Treadmill Ergometry Research Articles

Lactate in cardiac rehabilitation

Training increases work capacity and concomitantly quality of life, and also, according to new data, the life expectancy of patients with coronary heart disease and heart failure. At the same time, the importance of adequate training intensity increases aiming at low complications and high efficacy. The objective of the present work is to define objective training guidance parameters in cardiac rehabilitation. Maximal exercise capacity must be distinguished from the performance without symptoms of oxygen deficit. The latter used to be early surpassed in untreated stabile angina pectoris. Within the last decade optimized therapy often yields a cardiac performance limit above the anaerobic threshold derived from lactate measurements. The concepts of aerobic and anaerobic thresholds derived from the lactate performance curve are introduced and modified leaving the 4 mmol/l lactate threshold concept to meet the criteria for performance capacity and breaking point in cardiac patients. The relationship to threshold concepts derived from spirometric data is mentioned as well as from stress hormones. The heart rate at the anaerobic threshold measured at treadmill ergometry systematically lies above the one from bicycle ergometry. Lactate increases faster with advancing age and the anaerobic threshold is earlier reached and progressively so because of the reduced muscle mass and reduced endurance capacity of people of the industrialized countries. The determination of the anaerobic threshold as an objective criteria independent of motivation leads to training control, as shown by an example. Ineffective training above the threshold giving rise to catecholamines can be avoided by lactate performance diagnostic. Additionally, the success of rehabilitation measures can objectively be quantified and documented much better from the threshold work capacity than from maximal exercise tolerance. Preliminary reports indicate the importance of lactate diagnostics for rehabilitation guidance in heart failure.

Relationship between oxygen consumption and body mass during treadmill and cycle ergometry respectively

In order to study how oxygen uptake can best be scaled to body mass during exercise tests, according to a linear and allometric model, thirteen young male soccer players randomly performed a maximal incremental exercise on both a cycle and treadmill ergometer. The anaerobic threshold (AT) and Threshold of Respiratory Compensated Acidosis (TRCA) were determined from respiratory gas exchange (RGE) parameters. During cycle ergometry, at AT, TRCA and at maximal oxygen consumption (VO2 max), the allometric model normalizes oxygen consumption (VO2) to body weight by dividing the measured value of O2 uptake by body mass raised to the power 0.75. For treadmill running, the suitable body mass exponents were 1.22, 0.94 and 0.75, at AT, TRCA and VO2 max, respectively. For both ergometers, a linear allometric model divides the measured physiological variable values by total body mass. Results show that the allometric function defined above differs between the two ergometers at the AT and TRCA while the difference was negligible at VO2 max. When expressing VO2 to body mass raised to the appropriate mass exponent, at the AT and TRCA respectively, the oxygen uptake was larger for cycling than for running. At VO2 max, the difference between ergometers was not significant. However, when VO2 measures were expressed by the linear model (ml • min−1 · kg−1), the reverse was observed for submaximal exercise: VO2 was greater in value for submaximal treadmill running but no difference was found at VO2 max.

Cardiorespiratory Responses of Trained Boys to Treadmill and Arm Ergometry: Effect of Training Specificity

The purpose of this study was to examine the maximal cardiorespiratory responses of trained adolescent male swimmers (SWM, N = 18), soccer players (SOC, N = 18), and moderately active reference subjects (CON, N = 16) to treadmill running (TRD) and arm ergometry (ARM). Mean values (±SD)for skeletal age were similar among the three groups (12.5± 1.9, 12.7 ± 1.1, and 12.5 ± 1.6 years, for the SWM, SOC, and CON, respectively). Allometric scaling procedures, relating VO2max and body mass, were used and mass exponents of .80 and .74 were identified for TRD and ARM data, respectively. During TRD testing SOC attained significantly higher VO2max values when expressed in ml · kg−1 · min−1, or ml · kg−0.80 · min−1 than the other two groups. However, during ARM testing, the SWM achieved significantly higher VO2peak values (ml · kg−0.74 · min−1 and scaled to arm-CSA) than SOC. The ratio of ARM-VAT to TRD-VAT was significantly higher in SWM (50.1± 9%) compared to SOC (41.2±5%), or CON (41.9 ± 6%).

