Content uploaded by Terje Gjøvaag
Author content
All content in this area was uploaded by Terje Gjøvaag on Apr 27, 2015
Content may be subject to copyright.
1
Short title: Resistance exercise and acute blood pressure responses
Acute hemodynamic and cardiovascular responses
following resistance exercise to voluntary exhaustion.
Effects of different loadings and exercise durations
Terje Gjovaag1, Asmund Krogh Hjelmeland2, Jonas Belstad Øygard2, Harald Vikne3, Peyman
Mirtaheri4
1Department of Occupational therapy, Prosthetics and Orthotics, Faculty of Health Sciences,
Oslo and Akershus University College, Oslo, Norway
2Department of Physiotherapy, Faculty of Health Sciences, Oslo and Akershus University
College, Oslo, Norway.
3Department of Health Sciences, Faculty of Medicine, University of Oslo, Norway
4Department of Industrial Development, Faculty of Technology, Art and Design, Oslo and
Akershus University College, Oslo, Norway
Corresponding author:
Terje Gjovaag
Department of Occupational therapy, Prosthetics and Orthotics, Faculty of Health Sciences,
Oslo and Akershus University College, Oslo, Norway
POB 4, St. Olavs plass,
N-0130 Oslo, Norway
E-mail: terje.gjovaag@hioa.no
2
ABSTRACT
Aim: Compare the acute hemodynamic and cardiovascular responses of high load/low repetition
resistance training (RT) to low load/high repetition RT.
Methods: Thirteen healthy men performed four sets of 4 repetition maximum (RM) and 20RM leg-
extensions without breath-holding. The RT was conducted in a randomized order and with 48 hours
between bouts. Non-invasive beat-to-beat systolic and diastolic blood-pressure (SBP/DBP) was
measured on the finger, while non-invasive cardiac output (CO) was assessed beat-to-beat by
impedance-cardiography.
Results: Mean ± SD resting SBP/DBP and CO were 126 ± 14/73 ± 9 mmHg and 5.6 ± 9 L min-1,
respectively. Exercise SBP/DBP values increased to 154 ± 22/99 ±18 and 203 ± 33/126 ± 19 mmHg
following 4RM and 20RM RT, respectively (compared to rest, all; p < 0.001), and 20RM SBP/DBP
values were higher than 4RM values (both, p < 0.001). The SBP increased from the first to the fourth
set of exercise following the 20RM load (p < 0.01), but not so for the 4RM load. Exercise SBP/DBP
values following the 4th rep of 20RM exercise (154 ± 18/91 ± 14), was similar to the 4RM values, but
different to the 20th rep of the 20 RM loading (both; p < 0.001). CO increased to 10.8 ± 2.6 and 13.9
± 2.2 L min-1, following 4RM and 20RM RT, respectively (compared to rest, both; p < 0.001) and
20RM CO was higher than 4RM CO (p < 0.01).
Conclusion: 20RM RT resulted in higher blood-pressure than 4RM RT when performed to voluntary
exhaustion. Differences in hemodynamic responses seems to be related to training duration and not to
difference in loading.
Keywords: blood pressure, cardiac output, strength training
The authors have no conflict of interest to disclose
3
Introduction
When designing resistance training programs, variables like the load, number of repetitions lifted,
number of sets and exercises performed, length of rest periods between sets and exercises, can be
manipulated to stress the muscles in particular ways and thus optimize specific training adaptations in
the exercised muscle. In this respect, it is not uncommon that RT with high repetition/low or medium
load is used to improve local muscular endurance (e.g.1) whereas RT with low repetition/high load is
frequently used to improve muscle strength and power (e.g.2).
Choosing between low rep/high load or high rep/low load RT is, however, not the only factors to
consider when designing a RT program for recreation exercise, rehabilitation and for prophylaxis
purposes. Caution has been raised concerning the very high blood pressure values that can be attained
in the left ventricle during heavy RT (3,4). In this regard, it is argued that RT with a load of 40-60 % of
maximum voluntary contraction (MVC) with 15-20 repetitions result in only modest increases in
blood pressure (5). In contrast, very high systolic and diastolic blood pressure values (320/250 mmHg)
are reported when multiple sets of 90-95 % of MVC are performed to exhaustion (6). Arterial
hypertension during RT may, however, be reduced when the participants perform the exercise with an
open glottis, that is avoiding breath-holding during the RT (7).
