Exercise testing: Improving performance with a ramped Bruce protocol

doi:10.1016/S0002-8703(99)70067-0

American Heart Journal

Volume 138, Issue 6, December 1999, Pages 1033-1037

https://doi.org/10.1016/S0002-8703(99)70067-0 Get rights and content

Abstract

Background The standard Bruce protocol was compared with a ramped Bruce protocol in stress testing of a general population of patients. Methods We examined hemodynamic responses, test duration, and patient comfort with each exercise protocol. Twenty-three patients completed the study, 14 men and 9 women with a mean age of 51 ± 12 years. Each patient completed the 2 treadmill protocols in a random manner. Results Mean peak heart rate, systolic blood pressure, and rating of perceived exertion according to the revised Borg scale were equivalent in both protocols, measuring 157 ± 15 beats/min, 170 ± 22 mm Hg, and 8 ± 1 for the Bruce and 158 ± 17 beats/min, 175 ± 20 mm Hg, and 8 ± 1 for the ramp protocol (P = NS). Duration of test and metabolic equivalents (METs) were greater with the ramp than with the Bruce protocol. For the Bruce duration and METs were 8:25 ± 3:00 min and 9.6 ± 3.1, and for the ramp 10:01 ± 2:32 min and 11.4 ± 2.7 (P < .0001 for both). Subjective rating of difficulty was assessed on a scale of 1 to 5, 1 being the most difficult and 5 being the easiest. Rating for the Bruce protocol was 2.5 ± 0.9 and for the ramp 4.1 ± 0.9 (P < .0001). Conclusion We propose that a ramped modification of the Bruce protocol achieves equivalent hemodynamic goals but with better duration. Patients preferred the ramp with respect to comfort, and exercise data can be correlated easily with standard protocols. (Am Heart J 1999;138:1033-7.)

Section snippets

Methods

After approval by the institutional review board for human study protocols, subjects were recruited randomly from patients undergoing treadmill stress testing with or without a nuclear component at the noninvasive cardiology division of a large city hospital. The patients had been instructed to continue their usual medications and had been asked to abstain from food, coffee, and cigarettes for at least 3 hours before the study.

Thirty patients were initially enrolled in the study. After informed

Results

The hemodynamic and observational data for both stress tests are presented in Table III.

. Hemodynamic and observational data (mean ± SD) for Bruce and ramped Bruce protocols

Value	Bruce	Ramped Bruce	P value (if <.05)
Resting heart rate (beats/min)	71 ± 14	72 ± 13	—
Resting systolic blood pressure (mm Hg)	131 ± 15	131 ± 14	—
Resting diastolic blood pressure (mm Hg)	79 ± 7	76 ± 8	—
Peak heart rate (beats/min)	157 ± 15	158 ± 17	—
Peak systolic blood pressure (mm Hg)	170 ± 22	175 ± 20	—
Peak diastolic blood pressure (mm Hg)

Discussion

This study was undertaken to compare, in a general population undergoing exercise stress testing, a standard and time-honored treadmill protocol, the Bruce, with a ramped form of the same protocol. Myers et al.¹¹ demonstrated that although there is hemodynamic comparability among protocols, there are marked variations in maximal oxygen uptake and the dynamics of gas exchange in conventional protocols compared with ramp protocols. Their study showed the ratio of oxygen uptake to work rate is

References (22)

ML Pollock et al.
A comparative analysis of four protocols for maximal treadmill stress testing
Am Heart J
(1976)
J Myers et al.
Comparison of the ramp versus standard exercise protocols
J Am Coll Cardiol
(1991)
SV Aksut et al.
Comparison of left ventricular performance in healthy young women and men during exercise
J Nucl Cardiol
(1996)
K Bhadha et al.
Comparison of the Bruce and ramp protocols in the assessment of left ventricular performance during exercise in healthy women
Am J Cardiol
(1995)
MWJ Webster et al.
Exercise testing in angina pectoris: the importance of protocol design in clinical trials
Am Heart J
(1989)
J Myers et al.
Individualized ramp treadmill: observations on a new protocol
Chest
(1992)
PH Brubaker et al.
Identification of the anaerobic threshold using double product in patients with coronary artery disease
Am J Cardiol
(1997)
RA Bruce
Exercise testing of patients with coronary artery disease
Ann Clin Res
(1971)
B Balke et al.
An experimental study of physical fitness of air force personnel
US Armed Forces Med J
(1959)
PO Astrand et al.
Textbook of work physiology

MH Ellestad et al.