Rectal and esophageal temperatures during upper- and lower-body exercise.

This study investigated the question: is core temperature measurement influenced by whether exercise involves predominantly upper- or lower-body musculature? Healthy men were allocated to three groups: treadmill ergometry (T) n = 4, cycle ergometry (C) n = 6 and arm crank ergometry (AC) n = 5. Subjects underwent an incremental exercise test to exhaustion on an exercise-specific ergometer to determine maximum/peak oxygen consumption (VO2max). One week later subjects exercised for 36 min on the same ergometer at approximately 65% VO2max while temperatures at the rectum (T(re)) and esophagus (T(es)) were simultaneously measured. The VO2max (1 x min(-1)) for groups T [4.76 (0.50)] and C [4.35 (0.30)] was significantly higher than that for the AC group [2.61 (0.24)]. At rest, T(re) was significantly higher than T(es) in all groups (P < 0.05). At the end of submaximal exercise in the C group, T(re) [38.32 (0.11) degrees C] was significantly higher than T(es) [38.02 (0.12) degrees C, P < 0.05]. No significant differences between T(re) and T(es) at the end of exercise were noted for AC and T groups. The temperature difference (T(diff)) between T(re) and T(es) was dissimilar at rest in the three groups; however, by the end of exercise T(diff) was approximately 0.2 degrees C for each of the groups, suggesting that at the end of steady-state exercise T(re) can validly be used to estimate core temperature.

Standardized aerobic walking on the treadmill by healthy probands and patients with mitochondrial and non-mitochondrial myopathies

Mitochondrial myopathies are characterized by an abnormal aerobic metabolism. The present study examines the serum lactate concentration during standardized aerobic treadmill ergometry and evaluates its relevance for the diagnosis of mitochondrial myopathies. The present study includes 50 volunteers without neuromuscular disorders (control group), 13 patients with mitochondrial, and 14 patients with non-mitochondrial neuromuscular disorders. All members of the control group were able to walk 15 minutes on the treadmill at a constant velocity of at least 5 km/h without exceeding the aerobic threshold (2 mMol/l lactate, venous blood). Ten patients with mitochondrial myopathies and 4 patients with non-mitochondrial myopathies already exceeded the aerobic threshold at walking velocities of 4 or 5 km/h. Though indicating a reduced aerobic endurance, a pathological test result does not prove the diagnosis of a mitochondrial myopathy. Sensitivity and specificity of treadmill ergometry did not differ significantly from those reported for bicycle ergometry. Thus, using the most common aerobic activity in daily life, treadmill ergometry can be considered as an alternative to bicycle exercise tests in the assessment of mitochondrial abnormalities.

Pronation angle of the rear foot during running in relation to load

In 20 volunteers the relationship between rear-foot pronation and increasing physical exertion during treadmill ergometry was examined. In order to assess the influence of regularly performed running training a group of 10 endurance trained middle- and long-distance runners (age: 27.4 +/- 4.9 years; weight: 71.0 +/- 8.8 kg; height: 184.2 +/- 8.3 cm) was compared to another group of 10 untrained subjects (age: 24.7 +/- 2.1 years; weight: 73.3 +/- 9.8 kg; height: 179.1 +/- 8.3 cm). The examinations were carried out on a treadmill using a high-frequency motion analyzing system. Heart rate, blood lactate as well as rear-foot pronation were measured. Regarding heart rate and lactate concentration there were significant differences between trained and untrained volunteers. The pronation angle increased with higher speed up to a maximum of 6.54 +/- 4.22 degree for the trained group and 6.84 +/- 4.59 degree for the untrained group. With reference to maximal as well as submaximal stages the pronation angles showed no significant differences between both groups. Following the maximal exercise level the runners performed an additional 3 min run with a velocity reduced by 8 km/h compared to the maximal speed. At this level the total group as well as the untrained group showed significantly greater pronation angles compared to those of the corresponding velocity at the beginning of the test. The extent of the differences, however, was not significantly correlated with the lactate levels. Our results demonstrate that the increase of the pronation angle is a function of the running speed. But there is also an influence of fatigue, which depends neither on the running velocity nor on the lactate levels during exercise. Therefore, further investigations should emphasize the question which factors are responsible for this effect.

