Effects of high intensity resistance and low intensity endurance training on myosin heavy chain isoform expression in highly trained rowers.

An important mechanism of muscle adaptation to exercise is the alteration of myosin heavy chain (MHC) isoform expression. This study investigated the effect of a high intensity resistance training (HIRT) and a low intensity endurance rowing (LIER) on MHC isoform expression in highly trained human muscle. Six well-trained male rowers underwent a training program consisting of a 3-week HIRT and a 3-week LIER, each followed by one-week of recovery. Muscle samples were taken from vastus lateralis before and at the end of each training and recovery phase. MHC isoform was analyzed by SDS-PAGE using silver stain and MHC isoform mRNA by RT-PCR. The maximum oxygen uptake and power output did not change after the training. MHC isoform composition did not change over HIRT or LIER, and there was a decrease in MHC I with concomitant increase in MHC IIa after recovery following HIRT. HIRT led to mRNA upregulation of MHC Ialpha, Ibeta and IIx (127 %, 148 % and 117 %, respectively, p < 0.05), but not MHC I protein (60 % vs 62 %, NS), and LIER led merely to MHC Ibeta mRNA upregulation (131 %, p < 0.05). Thus, different responses of MHC isoform expression to HIRT and LIER occurred in the highly trained muscle, and a "ceiling effect" in terms of MHC I expression could be observed. The upregulation of MHC Ialpha mRNA in human skeletal muscle documented in this study may encourage further observations in this field.

Training intensity influences leptin and thyroid hormones in highly trained rowers.

Leptin (L) is associated with body-weight-regulating and adipostatic functions. Its receptors also may be found centrally. Thyroid hormones regulate metabolic processes mainly by binding at peripheral receptors. Aim of this study was to show if there is a link between those central and peripheral regulation systems and to investigate the influence of different training intensities on L and the hypothalamic-thyroid-axis (HTA) in highly trained rowers. Six rowers (18.9 +/- 2.6 y; BMI 22.8 +/- 2.1 kg/m (2)) undertook high intensity resistance training (RT) for three weeks followed by three weeks of endurance training (ET). After each training cycle the subjects had one week for recovery (R1, R2). Blood samples were taken before and at the end of RT, R1, ET and R2. L, thyroid stimulating hormone (TSH), free T3 (fT3) and free T4 (fT4) were measured. After RT, a significant reduction in L, TSH and fT3 was found (p < 0.05). fT4 was unchanged. L remained decreased until the end of R1. After ET, a significant increase of TSH was found. L correlated to basal TSH levels (r = 0.49, p = 0.006) during R. BMI and body fat were unchanged throughout the study and were not correlated with hormonal levels. We speculate a high energy flux during intensified training (RT) caused the decrease of L and the HTA, independent of BMI or body fat. Thus, we conclude a depression of L and HTA is associated with training intensity.

Lactate concentration in plasma and red blood cells during incremental exercise.

The purpose of this study was to investigate the distribution of lactate in plasma and red blood cells (RBC) in capillary blood during and after incremental exercise. We measured capillary plasma lactate and whole blood lactate of 10 subjects during incremental treadmill running and the first 20 min of recovery. To minimize lactate exchange from plasma to RBC between sampling and analysis, a recently developed rapid plasma separation method was used. RBC lactate was calculated. The RBC/plasma lactate concentration ratio decreased from 1.0 (0.85-1.28) before to 0.37 (0.25-0.45) after exhaustive exercise (plasma lactate 15.9 (12.2-19.5)mmol x I(-1), RBC lactate 4.8 (4.0-7.0) mmol x 1(-1)), thus showing that capillary plasma lactate increased much more rapidly than intracellular lactate during incremental exercise. In the first 5 minutes of recovery intracellular lactate still rose while plasma lactate already declined. Then both decreased while the concentration ratio as well as the absolute concentration gradient remained nearly constant (ratio 20 min after exercise termination: 0.43 (0.19-0.54).

