Heart Rate and Ratings of Perceived Exertion during Treadmill and Elliptical Exercise Training

Energy expenditure, oxygen consumption, and heart rate while exercising on seven different indoor cardio machines at maximum and self-selected submaximal intensity

Objective

One of the main objectives of practicing indoor cardiovascular exercise is to maximize caloric expenditure. This study aimed to compare energy expenditure (EE), oxygen consumption (VO2), and heart rate (HR) recorded in middle-aged adults while exercising on seven different indoor cardiovascular machines at self-selected maximal and submaximal intensity.

Method

Thirty recreational-active adult males (Age: 41.69 ± 4.64) performed 12-min bouts at RPE (Rate of perceived exertion) 17 and maximum intensity (MAX INT) on the following indoor cardio machines: Recumbent bike (r_BIKE), upright bike (u-BIKE), spin bike (s-BIKE), rowing machine (ROW), elliptical trainer (ELLIP), stair climber (STAIR), and treadmill (TMILL). Heart rate (HR) and oxygen consumption (VO2) were measured during exercise, whereas EE (energy expenditure) was calculated indirectly.

Results

Overall, TMILL induced the highest levels of EE, VO2, and HR, followed by STAIR, ELLIP, s_BIKE, u_BIKE, ROW, and r_BIKE. RPE was reliable across exercise modalities (r_BIKE, u-BIKE, s-BIKE, ROW, ELLIP, STAIR, and TMILL) and intensities (RPE 17 and MAX INT) for EE, HR, and VO2 measurements.

Conclusion

To maximize EE while performing indoor cardiovascular exercise for recreational active middle-aged male participants, the TMILL is the best option, followed by the STAIR and the ELLIP. The least recommended options are, respectively, s_BIKE, u_BIKE, ROW, and r_BIKE. Beyond caloric expenditure considerations, promoting exercises that participants genuinely enjoy can enhance adherence, fostering sustained health benefits. Furthermore, RPE is a reliable tool for assessing EE, VO2, and HR across different exercise modalities and intensities.

Physiological and Metabolic Responses to Exercise on Treadmill, Elliptical Trainer, and Stepper: Practical Implications for Training

Elliptical trainers and steppers are proposed as useful exercise modalities in the rehabilitation of injured runners due to the reduced stress on muscles and joints when compared to running. This study compared the physiological responses to submaximal running (treadmill) with exercise on the elliptical trainer and stepper devices at three submaximal but identical workloads. Authors had 18 trained runners (male/female: N = 9/9, age: mean ± SD = 23 ± 3 years) complete randomized maximal oxygen consumption tests on all three modalities. Submaximal tests of 3 min were performed at 60%, 70%, and 80% of peak workload individually established for each modality. Breath-by-breath oxygen consumption, heart rate, fuel utilization, and energy expenditure were determined. The value of maximal oxygen consumption was not different between treadmill, elliptical, and stepper (49.3 ± 5.3, 48.0 ± 6.6, and 46.7 ± 6.2 ml·min-1·kg-1, respectively). Both physiological measures (oxygen consumption and heart rate) as well as carbohydrate and fat oxidation differed significantly between the different exercise intensities (60%, 70%, and 80%) but did not differ between the treadmill, elliptical trainer, and stepper. Therefore, the elliptical trainer and stepper are suitable substitutes for running during periods when a reduced running load is required, such as during rehabilitation from running-induced injury.

Effects of Impact Versus Non-impact Cardiovascular Machines in Individuals between Age 50 and 80 Years