RECTAL AND ESOPHAGEAL TEMPERATURES DURING UPPER AND LOWER BODY EXERCISE1200

This study investigated the question: Does temperature measured simultaneously in the rectum and esophagus during upper and lower body exercise provide the same estimate of core temperature (Tcore)? Healthy men were allocated to 3 groups: treadmill ergometry (T) N=4, cycle ergometry (C) N=6 and arm crank ergometry (AC) N=5. Subjects underwent an incremental exercise test to exhaustion on an exercise specific ergometer to determine˙VO2max. One week later subjects exercised for 36 mins on the same ergometer at approximately 65% ˙VO2max while temperature in the rectum (Tre) and esophagus (Tes) was simultaneously measured. The˙VO2max (l.min-1) for T (4.76 ± 0.50) and C (4.35± 0.30) groups were significantly higher than the AC group (2.6± 0.24). ˙VEmax (l.min-1) was significantly higher in the T (134 ± 13.1) and C (132 ± 9) groups than the AC (96± 2.5) group. At rest, Tre was significantly higher than Tes in all groups (P<0.05). At the end of submax exercise, Tre (38.32 ± 0.11°C) was significantly higher than Tes (38.02 ± 0.12°C) in group C. No significant differences between Tre and Tes at the end of exercise were noted for AC and T groups. At a similar relative intensity (65%˙VO2 max), Tes between the T (38.22 ± 0.14°C) and C(38.02 ± 0.12°C) groups was not significantly different, but the Tes (37.31 ± 0.17°C) in AC group was significantly lower than all other groups. In summary, Tes and Tre do not provide the same estimate of Tcore during cycling, but during arm cranking and running, Tes and Trec are not significantly different.

Effect of an Acute β-Adrenergic Blockade on the Relationship Between Ventilatory and Plasma Lactate Threshold

The present study assesses interobserver variability and day-to-day reproducibility of ventilatory threshold T(ven) and lactate threshold T(lac) in healthy young men. The data were obtained before and after acute beta-adrenergic blockade with metoprolol (100 mg/d p.o.). Fifteen healthy young men underwent progressively increased treadmill ergometry tests on two separate days (day 1, 2). Ten out of fifteen subjects participated in a third exercise test under an acute beta-adrenergic blockade (day 3). Interobserver variability of oxygen uptake at T(ven) (8%; +/- 0.136 l/min) and T(lac) (5%; +/- 0.984 l/min) was small and day-to-day reproducibility of T(ven) (7%; +/- 0.131 l/min) and T(lac) (7%; +/- 0.133 l/min) high. Under acute beta-adrenergic blockade T(ven) occurred at a significantly lower work load (360 +/- 117 s) as compared with T(ven) of days 1 and 2 (477 +/- 153 s; p < 0.05), and T(lac) of day 3 after beta-adrenergic blockade (456 +/- 76 s; p < 0.05). Therefore, a significantly lower oxygen uptake (1.409 +/- 0.29 l/min) could be observed at T(ven) of day 3 as compared with T(ven) of days 1 and 2 (1.852 +/- 0.30; p < 0.001), and T(lac) of days 1 and 2 (1.724 +/- 0.22; p < 0.001). There was a significant linear correlation between oxygen uptake at T(ven) and T(lac) before beta-adrenergic blockade (r = 0.86; p < 0.001). This correlation, however, was lost following an acute beta-adrenergic blockade (r = 0.56; n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)

Ventilatory Threshold and Peak Exercise Response in Athletes with CP during Treadmill and Cycle Ergometry