Maximal treadmill stress testing for cardiovascular evaluation

Circulation

(1969)

Cited by (54)

The Intrarater and Interrater Reliability of Measures Derived from Cardiopulmonary Exercise Testing in Patients with Abdominal Aortic Aneurysms
2019, Annals of Vascular Surgery
Citation Excerpt :
To minimize any confounding factors, testing was carried out at the same time each day and in the same environment at a maximum of one week apart. The Modified Bruce protocol consists of three-minute incremental minute stages12 commencing with walking at 1.7 miles per hour (mph) on a 0% gradient and progressing to an upper stage of walking at 5.5 mph on a 20% gradient. The cycle protocol was based on the following stages:13
Patients with abdominal aortic aneurysms (AAAs) often have low exercise tolerance due to comorbidities and advanced age. Cardiopulmonary exercise testing (CPET) is predictive of postoperative morbidity and mortality in patients with AAA. We aimed to assess the intrarater and interrater reliability of both treadmill-based and cycle ergometer–based CPET variables.
Patients with an AAA (>3.5 cm) were randomized to a treadmill or bike CPET. Patients were asked to perform two separate CPETs seven days apart after a familiarization protocol. All CPETs were carried out using a ramp cycle or modified Bruce treadmill protocol with breath-by-breath gas analysis.
Twenty-two male and 2 female patients, aged 73.6 ± 6.0 years, completed the study. Intrarater analysis (intraclass correlation coefficients) demonstrated high reliability on both the treadmill and bike for ventilatory anaerobic threshold (r = 0.834 and r = 0.975, respectively). All other CPET variables demonstrated high intrarater reliability on both modalities, bar the highest point for the ventilatory slope of oxygen (VE/VO₂) on the treadmill (substantial agreement r = 0.755). Furthermore, interrater reliability demonstrated high agreement for ventilatory anaerobic threshold on both the treadmill and cycle (r = 0.983 and r = 0.905, respectively). All other CPET variables demonstrated high intrarater reliability on both modalities, with the exception of VO_2Peak on the cycle ergometer (fair agreement r = 0.400).
CPET in patients with AAAs is a reliable tool test and among CPET test reviewers for common testing modalities/protocols. These findings provide further support for the use of CPET, especially treadmill walking, as a clinical measure of perioperative cardiorespiratory fitness in patients with AAAs.
Diastolic dysfunction and exercise capacity in patients with metabolic syndrome and overweight/obesity
2019, IJC Heart and Vasculature
Citation Excerpt :
The mass of the left ventricle was estimated using the Devereux formula and the E/e′ ratio from dividing the E wave velocity at the mitral valve by the average mitral annulus velocity, e′ (obtained by calculating the mean of the lateral and septal velocities). Participants performed a symptom-limited peak exercise test on a treadmill (General Electric model T2100) following the ramped Bruce treadmill test protocol [14] with continuous electrocardiographic monitoring. Expired gases were analysed with a spiroergometry system (MetaLyzer 3B, Firmware Version 2.0, Cortex, Leipzig.
Left ventricle diastolic dysfunction (LVDD) is a common finding in high risk individuals, its presence being associated with reduced exercise capacity (EC). We assessed the prevalence of LVDD, applying the 2016 guidelines of the American Society of Echocardiography (ASE)/European Association of Cardiovascular Imaging (EACVI), in a population with overweight/obesity and metabolic syndrome and its association with EC.
This was a prospective, cross-sectional study of a cohort of 235 patients (mean age of 65 ± 5 years old and 33% female) without heart disease and an ejection fraction >50% who underwent a complete echocardiographic assessment and cardiopulmonary exercise testing. Individuals meeting three or more criteria of the 2016 ASE/EACVI guidelines are considered to have LVDD, while tests are considered indeterminate in those meeting only two. Overall, 178 (76%) of our patients met one echocardiographic cutoff value for LVDD, 91 (39%) met two and 7 (3%) three or more. Patients meeting three cutoffs values showed a significant reduction in maximal oxygen uptake (16 ± 3 vs. 19.6 ± 5 ml/kg/min, p < .05), unlike those with indeterminate tests. In multiple regression analysis, meeting three cutoffs was associated with number of METS (ß = −2.2, p = .018). In exploratory analysis, using two criteria based on cutoffs different from those proposed in the guidelines, we identified groups with different EC.
The application of 2016 ASE/EACVI guidelines limited the prevalence of LVDD to 3%. This group showed a clear reduction of the EC. New echocardiographic cutoff values proposed in this study allow us to establish subgroups with different levels of EC.
Cardio respiratory response: Validation of new modifications of Bruce protocol for exercise testing and training in elite Saudi triathlon and soccer players
2019, Saudi Journal of Biological Sciences
Citation Excerpt :
These two regressions may illustrate the increased VO2max with test protocol duration, with a non-significant high HR level that may put the cardiovascular system under stress, and may reduce the cardiovascular risk during both exercise training and testing. On the other hand, many studies that have investigated the Bruce protocol using the mean rating of perceived exertion from the revised Borg scale (0 to 10), recorded the value of 8 ± 1 (Peter and James, 2005). This can be considered to be higher than the mean rating of perceived exertion recorded by the subjective responses of the subjects in the test, which had an average rating of perceived exertion with a value of 6 ± 1 for triathlon players, and 5 ± 1 for football players.