Older adults are at increased risk of injury when initiating exercise due to inactivity, functional limitation, illness, or fall risk. We studied a novel non-impact cardio unit in an effort to determine whether there were differences in physiologic, functional, and strength benefits compared to a treadmill (TM), while producing less stress on the knee and lessening the risk of fall and injury. Utilizing a prospective, randomized, non-blinded, cohort design, individuals aged 50–80 years were recruited and enrolled in a 16-week exercise program. Subjects were randomly allocated to either exercise on the Cybex arc trainer or on a TM. Participants exercised for 120 min per week. Resistance was adjusted to achieve a target RPE in each group. Functional, strength, and physiologic markers were analyzed through balance testing, ten – repetition max leg press, body composition analysis, and lipid panel results. Overall health-related quality of life was also measured. There was a significant improvement in triglyceride and very low density lipoprotein levels from baseline to exit within the arc trainer group. An equal and significant increase in strength capacity was observed in both the arc trainer and TM groups, as were feelings of increased energy, improved emotional well-being, and decreased fatigue. Leg strength increased, percentage of body fat decreased, and balance improved following use of either an arc trainer or a TM in a study population of 58 participants over a 16-week period. This study demonstrated that positive change occurs, physiologically and psychologically when an arc trainer or TM is utilized. Given the similar benefits seen in this study, use of a non-impact modality such as the arc trainer may be a better alternative in the older population.

Development of a Metabolic Equation for Elliptical Crosstrainer Exercise

The purpose of this study was to develop an accurate metabolic prediction equation for elliptical crosstrainer (ECT) exercise. Male and female ( n = 40) subjects ( M ± SD, age: 30 ± 7 yr.; height: 173 ± 11 cm; weight: 72.3 ± 13.8 kg; body composition: 18.3 ± 6.9%) completed two randomized testing sessions. Steady-state oxygen uptake (VO2) was measured, while subjects exercised on the ECT at nine separate workloads each testing session. Multiple regression analysis to predict steady-state VO2 from ECT resistance, ECT cadence, and subjects' body mass resulted in the following model ( R2 = .783): Steady-state VO2 = 3.5 + 0.15(Cadence) + 1.22 (Resistance) − 0.11 (Weight). Both the standard error of the estimate ( SEE) and total error ( TE) for the prediction of steady-state VO2 under all ECT workload conditions combined were 2.8 mL/kg/min. The SEE and TE values are similar to those previously reported in the literature regarding the accuracy of metabolic equations for other exercise modalities. These findings support the use of the equation developed in the present study to predict steady-state VO2 for ECT exercise.

Content Validation of a Catalog of Exercises for Judo

This study aimed to assess the content validity of a catalog of 76 judo exercises. Two groups of raters comprising 16 judo experts evaluated the following content validity indicators: Clarity of Language, Practical Pertinence, Theoretical Relevance, and the Dimension of each exercise. The results confirmed the content validity of the judo training catalog with indicators showing scores greater than 0.80. These findings suggest that all 76 judo exercises are pertinent, representative of judo training and understandable for judo coaches. Thus, this catalog of judo exercises may help judo coaches in the selection and recording of exercises.

Validity of arm-leg elliptical ergometer for VO2max analysis

Maximal oxygen consumption ((Equation is included in full-text article.)) can be determined through multiple exercise modalities intended to elicit an individual's maximal aerobic exertion. Uphill treadmill running is considered the best modality for measuring (Equation is included in full-text article.). Previous studies have examined correlations between treadmill and elliptical ergometer tests as well as the cycle ergometer, but none of the studies use an arm-leg elliptical ergometer (ALE). The purpose of this study was to develop an ALE (Equation is included in full-text article.)testing protocol and determine whether ALE produces valid (Equation is included in full-text article.)values as compared with the treadmill. Twelve undergraduate students (mean age: 20.8 years) completed 2 (Equation is included in full-text article.)tests, 1 on a treadmill and 1 on ALE. (Equation is included in full-text article.)correlation between ALE and treadmill was examined, and paired t-tests were run for (Equation is included in full-text article.)and maximum heart rate (HRmax). A strong positive correlation was found between ALE and treadmill (Equation is included in full-text article.)values (r = 0.84; p < 0.001). There were no differences between (Equation is included in full-text article.)values; however, HRmax values were higher on the treadmill than ALE (p = 0.003). Although future research is needed to examine the observed differences in HRmax between the 2 testing modalities and gender differences in muscle recruitment patterns, the results of this study suggest that ALE is a valid modality for (Equation is included in full-text article.)testing. This will be particularly valuable as a clinical tool to assess (Equation is included in full-text article.)in populations requiring low-impact exercise.