Little is known about the responses to graded exercise in athletes with cerebral palsy (CP). This study compared the ventilatory threshold (VT) and peak VO2 among athletes with CP during treadmill and cycle ergometry exercise. Six (4 men, 2 women) track athletes with CP volunteered to participate in the study. Graded exercise tests on a treadmill and cycle ergometer were performed on separate days to assess VT and peak VO2. Paired t tests were used to compare the two exercise modes. The VT, expressed as a percentage of peak VO2, was significantly higher on the cycle ergometer than on the treadmill. The absolute VO2 at the VT was similar during both testing modes, and peak VO2 was significantly higher on the treadmill than on the cycle ergometer. Similar to responses seen in able-bodied individuals, the VO2 at VT was similar during both modes of exercise, while the peak VO2 was 10% lower on the cycle than on the treadmill. Cycle ergometer peak VO2 in these athletes was higher than previous reports of individuals with CP for the cycle ergometer.

Exercise studies with elderly volunteers.

The practicalities of conducting exercise studies with elderly and very elderly people have not been well described. In order to help others plan and perform such studies we describe our experience of recruiting volunteers, applying selection criteria, measuring strength, power, cardiorespiratory responses, and potentially related functional abilities. Exclusion criteria are offered, for safety and to characterize subjects as free of disease which might alter their exercise performance. International agreement on these, or similar, criteria would be valuable. The budget must be adequate for prolonged recruitment before a study and for the liberal use of taxis during it. With healthy subjects in their seventies, the coefficients of variation (CV) for repeated measurements of strength and power were: handgrip 3%, isometric knee extension 6%, isometric elbow flexion 6%, and lower limb extensor power 9%. CV for isometric knee extension by healthy subjects in their eighties was 4%. Treadmill ergometry is more time-consuming than with younger subjects. During progressive treadmill tests, the heart rate interpolated to oxygen consumptions of 10 and 15 ml.kg-1.min-1 had CV = 4% and 7%, respectively.

Unterschiede im Leistungsverhalten von Gesunden zwischen Fahrrad- und Laufbandergometrie

Objective: In Terms of endurance training (terrain cure), treadmill ergometry was used as a test method for recording the success of the cure, straining the same muscles which are under strain during the training.

Hemodynamic and Respiratory Responses to Maximal Treadmill and Arm Ergometry Exercise in Men With Chronic Obstructive Pulmonary Disease

Hemodynamic and Respiratory Responses to Maximal Treadmill and Arm Ergometry Exercise in Men With Chronic Obstructive Pulmonary Disease

Haemodynamic and oxymetric investigations on patients under rate-responsive dual-chamber stimulation during exercise.

Rate-response dual-chamber pacing combines the advantages of atrio-ventricular synchrony and rate adaptation in patients suffering from binodal disease. However, it is not known if patients really benefit from the additional rate response under exercise conditions. Therefore, 15 patients suffering from binodal disease received rate-responsive dual-chamber pacemakers. 1, 3, and 6 months postoperatively haemodynamic parameters and oxygen consumption were measured during treadmill ergometry under conventional (DDD) and rate-modulated AV-universal stimulation (DDDR). Using the NCCOM3-R7 (Osypka) technique, rate (f), cardiac index (CI), stroke volume index (SVI), and the end-diastolic volume index (EDVI) were determined non-invasively. Oxygen consumption (VO2) was measured with the Biotec Oxysuper. Based on preoperative status (NYHA) and ventricular contractility, which was determined by means of echocardiography, the patients were divided into two groups: Group I (n = 8) with normal ventricular contractility demonstrated a moderate increase of intrinsic heart rate during exercise. Group II (n = 7) with impaired ventricular contractility showed only a slight or no increase in intrinsic heart rate. When comparing DDD and DDDR pacing a significant increase of CI and VO2 was found for the rate-modulated pacing mode in group II. The reverse was found for patients of group I. The difference between the two groups was statistically significant. According to these results, only patients with nearly no increase in intrinsic sinus heart rate and impaired ventricular function can be expected to benefit from the additional rate-adaptation of a dual-chamber pacemaker.