Human skeletal muscle HSP70 response to physical training depends on exercise intensity.

We have previously reported that HSP70 in human skeletal muscle could be induced by training. However, whether HSP70 induction is dependent upon exercise volume or exercise intensity remains unknown. The aim of the present study was to investigate the relationship between HSP70 and training intensity in rowers. Fourteen well-trained male rowers were divided into two groups (group A, n = 6; group B, n = 8). Group A performed higher intensity exercise during 1st phase, whereas group B performed higher intensity exercise during 2nd training phase. Training volume in 2nd phase increased in both groups. Both training intensity and volume were reduced in 3rd phase. Muscle samples were taken from m. vastus lateralis by fine needle biopsy before training, at the end of the 1st, 2nd and 3rd training phases. HSP70 was quantitatively determined using SDS-PAGE with silver stain. In group A, HSP70 increased significantly from 38 +/- 12 etag before training to 59 +/- 16 etag at the end of the lst training phase (loaded total protein 2.5microg), and decreased afterwards. In group B, HSP70 increase (from 36 +/- 11 etag to 50 +/- 13 etag) in the 1st phase was significantly smaller, there was a further increase of HSP70 in the 2nd phase (60 +/- 14 etag). At the end of the training, HSP70 decreased in both groups. Thus, HSP70 response to training seems to be dependent upon exercise intensity.

Expression of myosin heavy chain isoforms in skeletal muscle of patients with peripheral arterial occlusive disease.

PURPOSE: Peripheral arterial occlusive diseases (PAODs) not only compromise blood flow but lead to a series of subsequent metabolic and structural changes in the relevant muscles. Changes in myofibrillar proteins (eg, of myosin heavy chain [MHC] isoforms), one of the determinants of muscle structure as well as of muscular function, have not been reported in patients with PAOD and were therefore the aim of this study. METHODS: Thirteen consecutive patients with PAOD were examined (clinical stage according to Fontaine II, three patients; III, three patients, and IV, seven patients) and compared with five age-matched control patients who had been in traffic accidents. A calf muscle sample (gastrocnemius muscle) in the ischemic region was taken for MHC isoform analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis and silver stain, and the relative content of MHC isoforms was measured. RESULTS: Compared with the control patients, there was no significant change of MHC isoforms in patients with PAOD II. In patients with PAOD III, MHC IIb decreased significantly (P <.05) although MHC IIa remained unchanged; in patients with PAOD IV, both MHC IIa and IIb decreased significantly (P <.05). Accordingly, there was a progressive increase of the relative amount of MHC I with more critical ischemia in PAOD. CONCLUSION: In patients with PAOD, the content of MHC II decreased with a higher grade of ischemia. That seems to be consistent with an increased resistance to ischemia for myosin isoforms in the order of I more than in IIa more than IIb. Whether the decrease of MHC II in patients with PAOD is related to atrophy of muscle fibers or to muscle-fiber transition must be investigated further.

Training of junior rowers before world championships. Effects on performance, mood state and selected hormonal and metabolic responses.

BACKGROUND: Few data have been published on training of competitive athletes and about metabolic, hormonal and psychological reactions to overreaching (transient over-training) and tapering in successful athletes. METHODS: Training was recorded and effects on mood state and metabolic and hormonal responses were examined in 10 rowers and spares of the coxed eight during preparation for the World Championships 1995. Mood state was determined using the Recovery-Stress-Questionnaire for Athletes. Resting morning blood parameters as well as performance were measured every week over a period of five weeks. RESULTS: Very high training loads of approximately 3.2 hours per day were sustained for 18 days. Maximum performance (Pmax) and maximum lactate (Lamax) were decreased during high-load training phases (overreaching), Pmax, Lamax and endurance increased after the tapering period. There were decreases in gonadal and hypothalamic steroid hormones (fsh, 1h, prolactin, testosterone) during overreaching and increases in these hormones in tapering. Both performance and hormonal indices of training load were reflected by deterioration of recovery in the Recovery-Stress-Questionnaire for Athletes. CONCLUSIONS: Clear signs of overreaching were found after 18 days of intense training of about 3 h.d(-1) in these highly-trained athletes, i.e. decreases in performance, gonadal and hypothalamic steroid hormones and deterioration of recovery in the psychological questionnaire. After tapering values returned to baseline values before the World Championship. The findings indicate that overreaching is an integral part of successful training regimens and can be analyzed by a multi-factorial approach involving biological and psychometric data.

