ikuta
Published: September 13, 2007
Journal: Journal of Applied Physiology
Impact factor: 3.632
Motivation Motivation
Does aerobic exercise before RT positively not
affect vascular function
!?
What is Shear stress ? What is Endothelial cell ?
What is NO ( nitric oxide) ?
Aerobic exercise was performed after RT in almost all previous studies
Aerobic exercise before RT as previously examined could improve vascular function
is unknown
How aerobic exercise & RT effect on cardiovascular respectively ?
How about combined ?
short - term short - term
aerobic training resistance training
improve
endothelium-dependent nitric oxide (NO)- mediated vascular function in both conduit and
resistance vessels
AE bf / aft RT ?
Q:
Might these effects positively influence
when the AE takes place before RT?!
Methods Methods
Subjects Subjects
• 33 healthy nonsmoking males and females (11 male, 22 female; age 18.6±0.1 yr)
• Some subjects who had an exercise habit in the past were included, most of the subjects had not exercised for more than 1 yr and had not engaged in RT.
• Health examination : anamnesis, blood pressure, dipstick test, electrocardiogram, and chest X-ray. Blood
examination was not performed. No abnormal
findings
Subjects were randomly assigned 3 groups :
AE before RT (BRT, n = 11, 4 male & 7 female) AE after RT (ART, n = 11, 4 male & 7 female)
remain sedentary (SED, n = 11, 3 male & 8 female)
Table.1 from <Combined aerobic and resistance training and vascular function: effect of aerobic exercise before and after resistance training > J Appl Physiol 103: 1656, 2007.
Study Design Study Design
• Combination of treadmill running and RT performed and proceeded twice weekly between 2:00 and 6:00 PM.
• SED group were instructed not to alter their normal
activity levels throughout the study period.
• Running :set at 60% of the target heart rate using a heart rate monitor
• The Carbonen method (also called Karvonen method) :
target HR=[ maximal HR (220-age) -resting RT ] × 0.6 (exercise intensity 60%) + resting HR
• BRT group run before RT for 20 min
• ART group run after RT for 20 min
Aerobic Training
Aerobic Training
Resistance Training Resistance Training
• 2 times/ week for 8 wks
• Training program:chest press, arm curl, seated row, shoulder press, leg curl, leg press, and abdominal bent (sit up)
• Training load:80% of 1RM;5sets;8 –10 repetitions / set
• Rest period:2min / set to set
• 1RM need to be measured again after 4 wks from the start
of training, and the load are adjusted based on a new 1RM
Measurements Measurements
* brachial-ankle pulse wave velocity (baPWV)
* brachial artery flow-mediated dilation (FMD)、
normalized FMD
* brachial blood pressure and heart rate
* brachial artery hemodynamics
( brachial artery’s diameter、mean blood velocity、BF、
hyperemic BV、hyperemic BF;VC;VR )
before training (baseline)
after training (8wks, completion of training)
after detraining (4wks, completion of detraining)
Results Results
• Changes in 1RM
• Changes in baPWV
• Changes in brachial artery FMD and normalized FMD
• Changes in brachial blood pressure and heart rate
• Changes in brachial artery hemodynamics
Changes in 1RM Changes in 1RM
No significant differences in the chest press
BRT
Shoulder press13%
Seated row 15%
Arm curl 33%
Leg press 16%
Leg curl 16%
Chest Press
18%
ART
Shoulder press17%
Seated row 16%
Arm curl 52%
Leg press 39%
Leg curl 29%
Chest press
20%
Changes in
Changes in baPWV baPWV
*baPWV may provide information qualitatively similar to that derived from central arterial stiffness
Fig . from <Combined aerobic and resistance training and vascular function: effect of aerobic exercise before and after resistance training > J Appl Physiol 103: 1657, 2007.
Changes in brachial artery FMD and normalized FMD Changes in brachial artery FMD and normalized FMD
Fig . from <Combined aerobic and resistance training and vascular function: effect of aerobic exercise before and after resistance training > J Appl Physiol 103: 1657, 2007.
Changes in brachial blood pressure and heart rate Changes in brachial blood pressure and heart rate
Table from <Combined aerobic and resistance training and vascular function: effect of aerobic exercise before and after resistance training> J Appl Physiol 103: 1658, 2007.
Changes in brachial artery
Changes in brachial artery hemodynamics hemodynamics
Table from <Combined aerobic and resistance training and vascular function: effect of aerobic exercise before and after resistance training> J Appl Physiol 103: 1657, 2007.
Discussion Discussion
RT & AE & Vascular function RT & AE & Vascular function
Previous studies :
• That simultaneous endurance and resistance training may negate potentially negative effects of arterial
stiffening. - Cook et al. (2006)
• Aerobic exercise after RT might prevent the stiffening of carotid arteries associated with RT in healthy
young men. - Kawano et al. (2006)
arterial stiffness
BRT no changed ! ART reduced !
FMD
ART increased !