Training - Overtraining. A Prospective, Experimental Study with Experienced Middle- and Long-Distance Runners*

Overtraining may be one frequent cause of stagnation or decrease in performance capacity of athletes. Israel (19) differentiates between addisonoid (parasympathetic) and basedowoid (sympathetic) overtraining, characterized by inhibition or excitation. We tried to induce an overtraining syndrome in 8 experienced middle- and long-distance runners, based on an increase in training volume from an average 85.9 km (week 1) to 115.1 km (week 2) and 143.1 km (week 3) to 174.6 km per week (week 4). The influence of this training on cardiovascular, metabolic and hormonal parameters was examined with special respect to plasma and urinary catecholamines. Laboratory testing including graded treadmill running was performed on the days 0, 14 and 28. Training was held six days each week, with nearly 30 km per day in the fourth week. A stagnation in endurance performance capacity (running velocity at the aerobic-anaerobic transition range) and a decrease in maximum working capacity were observed in 6 and a stagnation in 2 of the 8 sportsmen, indicated by a decrease in total running distance from 4719 + 912 m to 4361 + 788 m during incremental treadmill ergometry. The sportsmen could neither improve nor could they even approximately reach their personal records during the subsequent competitive season. Subjective complaints, classified on a four-point scale, increased from 1.2 (week 1) to 3.2 in week 4. Glucose, lactate, ammonia, glycerol, free fatty acids, albumin, LDL, VLDL cholesterol, hemoglobin level (transient), leukocytes, and heart rate (before and during exercise) decreased significantly. Urea, creatinine, uric acid, GOT, GPT, gamma-GT, serum electrolytes (except phosphate and calcium) remained constant at the measuring times, CPK was elevated.(ABSTRACT TRUNCATED AT 250 WORDS)

The Six‐Minute Walk—An Adequate Exercise Test for Pacemaker Patients?

In many pacemaker patients bicycle and treadmill ergometry are not practicable. As an alternative, we performed a 6-minute walk on a 20-m corridor in 97 pacemaker patients, who were asked to walk as far as possible determining their speed by themselves. Results were compared with those of bicycle ergometry in 42 of these patients and with treadmill exercise of a group of 92 other pacemaker patients. In the 6-minute walk, performance and maximal heart rate were slightly lower (49 +/- 18 W; 96 +/- 23 beats/min) than in bicycle (57 +/- 16 W; 110 +/- 26 beats/min) and treadmill ergometry (50 +/- 37 W; 102 +/- 35 beats/min). A good correlation was found between walking and bicycling (r = 0.74) and in subgroups of patients with different pacemaker indications. All patients preferred the walk to bicycle ergometry considering it to be more related to daily physical activity. In conclusion, a 6-minute walk is a simple and physiological exercise test for nearly all pacemaker patients with good correlation to other types of exercise. It seems to be preferable to other tests because of its better acceptance and practicability.

Treadmill Ergometry and Heart-Volumes in Elite Biathletes: A Longitudinal Study*

In a retrospective study in elite biathletes we investigated to what extent spiroergometric data, determinations of the anaerobic threshold and measurements of heart volume were related to former training programs, respectively subsequent achievements in competition. Between 1980 and 1987 top athletes of international (team A) as well as of national class (team B) underwent maximal graded treadmill tests in the laboratory. Twice a year maximal oxygen uptake (ml/kg.bw/min), maximal treadmill velocity (km/h), oxygen uptake and treadmill velocity at the anaerobic threshold (defined at 4 mmol/l lactate) were measured during maximal exercise, and absolute and relative heart-volume (heart volume/kg.bw) were evaluated at rest. Evaluation of ergospirometric and heart volume data revealed some relationship to various forms and intensities of training. Observations of team A athletes showed that up to 1985 there was a fairly good relationship between ergospirometry findings and achievements in competition during the following season. For heart volume, however, no such relationship could be found. The skating method introduced in cross-country skiing in 1985 gave more importance to the running technique than to absolute endurance capacity. From this time on the predictive value of laboratory tests clearly diminished.