Human skeletal muscle HSP70 response to training in highly trained rowers.

Previous studies have demonstrated exercise-induced heat shock protein 70 (HSP70) in animals. The purpose of this study was to investigate human skeletal muscle HSP70 response to rowing training. Ten male rowers trained for 4 wk with different forms, durations, and intensities of exercise. Biopsy was performed in the right musculus vastus lateralis before training and at the end of each week. HSP70 in 5 microg of total protein from the muscle sample was determined by using Western blot and immunodetection with chemiluminescence technique, by means of laser densitometer referring to a series of known standard HSP70. Compared with pretraining (100%), HSP70 increased during training (181, 405, 456, and 363% from the first to fourth training week, respectively) with the maximum HSP70 production at the end of second training week. Thus HSP70 is induced in highly trained human muscle by long-term training.

Effect of "living high-training low" on the cardiac functions at sea level.

Living high-training low (LHTL), living at high altitude and training at sea level, is reported to be beneficial in enhancing physical performance. Effect of LHTL on cardiac function which is one of major determinants in performance, however, was not examined. To address this issue, 21 well-trained triathletes divided into control (n = 10, living and training at sea level) and LHTL group (living at 1980 m altitude > or = 12 hrs/day and training at sea level) were Doppler echocardiographically examined before and at the end of the two-week program. Heart rate and blood pressure did not change in both groups. At end of the training, left ventricular endsystolic diameter of LHTL group was smaller than that of controls (32 vs 34 mm, P < 0.05). Shortening fraction and ejection fraction in LHTL group increased by 9% and 17 %, respectively, P < 0.05. Preejection period/ejection time was more greatly reduced in LHTL group (P < 0.05). Stroke volume and cardiac output in LHTL increased. Diastolic function was not significantly affected by LHTL. These results suggest that LHTL produced an improvement of systolic function underlined by incremented left ventricular contractility, which might be associated with increased beta-adrenergic receptor or an improved myocardial energy utilization.

Training of rowers before world championships.

In rowing, static and dynamic work of approximately 70% of the body's muscle mass is involved for 5.5 to 8 min at an average power of 450 to 550 W. In high load training phases before World Championships, training volume reaches 190 min.d-1, of which between 55 and 65% is performed as rowing, and the rest is nonspecific training like gymnastics and stretching and semispecific training like power training. Rowing training is mainly performed as endurance training, rowing 120 to 150 km or 12 h.wk-1. Rowing at higher intensities is performed between 4 and 10% of the total rowed time. The increase in training volume during the last years of about 20% was mainly reached by increasing nonspecific and semispecific training. The critical borderline to long-term overtraining in adapted athletes seems to be 2 to 3 wk of intensified prolonged training of about 3 h.d-1. Sufficient regeneration is required to avoid overtraining syndrome. The training principles of cross training, alternating hard and easy training days, and rest days reduce the risk of an overtraining syndrome in rowers.

[Physical training of patients with sleep apnea]. / Körperliches Training bei Patienten mit Schlafapnoe.

