Exercise Testing in Sports Medicine

Abstract

Background: Bicycle and treadmill exercise tests are used in sports medicine and occupational medicine to detect latent disease, to monitor treatment, and to measure patients' physical performance ability and reserve. In this review, we describe the indications, contraindications, and manner of performance of these tests, along with the variables tested, criteria for evaluation, (sub)maximal stress, and the factors that affect these tests, including age, sex, and medications.

Methods: This review is based on pertinent articles retrieved by a selective literature search and on the ergometry guidelines of four medical specialty societies.

Results: The proper performance of ergometric stress tests calls for preparation and monitoring by qualified staff as well as standardized testing conditions. Ergometric studies are indispensable as a clinical diagnostic method for the early recognition of disease, for follow-up over time, and for individual counseling. The patient's maximal achievable performance is a predictor of morbidity and mortality. Among the variables that can be measured in the submaximal performance range, the respiratory rate, heart rate, and lactate performance curves are more accurate prognostic predictors than the so-called threshold values (physical working capacity, anaerobic-aerobic threshold). Ergometric stress tests can be used to detect (among other conditions) latent hypertension, pulmonary diseases (e.g., exertional asthma), pabnormal ECG changes, and cardiovascular disorders (e.g., ischemia, arrhythmia, congestive heart failure). The ergometric findings are influenced by the choice of stress-inducing protocol. They provide important information for the planning and monitoring of exercise training and for the treatment of persons suffering from diverse physical conditions, as well as for leisure-time athletes. They are less suit- able for use in the design of training programs for high-performance athletes.

Conclusion: Ergometric stress tests provide important data in clinical and preventive medicine. The findings are often difficult to interpret because of the wide range of normal findings, the use of different stress-inducing protocols, and the lack of gen- erally accepted reference values. The establishment of a nationwide fitness and health registry for ergometric data would be very helpful for the individualized inter- pretation of test findings and for the monitoring of exercise training and therapy.

Figure 1

The probability of a serious cardiovascular event as a function of physical fitness (fitness categories based on the maximal performance attained on the ergometric treadmill; N = 20 590 subjects; figure modified from Kokkinos et al. 2017 [23])

Figure 2

The course of heart rate and lactate concentration in healthy 18- to 35-year-olds undergoing bicycle ergometry (with 4-minute performance steps). The mean values of different performance groups with maximal performance ranging from 160 to 400 W are shown (n = 334). These data were acquired in the setting of diagnostic studies of physical performance carried out at the Institute for Preventive Medicine of the German Federal Armed Forces. The minimum and maximum values and the 5^th, 25^th, 50^th, and 75^th percentiles for each level of performance are listed in eTable 3a (heart rate) and eTable 4a (lactate concentration).

eFigure 1

The course of arterial blood pressure during ergometric testing while seated on an exercise bicycle, with performance increments every 2 minutes (mean ± standard deviation) (1, 4)

eFigure 2

The course of heart rate and lactate concentration in healthy 18- tos 35-year-olds undergoing treadmill ergometry (performance steps of 4 minutes’ duration, with 30-second breaks in between). The figure shows the means obtained in different performance groups whose maximal treadmill speed ranged from 10 to 19 km/h (n = 385). The data were acquired in the setting of diagnostic studies of physical performance carried out in the Institute for Preventive Medicine of the German Federal Armed Forces.