There are, however, few studies that have investigated the hemodynamic responses to heavy and
moderate loading RT performed without breath holding. In the light of the increasing use of different
RT programs in exercise rehabilitation and prophylaxis programs of both young and older individuals
(8, 9), there is a need to compare the acute blood pressure responses of low rep/high load (4RM) RT to
high rep/low load (20RM) RT.
The relationship between RT with similar load, but different number of repetitions also need to be
investigated to clarify effect of exercise load versus duration. In addition, although cardiac output
(CO) and systemic vascular resistance (SVR) are major determinants of the blood pressure during
exercise, the acute effects of RT with different loadings on CO and SVR has been little investigated.
Consequently, the main goals of the present study is to compare the acute blood pressure, CO and
SVR responses of RT with moderate and heavy loading protocols and to examine the effects of
exercise volume, duration and resistance.
4
Materials and methods
Participants
Thirteen normotensive, healthy and non-smoking males volunteered to participate in the present study.
They did not have any musculoskeletal diseases or other conditions limiting their functional mobility
during leg-extension exercise. The reason for recruiting young, healthy participants in the present
study was to reduce possible influences on the pressure response caused by an age related decline in
arterial wall elasticity (e.g.10). The participants mean ± SD age, height, weight and body mass index
(BMI) were 24.8 ± 3.9 years, 181.4 ± 5.7 cm, 79.7 ± 9.6 kg and 24.3 ± 3.2 kg·m2, respectively. The
participants were instructed to refrain from coffee and meals at least three hours prior to testing and
avoid heavy training and alcohol 24 hours before reporting to the lab. Written informed consent was
obtained from all participants prior to the experiments.
Study design
The overall aim of the study was to examine the hemodynamic and cardiovascular responses of two
bouts of resistance exercise and to assess the effects of different exercise components of the resistance
exercise bout; the exercise load, volume (number of sets) and duration (number of repetitions). To
assess the component of volume, the responses between the first and fourth sets within each bout was
analyzed. To examine the effect of load the 4RM data was compared to the 4th rep of the 20RM
protocol and to examine the effect of duration (number of repetitions) the 4th rep was compared to the
20th rep of the 20RM protocol.
To study this, the subjects reported to the laboratory on three different occasions, and testing was
performed at the same hour of the day on each occasion. On day one, the participants were tested for
their bilateral leg extension one repetition maximum (1RM), four repetition maximum (4RM) and 20
repetition maximum (20RM) in a training apparatus. One week later, on test day two and three, the
subjects completed one bout that consisted of a high-load/few repetition protocol (four sets of 4RM)
and one bout of low load/many repetition protocol in a randomized manner. There were four minutes
of recovery between sets and at least 48 hours of recovery between exercise bouts.
5
Procedure, strength testing
Following 5 min. warm up on a stationary ergometer cycle (Lode Excalibur Sport, Groningen, the
Netherlands), strength testing were completed in a leg extension apparatus (Steens Physical, Ski,
Norway). Excessive hip movements were restricted using a strap across the hips fasted to the
apparatus. The strength tests were performed in a standardized order; first the 1RM, then the 4RM,
and finally the 20RM. Pauses between tests were 4-6 min. Only attempts that could be lifted
throughout the full range of motion while maintaining correct technique was approved. During this
session, the participants were extensively coached in the breathing and lifting technique to ensure
correct execution of the breathing pattern (no Valsalva maneuver) and that the subjects managed to lift
the required number of repetitions during the experiments.