Treadmill and Swim Bench Ergometry in Triathletes, Runners and Swimmers

Treadmill and Swim Bench Ergometry in Triathletes, Runners and Swimmers

PRESCRIBING WATER-BASED EXERCISE FROM TREADMILL AND ARM ERGOMETRY IN CARDIAC PATIENTS

This study investigated the appropriateness of prescribing upright water-based exercise from treadmill and arm ergometry in uncomplicated, trained patients with cardiovascular disease (CVD) who were accustomed to water-based activities. Ten male patients with established CVD (mean age 59.4 +/- 8.7 yr) underwent maximal treadmill and arm ergometry in randomized counterbalanced order (half of the patients completed the treadmill test first and the other half completed the arm ergometer test first). Electrocardiographic (ECG), rating of perceived exertion (RPE), and oxygen uptake (VO2) measurements were made during both tests. Patients performed upright water-based exercise at 60, 70, and 80% of their maximal treadmill heart rate for 6 min at each intensity in a heated pool with a water temperature of 28-30 degrees C. They also performed an easy tethered swim, defined as performing at a comfortable exercise intensity, eliciting a heart rate of 86% of the treadmill maximum. VO2 and RPE were collected for all water-based exercise. To compare the RPE and VO2 between water-based, treadmill, and arm ergometry exercise, individual regression equations were constructed between heart rate, VO2, and RPE for both treadmill and arm ergometry tests. VO2 and RPE were then compared at the same heart rates between the three exercise modes. At 60% intensity, treadmill exercise exhibited a higher VO2 than water-based and arm ergometry exercise (P less than 0.05) but similar RPE. At 70%, treadmill exercise still yielded higher VO2, but also lower RPE than (P less than 0.05) and arm ergometry exercise (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Experience with the Rate Responsive Pacemaker Sensolog® 703

Pacemaker therapy with rate responsive systems becomes increasingly more important. Numerous clinical and experimental trials have been conducted thus far to investigate different sensors of metabolic demands of the body, functioning independently of an atrial electrogram. To transform mechanical energy into electrical energy, activity-triggered systems utilize a piezo-quartz as their sensor. Thirty five patients suffering from pathological bradyarrhythmias and therefore from an inadequate increase of the heart rate during exercise were supplied with a Sensolog 703. Clinical follow-up was first performed with the help of treadmill ergometry, later on by walking on flat ground and climbing steps. The settings due to the first test caused inadequately high stimulation rates. A 24-h-Holter-ECG was necessary to control the programming and the rate profile in the patient's daily life. Using only the histogram and the rateread function, all rate adaptive parameters of the Sensolog 703 could be set by walking on flat ground and climbing steps. We defined a frequency of 75-85 min-1 to be appropriate during walking, respectively "low work." Individual programming ranged from 2-5/8-15/high-low/very fast-medium/fast-medium (slope, threshold, gain, reaction and recovery time). Reprogramming based on 24-h-Holter ECG was only necessary if the pacemaker was formerly adjusted with the help of treadmill ergometry. Besides, we observed an increase of the stimulation rate due to vibrations not related to exercise, e.g., by driving in a car.

Sports-specific fitness testing in squash.

Maximum oxygen uptake and the running speed at the anaerobic threshold were determined during treadmill running. Performance in these laboratory tests and performance on a squash-specific field test were compared and examined with respect to subjective ratings of squash fitness. The field test was performed in a squash court. Six light bulbs were connected to a programming device causing individual bulbs to light up in a given sequence. The players were instructed to react to the flashes by running towards and striking balloons mounted in the vicinity of the bulbs. By altering the interval between the lighting of the bulbs the intensity of exercise could be varied. The test consisted of a series of 3 min periods of exercise at increasing intensities (increased number of runs per unit of time). The results showed a low correlation (r = 0.52) between treadmill ergometry data and a rank-order list based on an independent, partly subjective estimate of fitness. A higher correlation (r = 0.90) was found for the results of the field test and the rank-order list. Maximum oxygen uptake values and anaerobic threshold values derived from laboratory measurements were thus not sufficient for a valid estimate of competition fitness in these players. The results show that a valid estimate of fitness can be derived from measurements involving exercise closely resembling that which is specific for the sports activity in question. Improved training advice and guidance may result from such studies.