THE EFFECTS OF PEDAL RATES ON PEDAL REACTION FORCES DURING ELLIPTICAL EXERCISE

Despite the growing popularity in recent years of elliptical exercise (EE), little is known regarding the loadings applied to the body during EE. Since overloading to the body may lead to early fatigue of the muscles and increase the incidence of overuse injuries, such information is necessary for safe use of the elliptical trainer (ET) as a fitness tool. The current study aimed to determine the typical patterns and loading rates of the measured pedal reaction forces (PRF), and to quantify their differences from those during level walking, and the effects of pedaling rate. Fifteen male adults performed level walking and EE while 3D marker data, right PRFs and ground reaction forces (GRF) were measured. The parameters of the ET were set for two different pedal rates: 50 rpm and 70 rpm. For each pedal rate, the parameters were set to match the variables measured during level walking, with a mean step length of 55% leg length and no workload. During early stance the vertical PRF was smaller than the GRF, while the medial and posterior PRF were greater. PRFs also occurred during swing. Loading rates around heelstrike during EE were all smaller than those during walking. The medial, anterior and posterior PRF, as well as the medial and vertial loading rates increased with increasing pedal rates. The basic force patterns of EE and the effects of pedal rate were established in order to determine the true potential for such instrumentation in locomotion analysis. The results will be helpful for future related studies.

Validation of adult omni perceived exertion scales for elliptical ergometry

This investigation examined the validity of newly developed Adult OMNI Elliptical Ergometer Ratings of Perceived Exertion Scales. 60 men and women performed a graded exercise test on an elliptical ergometer. Oxygen consumption (VO2), heart rate (HR), and ratings of perceived exertion were recorded at each stage from the Borg 15 Category scale and two different OMNI scales. One scale employed an elliptical ergometer format of the OMNI Picture System of Perceived Exertion. The second scale modified verbal, numerical, and pictorial descriptors at the low end of the response range. Concurrent and construct validity were established by the positive relation between ratings of perceived exertion from each OMNI scale with VO2, HR, and Borg scale ratings of perceived exertion (men, r = .94-.97; women, r = .93-.98). Validity was established for both OMNI scales, indicating either metric can be used to estimate ratings of perceived exertion during partial weight-bearing exercise.

Use of an elliptical machine for improving functional walking capacity in individuals with chronic stroke: a case series

BACKGROUND AND PURPOSE

Decreased functional walking capacity is a common consequence of stroke. Identifying practical and cost-effective methods to improve walking in individuals with stroke is an important goal of rehabilitation professionals.

PARTICIPANTS

Participants were 3 men with chronic (>6 month) stroke, who could walk on level surfaces either without an assistive device or with a single-point cane.

INTERVENTION

Participants trained 2 to 3 times per week for 8 weeks, using an elliptical machine. The training target was 20 minutes of uninterrupted training, while maintaining predetermined parameters of heart rate and perceived exertion.

OUTCOMES

Outcome measures assessed before and after training included habitual and fast gait speed, 6-minute walk test (6MWT), Timed "Up & Go" test, and Berg Balance Scale. Following training there was no change in walking speed. There was no change in 6MWT performance for participants 1 and 2. While participant 3 showed a 25% improvement in 6MWT, this change did not meet the minimal detectable change for walking speed in individuals with stroke. All participants demonstrated improved Berg Balance Scale performance (9%-28%), with participant 1 exceeding the minimal detectable change in this measure. Timed Up & Go test performance improved by 5% to 15% in all participants.

DISCUSSION

Elliptical training appears to be a safe and feasible training alternative for ambulatory individuals with chronic stroke. Training 2 to 3 days per week resulted in no improvements in walking speed; however, participants did demonstrate variable improvements in endurance, balance, and functional mobility. It is possible that a higher training frequency and/or training speed are required to influence walking performance in individuals who are ambulatory. Equipment design, principles of exercise prescription, and participant characteristics should be considered when selecting elliptical training as an intervention.