PURPOSE: It is a common question of sleep apnoea patients in the sleep lab whether they stand a chance to decrease the symptoms and severity of their disease by physical exercise. As far as we know, there is no data about this specific question until now, even though this has been subject to speculation. A few studies, however, report on an improvement of the respiratory drive (and chemoreceptor sensitivity) after physical exercise in athletes. The aim of this study was to prove whether physical exercise in sleep apnoea patients could improve the symptoms of their disease in an open trial. METHODS: 11 Patients with mild to severe sleep apnoea syndrome (1 f, 10 m, mean age 53.8x) took part in a 6-month period of physical exercise twice a week 2 h each time under the instructions of physical therapists. Before and after the 6mo period a full PSG without CPAP or BIPAP, a bicycle exercise test with lactate profile, echocardiography, blood test, and body weight and body height measurement was performed. Statistical analysis was done using Wilcoxon ranked test and multiple regression analysis. RESULTS: There was no significant bodyweight reduction in all patients after the 6mo period of physical training, no significant difference in either basal SaO2 nor mean SaO2 and no significant improvement in physical status by the p at 4 mmol lactate on the lactate profile. Echocardiographic changes were not found; there was no significant change in the blood pressure profiles during the bicycle test. No cardiopulmonary problems including exercise-induced high blood pressure were reported during the training period. There was, however, a significant decrease of the RDI (p < 0.05), but no significant change in the REM-sleep % of total sleep time (TST) and the TST itself. CONCLUSIONS: There was an improvement of the sleep apnoea syndrome correlated to a decrease of the RDI in the studied patient population due to a possible increase in the respiratory drive or a stabilised muscle tone ine the upper airways after physical exercise, as reported by other authors, because weight reduction could not be the reason in our patients. Our trial showed that the exercise does not increase the severity of symptoms of sleep apnoea by changing the REM/non REM ratio or for any other reasons. A physical training programme for sleep apnoea patients as an additional treatment should therefore be considered.

Training and overtraining: an overview and experimental results in endurance sports.

Overtraining can be defined as "training-competition > > recovery imbalance", that is assumed to result in glycogen deficit, catabolic > anabolic imbalance, neuroendocrine imbalance, amino acid imbalance, and autonomic imbalance. Additional non-training stress factors and monotony of training exacerbate the risk of a resulting overtraining syndrome. Short-term overtraining called overreaching which can be seen as a normal part of athletic training, must be distinguished from long-term overtraining that can lead to a state described as burnout, staleness or overtraining syndrome. Persistent performance incompetence, persistent high fatigue ratings, altered mood state, increased rate of infections, and suppressed reproductive function have been described as key findings in overtraining syndrome. An increased risk of overtraining syndrome may be expected around 3 weeks of intensified/prolonged endurance training at a high training load level. Heavy training loads may apparently be tolerated for extensive periods of time if athletes take a rest day every week and use alternating hard and easy days of training. Persistent performance incompetence and high fatigue ratings may depend on impaired or inhibited transmission of ergotropic (catabolic) signals to target organs, such as: (I) decreased neuromuscular excitability, (II) inhibition of alpha-motoneuron activity (hypothetic), (III) decreased adrenal sensitivity to ACTH (cortisol release) and increased pituitary sensitivity to GHRH (GH release) resulting in a counter-regulatory shift to a more anabolic endocrine responsibility, (IV) decreased beta-adrenoreceptor density (sensitivity to catecholamines), (V) decreased intrinsic sympathetic activity, and (VI) intracellular protective mechanisms such as increased synthesis of heat-shock proteins (HSP 70) represent a complex strategy against an overload-dependent cellular damage.

Validation of the acetylene rebreathing method for measurement of cardiac output at rest and during high-intensity exercise.

