Salwa B. El-Sobkey, and Hazzaa M. Al-Hazzaa*
1Department of Rehabilitation Sciences, College of Applied Medical Sciences, King Saud University, Saudi Arabia
2Pediatric Exercise Physiology Research Laboratory, College of Education, King Saud University, Saudi Arabia
Received: 06 September, 2014; Accepted: 25 October, 2014; Published: 27 October, 2014
Hazzaa M. Al-Hazzaa, PhD, FACSM, FECSS, Professor and Director, Pediatric Exercise Physiology Research Laboratory, College of Education, King Saud University, P. O. Box 2458, Riyadh 11451, Saudi Arabia, Email:
El-Sobkey SB, Al-Hazzaa HM (2014) Heart Rate and Perceptual Responses to Graded Leg and Arm Ergometry in Healthy College-Aged Saudis: Effects of Gender and Exercise Mode. J Nov Physiother Phys Rehabil 1(2): 059-066. DOI: 10.17352/2455-5487.000011
© 2014 El-Sobkey SB, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Arm exercise; Gender; Heart rate; Leg exercise; Perceived exertion; Saudi Arabia
Objective: To assess gender differences in heart rate (HR) and perceptual responses during leg versus arm ergometry among healthy college-aged Saudis.
Methods: Forty healthy college-age Saudis (20 males) performed, in a random cross-over design, two maximal graded exercise leg (LE) and arm ergometry (AE). HR was continuously monitored/recorded during resting and throughout exercise period. Participants rated their perceived exertion (RPE), using Borg scale, at the end of each two-minute stage. Lactate from capillary blood was measured before and one minute after each test.
Results: Females had significantly (p<0.01) higher resting HR and lower resting blood pressure than males. There were significant (p<0.05) gender by exercise mode interactions in most of the parameters. Peak HR (bpm) was significantly (p<0.001) higher during LE than AE in males (181±12 vs 172±21) and females (176±9 vs 162±16), without significant gender difference. Males had significantly (p<0.015) higher values than females in absolute peak work load (WL) and exercise time and lower HR and RPE at absolute sub-maximal exercise. Peak arm/leg WL ratio was significantly (p=0.006) higher among females (54.6±12.7%) compared with males (45.1±6.9%). Gender differences in HR and RPE at 50% of peak WL were significant at LE.
Conclusions: Significant hemodynamic, perceptual and performance differences existed between Saudi males and females in response to LE and AE. This has important implications to exercise testing, prescription and rehabilitation.
Both leg and arm ergometers are commonly used as a mode of exercise testing. Leg ergometer which is widely used in clinical practice utilizes larger muscle group. However, arm ergometer though uses smaller muscle mass is an important testing modality especially in patients with reduced capacity to use their legs, as in those inflected with spinal cord injuries or peripheral artery diseases [1-4]. It is well recognized that physiological differences exist between upper and lower body sub-maximal and maximal exercise. In general, arm-cranking exercise elicits a maximal oxygen uptake (VO2 max) corresponding to approximately 70% of the value reached during leg exercise . However, at equal power output, arm exercise elicits greater cardiovascular, metabolic and perceptual responses compared to leg exercise [4,6,7].
The measurement of subjective feelings of exertion by means of 15 point category scale was first reported by Borg . Since then, rating of perceived exertion (RPE) had been applied in numerous studies involving healthy adults and cardiac patients [9,10]. The American College of Sports Medicine recommends basing exercise intensity on a power output or velocity, heart rate (HR) and /or RPE associated with target oxygen uptake . In addition, there was a strong association between RPE and blood lactate, regardless of exercise mode or training status .
Gender-related RPE showed interesting and sometimes conflicting findings. Although heart rate responses were higher for females compared to males, no difference in RPE between groups of men and women of low and high athletic experience during different sub-maximal exercise intensities . Moreover, Robertson et al. (2000) found no difference between genders when comparisons were made at relative oxygen uptake and heart rate reference criteria at exercise intensity between 70 and 90% of mode-specific maximal values . In contrast, O’Connor, et al reported greater RPE in females compared to males during arm exercise at the same absolute power output . In addition, when gender-specific RPE responses were studied during treadmill, cycle ergometer and ski machine, heart rate was higher in female than male participants for each of the three modes of exercise .
Previous local research indicates that only one study had been reported on the physiological responses of upper and lower body exercise testing and was involved adolescent males . In addition, a graded leg ergometry testing in untrained Saudi males 20-50 year-old elicited lower maximal heart rate and maximal oxygen uptake than aged- predicted maximal values . Saudi females were also shown to be much less active than males and have fewer opportunities for engaging in leisure sports compared with males [18-20]. The research hypothesis was that Saudi female’s responses to arm and leg exercise may be significantly different to that of the males. All these considerations make it necessary to examine the gender-related perceptual, heart rate and performance differences in response to upper and lower body exercise testing in a group of Saudi young adults. Therefore, the present research was conducted to assess the gender differences in heart rate, perceptual and performance responses to leg versus arm ergometry among untrained yet healthy college-aged Saudi males and females.