Procedure 4RM and 20 RM exercise testing
The participants performed a standard warm-up for five minutes on a stationary ergometer cycle
before they completed either four sets of 4RM or four sets of 20RM of bilateral leg-extensions. The
leg-extensions were completed in a controlled and continuous manner without pauses between
repetitions, using 1 sec. for the lifting phase (extension) and 1 sec. for the lowering phase. The
movements were paced by a metronome (60 beats min-1). To control the effect of breathing on the
blood pressure responses (7), the leg-extensions were performed without breath holding (Valsalva
maneuver), that is with exhalation during the extension phase and inhalation during the flexion phase
of the movement. All hemodynamic and cardiovascular measurements was performed with the
participants sitting in the training apparatus. Resting systolic and diastolic blood pressure (SBP, DBP),
heart rate (HR), stroke volume (SV), cardiac output (CO), end-diastolic volume (EDV), ejection
fraction (EF), and systemic vascular resistance (SVR) were recorded 30-60 seconds prior to start of
each set of exercise and are reported as the mean of the combined 4RM and 20RM resting values.
Exercise values of these variables were measured at the last repetition of each set with the leg fully
extended. For the 20RM protocol, measurements were also completed at the 4th rep. Blood lactate
concentration was measured immediately prior to start of set 1 (rest) and 60 seconds following the last
6
repetition in set 4. Rating of perceived exertion (RPE) were assesed by a 0-10 point scale prior to
exercise and immediately following the last repetition of each set.
Instruments and measurements
The SBP and DBP (mmHg) were recorded “beat-to-beat” by a validated volume oscillometric method
(Finapres, Ohmeda 2300, Colorado, USA). This method provides finger-cuff measurements of
peripheral arterial blood pressure, similar to intra-arterial values both at rest and during exercise (11,12).
The relative level of the finger to the heart may affect the mean blood pressure value at the finger,
consequently the participants were instructed to hold their hands open and to keep the arms folded
across their chest in a fixed position and the finger-cuff at the heart level at all times, both at rest and
during exercise (12).
The HR (beats·min-1), SV (mL·beat-1), CO (L·min-1), EDV ( mL) and EF (%) were assessed beat-to-
beat by impedance cardiography (PhysioFlow Enduro, Manatec, Folschviller, France). The reliability
and accuracy of this system has been compared to the direct Fick method both at rest and during
moderate exercise. Mean difference between the two methods was 0.04 L·min-1 at rest and 0.29 L·
min-1 during moderate exercise (13). In addition, the PhysioFlow Enduro has been compared to the
direct Fick method during maximal incremental exercise testing, and the correlation coefficient of the
two techniques was 0.946, (p < 0.01) with an average difference of -2.78% (14). Collectively, these two
studies conclude that the PhysioFlow Enduro provide clinically acceptable assessments of the CO
during both rest, moderate exercise and progressive maximal exercise (13, 14). Lactate concentration (La,
mMol·L-1) in capillary whole blood were measured by a Lactate Pro LT-1710 apparatus (Arkray Inc.,
Kyoto, Japan). Systemic vascular resistance (SVR, dyn· s-1 ·cm-5) was calculated according to
following formulae: MAP/CO x 80.
7
Statistical analyses
The data were analyzed by the SPSS version 18.0. Within group differences for SBP and DBP were
analyzed with one-way repeated measures ANOVA and the Sidak post-hoc test when significant
differences between series were found. A paired samples t-test was used when comparing resting and
exercise values of HR, SV, CO, EDV, EF, SVR, RPE and La. The significance level was set at p <
0.05. All results are expressed as means ± standard deviations.
8
Results
Maximal strength, 4RM and 20 RM loadings
The participants bilateral leg-extension 1RM was 70.2 ± 9.8 kg (p < 0.001, compared to 4RM and
20RM loads). The 4RM and 20RM loads (kg) were 62.7 ± 8.7 and 33.8 ± 6.1 kgs respectively (p <
0.001). The 4RM and 20RM loads corresponded to 89 ± 3 and 48 ± 7 % of the subjects’ 1RM.