The use of the acetylene rebreathing method to estimate cardiac output (CO) during high-intensity exercise, which may be influenced by recirculation of acetylene, has not been validated. This study was designed to validate the acetylene rebreathing method to measure CO during high-intensity exercise using the direct Fick method. CO was measured at rest and during exercise at 25%, 50%, 75% and 90% of the nine subjects' maximum oxygen uptake (VO2max) by the direct Fick and acetylene rebreathing method. CO measured by the acetylene rebreathing method correlated with work rate (r = 0.90, P < 0.01) and with oxygen uptake (r = 0.94, P < 0.01). The correlation coefficient of CO between both methods was r = 0.91 (P < 0.01). There was no significant difference in CO measured by each method at rest as well as at each work rate. The difference in CO between each method was greater at lower CO than at higher CO. At 90% of VO2max, the CO measured by acetylene rebreathing was nearly identical to that measured by the Fick method. It can be concluded that acetylene rebreathing for measurement of CO is valid not only at rest but also during exercise, especially during high-intensity exercise.

Metabolic and hormonal reactions during training in junior oarsmen.

This study evaluated strain reactions in young athletes (mean age: 17.6 years). Of 35 male rowers, 21 were selected by rowing ergometer tests to take part in a 26-day training camp before the World Championships in 1989. Blood samples were obtained in the morning of the day after rowing ergometer tests and on the 16th and 26th day. Cortisol (C), testosterone (T), sexual-hormone-binding globulin (SHBG), urea and creatine kinase (CK) were determined in serum and free testosterone (FT) was calculated. In the nonselected rowers C was 10% higher, FT 20% lower, and CK 42% higher compared to the selected rowers. During training, C was related to the intensity of training. It remained constant in phase 1 (12 days, increased volume of training) and increased in phase 2 (10 days, decreased volume and higher intensity). FT decreased in phase 1 and increased in phase 2. Urea showed a close relationship to training volume. CK levels decreased during the training volume. CK levels decreased during the training period as an adaptation to the training. Despite a high training load, there were no indications of overstrain reactions in these young athletes.

Performance and blood lactate on Gjessing and Concept II rowing ergometers.

The Gjessing (GE) and the wind resistance (Concept II, CII) rowing ergometers were compared in 11 trained subjects during incremental exercise. Maximum power was 255 (200-370) W on GE, but 294 (204-393) W in CII (median and range, p < 0.05). If power was directly measured by a strain gauge and a displacement transducer in the CII, a 5.1% (3.2%-7.8%) higher maximum performance was obtained (314 [223-413] W, p < 0.05). Maximum stroke rates were higher in GE (33 [27-37]/min) than in CII (29 [24-35]/min, NS). Blood lactate increased faster with work rate and lactic anaerobic threshold was therefore lower in GE. Blood lactate was higher for every heart rate for GE compared to CII. This suggests higher anaerobic effort in GE rowing.

Oxygen consumption and metabolic strain in rowing ergometer exercise.

Oxygen consumption (VO2) when rowing was determined on a mechanically braked rowing ergometer (RE) with an electronic measuring device. VO2 was measured by an open spirometric system. The pneumotachograph valve was fixed to the sliding seat, thus reducing movement artefacts. A multi-stage test was performed, beginning with a work load of 150 W and increasing by 50 W every 2 minutes up to exhaustion. Serum lactate concentrations were determined in a 30 s break between the work stages. 61 examinations of oarsmen performing at maximum power of 5 W X kg-1 or more were analysed VO2 and heart rate (HR) for each working stage were measured and the regression line of VO2 on the work load (P) and an estimation error (Sxy) were calculated: VO2 = 12.5 X P + 415.2 (ml X min-1) (Sxy = +/- 337 ml, r = 0.98) Good reproducibility was found in repeated examinations. Similar spiroergometry was carried out on a bicycle ergometer (BE) with 10 well trained rowers and 6 trained cyclists. VO2 of rowing was about 600 ml X min-1 higher than for bicycling in the submaximal stages for both groups. The VO2max of RE exercise was 2.6% higher than for oarsmen on BE, and the cyclists reached a greater VO2 on BE than the oarsmen. No differences were found between RE and BE exercise heart rate. The net work efficiency when rowing was 19% for both groups, experienced and inexperienced: when cycling it was 25% for cyclists and 23% for oarsmen.