* Aerobic exercise before RT does not favorably affect vascular function and do not support the notion that aerobic exercise always exerts a beneficial effect on vascular function
* That 8 wks of aerobic exercise training performed after RT resulted in reduced arterial stiffness in healthy young adults
Consistent with the study !
aerobic exercise combined with RT improves endothelial NO
function -
Green et al. (2004)FMD:
ability of a conduit artery internal diameter BF and shear stress
BRT’s FMD no change
BRT does not promote arterial flexibility
ART ‘s FMD increased
BRT seems to improve vascular function
but
That significant changes in FMD and PWV in the ART group
might be explained by greater cardiovascular benefits
?
Controversial point Controversial point
• RT does not confer unfavorable effects on vascular function! -Rakobowchuk. et al(2005)
• RT does it! -Bertovic. et al (1999), Cortez-Cooper et al.(2005), DeVan et al.(2005), Ebenbichler et al.(2001),
Miyachi et al.(2004), Okamoto et al.(2006).
• Further investigations must assess the beneficial effects
of resistance training on vascular function
Brachial artery diameter Brachial artery diameter
The expansion of the femoral arterial lumen diameter in previously sedentary middle-aged and elderly men after 3 mo
of aerobic exercise intervention
- Dinenno et al. (2001)
It reported that RT enlarges brachial and femoral
artery diameter
- Miyachi et al. (2005), Rakobowchuk. et al(2005)
Both aerobic exercise and RT increase brachial or femoral arterial diameter, enlargement at
the level of the major conduit arteries
Arterial expansion seems to relate to structural remodeling or reduced vascular smooth muscular tone
and helps to decrease peripheral arterial stiffness
ART BRT ?
?
HR & blood pressure HR & blood pressure
HR&BP are remained unchanged among the 3 groups
The effects of sympathetic nervous tone after resistance training cannot be excluded. - Maiorana et al. (2000)
• Aerobic exercise suppresses increases in blood pressure
- Martin et al. (1990), Paffenbarger (1993)
• Aerobic exercise before RT might suppress a subsequent increase in blood pressure induced by RT
• The favorable effects of aerobic exercise are negated by
subsequent RT
The alterations in vascular function in the ART group primarily resulted from
changes in arterial distension
Brachial artery
Brachial artery hemodynamics hemodynamics
Previous studies :
• Calf VR is reduced after aerobic exercise.
-Halliwill et al. (1996)
• Short term RT increases femoral BF and VC in healthy middle aged and older adults. -Anton et al.(2006)
• RT affects basal limb perfusion through a mechanism underlying its effects on glucose uptake. -Anton et al.
(2006)
In this study :
• The brachial MBV, hyperemic BV, BF, hyperemic BF, VC, and
VR in the BRT and ART groups significantly changed from baseline.
• Aerobic exercise before RT does not seem to improve vascular function
Result :
• The hemodynamic improvement induced by aerobic and resistance training is important.
• The physiological mechanisms underlying the changed
hemodynamics in RT remain obscure.
Previous studies :
• The growth hormone (GH) response to resistance exercise is attenuated by prior endurance exercise.
-Goto et al. (2005)
• The strength gains were consistently smaller in a group that performed combined training compared with a group that had performed only high intensity RT.
-Kawano et al. (2006)
Combined training may favorably affect vascular function but suppress increases in muscular strength
1 RM 1 RM
Conclusion Conclusion
• Aerobic exercise after, but not before RT improves vascular function.
• Speculating that habitual RT promotes an increase in
blood flow through an impact on skeletal muscle mass,
it does not improve vascular function.
Further study Further study
• To determine the effects of resistance exercise on arterial hemodynamics and vascular function.
• To measure aerobic fitness.
• To measure GH reponse.
Functions of GH
y Increases muscle mass through the sarcomere hyperplasia
y Reduces liver uptake of glucose
摘錄自網路< 流體力學的基本原理&血液基本特性>
在人體的循環系統中,內皮細胞形成單一細胞厚度 的血管內壁,提供血液與其他系統間極重要的生理介
面,藉由內皮細胞分泌特殊細胞訊息分子,以調控血管 的生理功能,並負責營養物質的穿透與傳輸,扮演著血 液與血管間平衡循環的角色。
圖摘自<內皮細胞> 維基百科
NO在血管內皮是使血管的平滑肌細胞放鬆而擴張 血管,可以降低血壓。
摘錄自<1998 年諾貝爾生理或醫學獎一氧化氮的重 要發現與應用>黃頂立 美國哥倫比亞大學生物有機化學博士正常人類內皮細胞可持續分泌一氧化氮以維持血管 恆定舒張。它可降低切應力,減低血管阻力,改善局部 血流。一旦內皮依賴型血管擴張受損,可見於傳統的心 血管危險因子(甚至在無動脈硬化時業可見到 )。
摘錄自<精氨酸--一氧化氮路徑:從基礎到臨床應用>林廷燦 屏東市國仁醫院 內科部