Blood pressure responses. Effect of different loadings and duration
Pre exercise (Rest 0) SBP and DBP values (sitting in the training apparatus) were 126 ± 14 and 73 ± 9
mmHg, respectively. Compared to the corresponding resting values, the SBP and DBP values
increased significantly following set 1, 2, 3 and 4 of both the 4RM (~90 % of 1RM) and the 20RM RT
(~50 % of 1RM), respectively, (all comparisons, p < 0.001; figure 1 and 2). For each of the four sets,
both systolic and diastolic blood pressure increased more following the 20RM loading protocol than
the 4RM loading (all comparisons, p < 0.001; Figure 1 and 2). In the four minutes resting period
between sets, SBP and DBP exercise values showed complete recovery to pre exercise levels (Rest 1,
2 and 3) following both 4RM and 20RM RT.
There were no significant differences for neither SBP nor DBP after the 4RM loading protocol
compared to the 4th rep of the 20RM loading protocol. Consequently, when the duration of exercise
was similar (8.1 ± 0.5 and 7.8 ± 0.6 sec., respectively) there was no effect of an increase in exercise
loading from 50 % of 1RM to 90 % of 1RM (table 1). Both SBP and DBP values following the 4th
rep of 20RM RT were significantly lower than the corresponding values following the 20th rep of the
20RM exercise bout (both; p < 0.001; Table 1).
Blood pressure responses. Effect of exercise volume.
For the 4RM loading protocol, there were no differences in blood pressure values between set 1-4.
Thus, there seems to be no additive effect of multiple sets (e.g. volume) on the blood pressure
response during 4RM resistance training. For the 20RM protocol, there were no significant
differences in blood pressure values between set 1- 3 during 20RM RT, but a significant difference
9
between the SBP of set 1 (mean 192 mmHg ± 36) and set 4 (mean 217 mmHg ± 36) (p < 0.01; Figure
1). Thus, for 20RM protocol, there seems to be an effect of total exercise volume on the blood
pressure response.
Mean Arterial Pressure (MAP)
MAP resting values was 92 ± 10 mmHg. Compared to rest, exercise MAP (average of four sets)
increased significantly to 127 ± 20 and 165 ± 24 mmHg following the 4RM and 20RM RT,
respectively (both, p < 0.001). 20RM exercise MAP was different from 4RM exercise MAP (p <
0.001).
SV, HR, CO, EDV, EF and SVR responses to 4RM and 20RM RT (Table 2)
Compared to rest, exercise SV following 4RM and 20RM RT increased moderately with about 20 %
and 30 %, respectively (both, p < 0.001), and the increase was significantly larger for the 20RM
loading protocol than the 4RM protocol (p < 0.05). The increases in SV were mainly the result of an
increased EDV both following the 4RM and 20RM loading protocols (compared to rest, both; p <
0.001), while the EF was unchanged from rest with either type of loading protocol. Together with a
higher HR following the 20RM compared to 4RM loading protocol (p < 0.001), resulted in about 30 %
higher CO following 20RM exercise compared to 4RM exercise (p < 0.001). When compared to
resting values, the SVR decreased about 25 and 20 % following the 4RM and 20RM exercise,
respectively (p < 0.001 and p < 0.01), but there were no differences between 4RM and 20RM exercise
values.
La and RPE responses to 4RM and 20RM RT (Table 2)
Compared to the resting values, La levels increased by 46 % following the 4RM exercise (p < 0.001),
while La levels increased by 117 % following the 20RM bout (p < 0.001). The 20RM post exercise
lactate levels were higher than 4RM post exercise levels (p < 0.001). Post exercise RPE following the
4RM exercise was close to “very hard” (7 on the RPE scale), and close to “very-very hard” (10 on the
RPE scale) following 20RM exercise (compared to rest, both; p < 0.001). The difference in post
exercise RPE between the 4RM and 20RM exercise bouts was significant (p < 0.001).
10
Discussion
Blood pressure responses
In the present study, we have examined the separate effects of exercise load (4RM and 20RM),
volume (number of sets) and duration (number of repetitions) on important hemodynamic and
cardiovascular parameters. We found that both exercise loadings increased the exercise blood pressure
significantly from rest, which is in accordance with previous studies (6,15). There was, however, a
distinct difference in the pressure-response between the two loading conditions. Compared to 4RM
RT, the systolic and diastolic blood pressure was significantly elevated for 20RM exercise. Since the
load in kgs was substantially less for 20RM RT compared to 4RM RT, this demonstrates that the
absolute load (kg) lifted, is not the prime determinant of the blood pressure response. Moreover, our
results contradict the assumption that when RT is performed with a load corresponding to 70 % of
1RM or below, the intensity is not high enough to produce maximum blood pressure reactions (5).