Forty volunteers (20 females and 20 males) University-students from Riyadh, Saudi Arabia were recruited for this study through bulletin board announcement. The selection criteria included Saudi nationals, non-smokers, non-pregnant, non-athletes or not engaged in regular exercise program, free from any cardiovascular, pulmonary, metabolic or musculoskeletal problems and with age range from 18 to 24 years. Body weight and height was measured using Seca scale (Germany). Body mass index (BMI) was calculated by dividing weight in kg over squared height in meter.
The study protocol and procedures were approved by the Boards of Research Center at the College of Applied Medical Sciences, King Saud University. The study protocol and procedures were in accordance with international ethical guidelines. In addition, each participant signed a consent form after reading the aim, procedures and possible risks and benefits of taking part in this study. Before tested, each participant was screened for major risk factors to role out any contraindication to maximal exercise testing, using a modified Physical Activity Readiness Questionnaire (PAR-Q) form (1). Resting HR (using Exercentry, USA) and blood pressure (using a sphygmomanometer) were also measured while seated. Then, each participant performed, in a random cross-over design, two graded exercise tests (leg and arm ergometry) to maximal effort in separate sessions. The tests were conducted two hours after a meal in a comfortable laboratory environment while separated with at least one day.
Leg and arm ergometry testing
The leg exercise test was conducted using mechanical cycle ergometer (Monark- Sweden) in a comfortable laboratory environment (22 Ċ). After seat height adjustment, the participant started pedaling at 60 rpm staring at 30 watts for 2 minutes. Thereafter, the power output increased 15 watts every 2 minutes until exhaustion. The arm exercise test was conducted using Monark Rehab Trainer 814E (Sweden) that was secured to a table. The seat was hydraulically adjusted to the participant’s comfortable position, so that the acromion process was horizontal with the center of the axle connected to the hand grip. The arm ergometry test was a continuous progressive protocol started with zero watt for the first 2 minutes and the work load was increased the by 10 watts every 2 minutes until exhaustion or the subject was unable to maintain a cranking rate of 60 rpm.
HR and RPE measurements
HR was continuously monitored and recorded during resting and throughout the exercise period using heart rate measuring equipment (Exercentry, USA). RPE was assessed using Borg 15 point scale (6-20), which was mounted on a stand with clear and large letters in front of the participant.7 Participants were asked to rate their perceived exertions at the end of each two-minute stage. In addition, blood lactate was measured by Accutrend lactate analyzer (Roche, Germany) before and one minute after each exercise test, using capillary blood sample from finger brick.
Data were analyzed using SPSS, version 20 (IBM). Descriptive statistics were presented as means, standard deviations. Differences in anthropometric and physiological measurements between males and females were tested using independent t-test. In addition, repeated measure 2-way ANOVA was performed to test the effect of exercise mode (arm versus leg ergometry) and gender (males versus females) on peak and submaximal physiological, perceptual and performance variables. In addition, the differences in HR and RPE responses at 50% of maximal work load values were tested using independent t-tests. Finally, multiple regression analyses, with stepwise procedures, were performed to predict maximal leg work load from gender and submaximal leg exercise variables (HR and RPE at minute 8 as well as predicting maximal leg work load from gender, maximal arm work load and submaximal arm exercise variables (HR and RPE at minute 8). Durbin-Watson coefficients to indicate independence of residuals were satisfactory (ranged from 1.236 to 1.333). The level of significance was set at a p value of 0.05 or less.
Table 1 shows the anthropometric and resting physiological parameters of the participants. Females participants in the study were significantly younger (p = 0.025), shorter (p < 0.001) and weigh less (p = 0.005) than the males. There was no significant difference between males and females in BMI. However, the proportion of females with BMI > 25 kg/m2 was lower (25%) than that of males (45%). Females had significantly higher resting HR (p = 0.009) and lower resting blood pressure (p < 0.001) than males. No significant difference was exhibited between males and females in resting blood lactate.
The results of the repeated measure ANOVA for the effects of exercise mode and gender on physiological, perceptual and performance variables are shown in table 2. There were significant (p < 0.05) gender by exercise mode interactions in the majority of the examined parameters. Peak HR (bpm) was significantly (p < 0.001) higher during leg exercise than arm ergometry for both males (181 ± 12 versus 171 ± 21) and females (176 ± 9 versus 162 ± 16), without significant (p = 0.083) gender difference.
Males had significantly (p< 0.015) higher values than females in absolute peak work load (watts) and time (min) to exhaustion and lower HR and RPE at absolute sub-maximal but not at maximal exercise. The ratio of peak work load of arm relative to that of leg was significantly (p = 0.006) higher among females (53.8%) than that found in males (44.9%). Work load at minute eight of exercise test represented an absolute work rate of 30 and 75 watts for arm and leg testing, respectively. However, work load at 50% of maximal work load is relative work load for both sexes.
Figures 1 and 2 exhibit HR and RPE responses to graded leg and arm exercise testing in each of Saudi males and females. Only exercise periods (min) where all subjects were able to have achieved are included in these figures. Tests of between subject effects for gender differences in HR at min 2 through 12 were significant (p < 0.001). However, tests of between subject effects of gender differences in RPE showed significance at only min 6 (p = 0.026), min 8 (p = 0.001) and min 10 (p = 0.002).