The Bruce protocol is the traditional method used to assess maximal fitness level, although it may have limitations, such as its short duration and large work rate increases, with very high levels of exertion that consist of speed/incline combinations. Modifications have been added to elicit similar maximal fitness achievements. The authors of this experimental trial have proposed a new treadmill protocol that allows optimal test duration in conjunction with peak oxygen consumption ‘VO2max’, and with appropriate patient comfort and safety during both exercise testing and training.
Twenty-two elite Saudi players, comprising eleven Saudi triathlon athletes, and eleven Saudi elite soccer players, BMI, body fat mass percentage, body fat free mass percentage. cardiovascular parameter; including, absolute and relative “VO2max” as well as maximal heart rate “HR max”, were assessed during a graded treadmill running modified protocol, using a Quark Cardio Pulmonary Exercise Testing Unit (CPET).
Descriptive statistics were used to obtain the anthropometric characteristics, including comparisons between the means, independent sample T-test and a regression analysis, to test the association of the protocol duration and the corresponding, dependent variables.
It is often difficult to achieve a high cardiorespiratory response, VO2max, without an association to high values of HR max, and peak perceived exertion. This may lead to cardiovascular risk. Our new modifications can provide a practical, valid alternative protocol to be used comfortably both during exercise testing and training, rather than performance testing only, to achieve high VO2max with minimal cardiovascular stress.
Humans are able to self-paced constant running accelerations until exhaustion
2018, Physica A: Statistical Mechanics and its Applications
Citation Excerpt :
Indeed, the present results showed that it is possible to apply a self-paced, ramp-like running protocol on a real running track. Regardless of the acceleration intensity level (“soft”, “medium” or “hard”), the protocol uses a continuous change in speed and brings the subjects to exhaustion in approximately 2 min and 30 s to 20 min; this meets the criteria for clinical exercise testing issues by the relevant international organizations (American College of Sports Medicine 2000, American Thoracic Society 2003, [33–35]). To the best of our knowledge, a human’s ability to maintain constant acceleration in a conscious way until exhaustion has not yet been investigated.
Although it has been experimentally reported that speed variations is the optimal way of optimizing his pace for achieving a given distance in a minimal time, we still do not know what the optimal speed variations (i.e. accelerations) are. At first, we have to check the hypothesis that human is able to accurately self-pacing its acceleration and this even in a state of fatigue during exhaustive self-pacing ramp runs. For that purpose, 3 males and 2 females middle-aged, recreational runners ran, in random order, three exhaustive acceleration trials. We instructed the five runners to perform three self-paced acceleration trials based on three acceleration intensity levels: ”soft”, ”medium” and ”hard”. We chose a descriptive modelling approach to analyse the behaviour of the runners. Once we knew that the runners were able to perceive three acceleration intensity levels, we proposed a mean-reverting process (Ornstein–Uhlenbeck) to describe those accelerations: $d a_{t} = - θ (a_{t} - a) d t + σ d W_{t}$ where $a$ is the mean acceleration, $a_{t}$ is the measured acceleration at each time interval $t$ , $θ$ the ability of the runner to correct the variations around a mean acceleration and $σ$ the human induced variations. The goodness-of-fit of the Ornstein–Uhlenbeck process highlights the fact that humans are able to maintain a constant acceleration and are able to precisely regulate their acceleration (regardless of its intensity) in a run leading to exhaustion in the range from 1 min 36 s to 20 min.
Evaluating the Effects of an Enhanced Strength Training Program in Remote Cardiological Rehabilitation: A Shift from Aerobic Dominance—A Pilot Randomized Controlled Trial
2024, Journal of Clinical Medicine
The effect of repeated coffee mouth rinsing and caffeinated gum consumption on aerobic capacity and explosive power of table tennis players: a randomized, double-blind, placebo-controlled, crossover study
2024, Journal of the International Society of Sports Nutrition

View all citing articles on Scopus

^☆: Reprint requests: Peter M. Will, MD, Suite 2020, Doctors Office Bldg, 301 S. 7th Ave., West Reading, PA 19611.

^☆☆: 0002-8703/99/$8.00 + 0 4/1/95346

View full text

Exercise testing: Improving performance with a ramped Bruce protocol☆,☆☆

Abstract

Section snippets

Methods

Results

Discussion

Am Heart J

J Am Coll Cardiol

J Nucl Cardiol

Am J Cardiol

Am Heart J

Chest

Am J Cardiol

Exercise testing of patients with coronary artery disease

Ann Clin Res

An experimental study of physical fitness of air force personnel

US Armed Forces Med J

Textbook of work physiology

Maximal treadmill stress testing for cardiovascular evaluation

Circulation