There was no difference in blood pressure response comparing the 4th repetition of the 20RM protocol
to the 4RM protocol, clearly showing that increases in the external load does not increase blood
pressure further, when the duration of exercise is kept similar (Table 1). However, when the 20RM
exercise was performed to exhaustion, the exercise lasted about 38 seconds and blood pressures were
significantly elevated compared to the 4th rep of 20RM exercise (duration 7.8 sec.). Consequently, the
blood pressure response during RT is more related to the overall time of stimulus (number of
repetitions) than the absolute resistance in kg. We have, however, only examined this during 4RM and
20RM resistance exercise, and the relationship between blood pressure, exercise duration and the
external load during resistance training, needs to be examined in more detail in future studies.
Our findings are also in contrast to arguments that one should increase the number of repetitions
performed in each set before increasing the external resistance (16). On the contrary, in order to control
blood pressure responses, one should rather shorten the duration of exercise by increasing the
resistance or weight lifted (i.e. a lower total number of repetitions). In relation to this, increasing the
volume of exercise by performing multiple sets of resistance exercise does not seem to have a
cumulative effect on the exercise blood pressure. Thus, it seems that several sets of exercise could be
11
used in regular training without an additive increase in exercise blood pressure, at least for 4RM RT.
This response may be different with shorter rest intervals, but this was not investigated in the present
study.
Since the classical work of MacDougall et al. (6) it is frequently cautioned (e.g17,18) that very high
blood pressure values can be reached when performing low rep/high load resistance training. In this
respect, referral to the study of MacDougall et al. (6) may not be entirely justified. In the latter study,
five male body-builders performed double leg-presses without (obvious) Valsalva maneuver at 90 %
of 1RM to voluntary exhaustion. This resulted in a mean systolic/diastolic blood pressure of 320/225
mmHg, but the body-builders lifted as many as 17 repetitions (exercise duration ~40-60 sec.) before
exhaustion, which does not fit well with a an exercise load of 90 % of 1RM. In comparison, the
participants in the present study managed to lift four repetitions at 89 % of 1RM.
Thus, with respect to exercise duration and repetition number, the exercise performed by the body
builders (17 reps to failure; in other words 17RM exercise) is comparable to the 20RM exercise
performed in the present study.
The impact of exercise duration on the pressure response, is in fact, elegantly demonstrated by
MacDougall et al. (6), showing that the blood pressure during 17RM leg press, increaseses repetition-
by-repetition. These findings have, however, attracted less focus than the extremely high blood
pressure values that were reported in the same study.
It is suggested the hemodynamic response during resistance training depend mainly on the degree of
voluntary effort or relative muscular workload (15,19). In this respect, RT with a load of 50 % of 1RM
(20RM) may be classified as “moderate intensity” and a load of 90 % of 1RM (4RM) as “high
intensity”. It may easily be assumed that moderate intensity RT require less voluntary effort than high
intensity RT, but when a load of 50 % of 1RM is lifted to voluntary exhaustion, the physiological
responses (the degree of effort) are far from moderate. In that respect, both heart rate, cardiac output,
lactate levels and subjective ratings of perceived exertion were substantially higher following 20RM
exercise compared to 4RM RT. RPE scorings show that 20RM exercise were rated close to maximal,
with a mean score of 9.2 on a 10 point scale, versus a score of 6.3 for 4RM RT. In fact, all our subjects
12
verbalized that they clearly preferred 4RM exercise to 20RM exercise. Hence, performing 20RM
training require a high voluntary effort to complete, and this may be the key to understand the
hemodynamic responses of “moderate intensity” resistance training.