A comparison of physiologic and physical discomfort responses between exercise modalities

To determine differences in physiologic responses and perceived discomfort during maximal and submaximal exercise with 2 common exercise modalities, the elliptical cross-trainer (ECT) and the arc trainer (ARC) were used, which undergoes an excursion of motion using an arc pathway. Eighteen subjects (10 male and 8 female; age = 24.7 +/- 2.6 yr, height = 172.2 +/- 10.3 cm, mass = 69.8 +/- 14.9 kg, %fat = 22.5 +/- 8.1%; mean +/- SD) performed maximal exercise protocols on a treadmill (TML), the ECT, and ARC. Subjects also performed 3 10-minute submaximal exercise bouts on the ECT and ARC at 55%, 65%, and 75% of TML maximal oxygen uptake (VO2max) in which heart rate (HR), VO2, ventilation, respiratory exchange ratio, and hip, knee, and low-back discomfort were monitored. All testing on the ECT and ARC were performed in a counterbalanced order. The VO2max was greater during TML exercise compared with ECT (p = 0.007) but similar to the ARC. Both ECT and ARC elicited lower maximal HR values compared with maximal TML exercise (p = 0.0001). No difference was observed between ECT and ARC for VO2 during the submaximal exercise bouts (p > 0.05). However, HR was greater during submaximal ECT exercise (p < 0.0001). Perception of discomfort was not different between ECT and ARC for knees (p > 0.05) and lower back (p > 0.05) but different for the hips (p = 0.02). Similar VO2max values were observed with ARC and TML modalities. Greater perceptions of discomfort were observed with ECT compared with ARC at similar submaximal exercise intensities, suggesting individuals with, or at risk for, lower-extremity joint pathology may benefit from exercise with modalities other than the ECT.

Using Electromyography to Detect the Weightings of the Local Muscle Factors to the Increase of Perceived Exertion During Stepping Exercise

Rate of perceived exertion (RPE) is a clinically convenient indicator for monitoring exercise intensity in cardiopulmonary rehabilitation. It might not be sensitive enough for clinicians to determine the patients' physiological status because its association with the cardiovascular system and local muscle factors is unknown. This study used the electromyographic sensor to detect the local muscle fatigue and stabilization of patella, and analyzed the relationship between various local muscle and cardiovascular factors and the increase of RPE during stepping exercise, a common exercise program provided in cardiopulmonary rehabilitation. Ten healthy adults (4 males and 6 females) participated in this study. Each subject used their right bare foot to step up onto a 23-cm-high step at a constant speed until the RPE score reached 20. The RPE, heart rate (HR), and surface EMG of the rectus femoris (RF), vastus medialis, and vastus lateralis were recorded at 1-minute intervals during the stepping exercise. The generalized estimating equations (GEE) analysis indicated that the increase in RPE significantly correlated with the increase in HR, and decrease in median frequency (MF) of the EMG power spectrum of the RF. Experimental results suggest that the increase in RPE during stepping exercise was influenced by the cardiovascular status, localized muscle fatigue in the lower extremities. The weighting of the local muscle factors was more than half of the weighting of the cardiovascular factor.

Joint Loading in the Lower Extremities during Elliptical Exercise

PURPOSE

To determine the joint loading during elliptical exercise (EE) by a detailed three-dimensional dynamic analysis, and to compare the results with those during level walking.

METHODS

Fifteen male adults performed level walking and EE while 3D kinematic data, right pedal reaction forces (PRF), and ground reaction forces (GRF) were measured. Pedal rate (cadence) and step length during EE without workload were set according to those measured during level walking for each subject. The motion of the body's center of mass, lower-limb-joint angles and moments were obtained.

RESULTS

Pedal rates and step lengths were 52.20 rpm (SD=2.34) and 50.56 cm (SD=2.14), respectively. During early stance the vertical PRF was smaller than the GRF, and the medial and posterior shear components were greater. PRF also occurred during swing. Loading rates around heelstrike during EE were all smaller than those during walking. During EE, the peak flexion angles of the hip, knee and ankle were greater. Peak hip flexor and knee extensor moments were also greater, whereas peak ankle plantarflexor moments and all abductor moments were smaller.

CONCLUSIONS

Different lower-limb kinematics and kinetics were found between EE and level walking. Smaller vertical PRF and loading rates during EE were achieved at the expense of greater hip flexor and knee extensor moments. Use of the elliptical trainer for athletic and rehabilitative training would have to consider users' joint function and muscle strength, especially at the knee, to avoid injuries.