Cardiovascular responses
Cardiac output is determined by the product of HR and SV, and the present study show that both 4RM
and 20RM RT significantly increased CO, and our results are comparable to data following leg-press
(20) or isokinetic leg-extensions (19). The maximal CO in the present study (~14 L min-1) is, however,
only about 50 % of the maximal CO reported during intense short-term endurance exercise (21). In the
latter study, exercise SV peaked at 140-150 mL beat-1, while exercise SV in the present study changed
very little, and reached exercise values of 90-100 mL beat-1. Thus, similar to previous studies (22) SV
contributed very little to the increases in CO, and the increased CO in the present study was mainly
caused by increases in the heart rate (Table 2). Since the mean arterial pressure (MAP) is the product
of the cardiac output and systemic vascular resistance (SVR), an increase in cardiac output will
concurrently increase the blood pressure. In the present study, the SVR during 20RM exercise were
similar to 4RM exercise, but since CO was about 30 % higher during 20RM exercise, this would
largely explain the difference in blood pressure between 4RM and 20RM exercise.
An increased afterload (systemic vascular resistance) and decreased venous return could explain why
some studies observe little change in SV following dynamic resistance training (e.g.19,22, present study).
This was, however, not the case in the present study as there was a significant decrease in SVR for
both RT conditions. The effect of resistance training on systemic vascular resistance is little
investigated, but our study clearly shows a decrease in the SVR of about 30 % following 4RM and
20RM exercise. Our measurement system allows for online inspection of SVR data, and during testing
we could observe a progressive decline in the SVR during repeated contractions. Following
termination of exercise, SVR very quickly recovered to resting values (data not shown). This would
imply that venous return and cardiac filling was not compromised during exercise, and this is
substantiated by the fact that compared to rest, exercise end-diastolic volume (EDV) increased both
following 4RM and 20RM RT. Thus, repeated forceful contraction of the leg muscles may provide a
13
powerful muscle pump that enhances venous return and ventricular filling, as suggested by
MacDougall et al. (6). Left ventricular ejection fraction (EF) did not change with either type of RT,
and this is in agreement with data following leg press exercise at 60-70 % of 1RM (23). Hence, we
assume the small changes in SV in the present study are mainly caused by the observed increases in
EDV. We have, however, not investigated how changes in contractility may affect cardiovascular
responses during RT, so this topic remains to be examined.
Conclusion
The present results suggest that low rep/high load resistance exercise results in significantly lower
blood pressure than high rep/low load resistance exercise when the lifting is performed to voluntary
exhaustion. It is possible that the elevated hemodynamic response to 20RM compared with 4RM
exercise might reflect the total duration of contractile activity and increased sympathetic drive. We
suggest that low rep/high load exercise is preferable to high rep/low load resistance exercise during
rehabilitation exercise. In addition, one should preferably increase resistance before increasing the
repetition number if management of blood pressure responses is of concern.
14
REFERENCES
1. Campos, CER, Luecke, TJ, Wendeln, HK, Toma, K, Hagerman, FC, Murray, TF et al. Muscular
adaptations in response to three different resistance-training regimens: specificity of repetition
maximum training zones. Eur J Appl Physiol 2002;88:50-60.
2. Crewther B, Cronin J, Keogh J. Possible Stimuli for Strength and Power Adaptation. Acute
Mechanical Responses. Sports Med 2005;35:967-89.
3. Pedersen BK, Saltin B. Evidence for prescribing exercise as therapy in chronic disease. Scand J
Med Sci Sports 2006;(Suppl 1):3-63.
4. deVos NJ, Singh NA, Ross DA, StavrinosTM, Orr R, Fiatarone Singh MA. Continuous
hemodynamic response to maximal dynamic strength testing in older adults. Arch Phys Med Rehabil
2008;89:343-50.
5. Bjarnason-Wehrens B, Mayer-Berger W, Meister ER, Baum K, Hambrecht R, Gielen S.
Recommendations for resistance exercise in cardiac rehabilitation. Recommendations of the German
Federation for Cardiovascular Prevention and Rehabilitation. Eur J Cardiovasc Prevent Rehabil 2004;
11:352-36.
6. MacDougall JD, Tuxen D, Sale DG, Moroz DE, Sutton JR. Arterial blood pressure response to
heavy resistance exercise. J Appl Physiol 1985;58(3):785-90.
7. Narloch JA, Brandstater ME. Influence of Breathing Technique on Arterial Blood Pressure During
Heavy Weight Lifting. Arch Phys Med Rehabil 1995;76:457-62.
15
8.Suetta C, Magnusson SP, Rosted A, Aagaard P, Jakobsen AK, Larsen LH et al. Resistance training
in the early postoperative phase reduces hospitalization and leads to muscle hypertrophy in elderly hip
surgery patients. A controlled, randomized Study. J Am Geriatr Soc 2004;52:2016-022.
9. Andersen LL, Magnusson SP, Nielsen M, Haleem J, Poulsen K, Aagaard P. Neuromuscular
Activation in Conventional Exercises: Implications for Rehabilitation Therapeutic Exercises and
Heavy Resistance. Phys Ther 2006;86:683-97.
10. Gates PE, Seals DR. Decline in large elastic artery compliance with age: a therapeutic target for
habitual exercise. Br J Sports Med 2006;40:897–99.
11. Hildebrandt W, Schiitze H, Stegemann J. On the reliability of the Penaz cuff during systemic and
local fingertip vasodilatation at rest and in exercise. Eur J Appl Physiol 1991;62:175-79.
12. Imholz BPM, Wieling W, Van Montfrans GA, Wesseling KH. Fifteen years’ experience with
finger arterial pressure monitoring:assessment of the technology. Cardiovasc Res 1998;38:605-16.
13. Charloux A, Lonsdorfer-Wolf E, Richard R, Lampert E, Oswald-Mammosser M, Mettauer B et al.
A new impedance cardiograph device for the non-invasive evaluation of cardiac output at rest and
during exercise: comparison with the "direct" Fick method. Eur J Appl Physiol. 2000;82(4):313-20.
14. Richard R, Lonsdorfer-Wolf E, Charloux A, Doutreleau S, Buchheit M, Oswald-Mammosser M et
al. Non-invasive cardiac output evaluation during a maximal progressive exercise test, using a new
impedance cardiograph device. Eur J Appl Physiol 2001;85:202-7.
15. Sale DG, Moroz DE, McKelvie RS, MacDougall JD, McCartney N. Comparison of blood pressure
responses to isokinetic and weight-lifting exercise. Eur J Appl Physiol 1993;67:115-20.
16
16. Wise FM, Patrick JM. Resistance exercise in cardiac rehabilitation. Clin Rehabil 2011;25: 1059-
65.
17. Kelley GA, Sharpe Kelley K. Progressive Resistance Exercise and Resting Blood Pressure: A
Meta-Analysis of Randomized Controlled Trials. Hypertension 2000;35:838-43.
18. Gielen S, Niebauer J, Hambrecht R. Exercise Training in Heart Failure. In: Cardiovascular
Prevention and Rehabilitation, Perk, J et al. eds., Springer Verlag London, 2007. p. 142-56.
19. Lamotte M, Chevaliera A, Jamon A, Brassine E, van de Borne Ph. Hemodynamic response of an
isokinetic testing and training session. Isokinetics Exerc Sci 2009;17:135-43.
20. Lentini AC, McKelvie RS, McCartney N, Tomlinson CW, MacDougall JD. Left ventricular
response in healthy young men during heavy-intensity weight-lifting exercise. J Appl Physiol 1993;
75:2703-710.
21. Helgerud J, Høydal J, Wang E, Karlsen T, Berg P, Bjerkaas M et al. Aerobic High-Intensity
Intervals Improve VO2max More Than Moderate Training. Med Sci Sports Exerc 2007;39(4):665-71.
22. Stebbins CL, Walser B, Jafarzadeh M. Cardiovascular responses to static and dynamic contraction
during comparable workloads in humans. Am J Physiol 2002;283:R568–R75.
23. Karlsdottir AE, Foster C, Porcari JP, Palmer-McLean K, White-Kube R, Backes RC.
Hemodynamic Responses During Aerobic and Resistance Exercise. J Cardiopulmon Rehabil 2002;22:
170-77.
17
TITLES OF TABLES
Table 1. Effect of exercise load and number of repetitions on blood pressure responses
during 4RM and 20RM exercise bouts
Table 2. Cardiovascular and physiological responses to 4RM and 20RM exercise bouts
TITLES OF FIGURES
Figure 1. Systolic blood pressure (SBP) during resting and at the end of the last contraction for each
4RM and 20RM set.
Figure 2. Diastolic blood pressure (DBP) during resting and at the end of the last contraction for each
4RM and 20RM set.
18
Table 1. Effect of exercise load and number of repetitions on blood pressure responses
during 4RM and 20RM exercise bouts
Time, sec
SBP, mmHg
DBP, mmHg
Resting values
n.a
126 ± 14
73 ± 9
4th rep – 20RM load
7.8 ± 0.6
154 ± 18***
91 ± 14***
4th rep –4 RM load
8.1 ± 0.5
154 ± 22***.†††
99 ± 18***,†††
20th rep – 20RM load
38.3 ± 2.8§§§
203 ± 33***,§§§
126 ± 19***,§§§
LEGEND TABLE 1
Resting values are means ± SD of recordings prior to 4RM and 20 RM trials. Time, SBP and DBP
data are means ± SD of four sets of exercise. n.a = non applicable. Time (sec) = time taken to
complete 4 and 20 repetitions, respectively. N = 13. *** different from Resting, p < 0.001. ††† 20th rep
20RM different from 4th rep 4RM, p < 0.001. §§§ 20th rep 20RM different from 4th rep 20RM, p <
0.001.
19
Table 2 Cardiovascular and physiological responses to 4RM and 20RM exercise bouts
Rest
4RM RT
20RM RT
SV (mL· beat-1)
74 ± 9
90 ± 11***
96 ± 14 ***, †
HR (beats·min-1)
75 ± 8
124 ± 14***
150 ± 13***, †††
CO (L ·min-1)
5.6 ± 0.7
10.8 ± 2.6***
13.9 ± 2.2 ***, ††
EDV (mL)
148 ± 21
177 ± 25***
185 ± 29***
EF (%)
52 ± 6.0
52 ± 8.2
51 ± 8.1
SVR (dyn· s-1 ·cm-5)
Lactate (mMol· L-1)
RPE (0-10)
1263 ± 196
1.3 ± 0.3
0.9 ± 0.8
980 ± 305 ***
2.8 ± 0.7***
6.3 ± 1.6 ***
955 ± 206 **
10.3 ±1.3***,†††
9.2 ± 0.8***,†††
LEGEND TABLE 2
Values are means ± SD. ***p < 0.001, **p < 0.01; Rest vs. Exercise. ††† p < 0.001, †† p < 0.01, † p < 0.05;
4RM vs. 20RM RT. N=13. Resting values are means of recordings prior to 4RM and 20 RM trials.
4RM and 20RM values are means of four sets of resistance exercise.
20
LEGEND FIGURE 1
Values are means ± SD. N = 13. Rest 0 values are baseline recordings prior to start of exercise, while
Rest 1-3 are resting values between sets of exercise (all resting values are means of 4RM and 20RM
recordings). *** p < 0.001; Rest 0, 1, 2 and 3 compared to Set 1, 2, 3 and 4 of 20RM exercise,
respectively. §§§ p < 0.001; Rest 0, 1, 2 and 3 compared to Set 1, 2, 3 and 4 of 4RM exercise,
respectively. ††† p < 0.001; Set 1-4 of 4RM exercise compared to corresponding set of 20RM exercise.
21
LEGEND FIGURE 2
Values are means ± SD. N = 13. Rest 0 values is baseline recordings prior to start of exercise, while
Rest 1-3 are resting values between sets of exercise (all resting values are means of 4RM and 20RM
recordings). ** p < 0.01, *** p < 0.001; Rest 0, 1, 2 and 3 compared to Set 1, 2, 3 and 4 of 20RM
exercise, respectively. §§§ p < 0.001; Rest 0, 1, 2 and 3 compared to Set 1, 2, 3 and 4 of 4RM exercise,
respectively. †† p < 0.01, ††† p < 0.001; Set 1-4 of 4RM exercise compared to corresponding set of
20RM exercise.
