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- Aagaard, Philip, et al.
(författare)
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Early Repolarization in Middle-Age Runners-Cardiovascular Characteristics.
- 2014
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Ingår i: Medicine & Science in Sports & Exercise. - 0195-9131 .- 1530-0315. ; 46:7, s. 1285-1292
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: This study aimed to assess the prevalence and patterns of early repolarization (ER) in middle-age long-distance runners, its relation to cardiac structure and function, and its response to strenuous physical activity. Methods: Male first-time cross-country race participants >45 yr were assessed pre-and postrace by medical history and physical examination, 12-lead ECG, vectorcardiography, blood tests, and echocardiography. ER was defined either as ST elevation or J wave and categorized according to localization and morphology. Results: One hundred and fifty-one subjects (50 +/- 5 yr) were evaluated before the race, and 47 subjects were evaluated after the race. Altogether, 67 subjects (44%) had ER. Subjects with versus without ER had a lower resting HR (56 +/- 8 vs 69 +/- 9 bpm, P = 0.02), lower body mass index (24 +/- 2 vs 25 +/- 3 kg.m(-2), P < 0.001), higher training volume (3.0 +/- 2.6 vs 2.1 +/- 2.7 h.wk(-1), P = 0.03), and faster 30-km running times (194 +/- 28 vs 208 +/- 31 min, P = 0.01). Vectorcardiography parameters in subjects with ER showed more repolarization heterogeneity: vector gradient (QRS-T-area) (120 +/- 25 vs 92 +/- 29 mu Vs, P < 0.001), T-area (105 +/- 18 vs 73 +/- 23 mu Vs, P < 0.001), and T-amplitude (0.63 +/- 0.13 vs 0.53 +/- 0.16 mm, P < 0.001); these parameters were inversely related to HR (r = -0.37 to -0.48, P < 0.001). ER disappeared in 15 (75%) of 20 subjects after the race. Conclusions: ER is a common finding in middle-age male runners. This ECG pattern, regardless of morphology and localization, is associated with normal cardiac examinations including noninvasive electrophysiology, features of better physical conditioning, and disappears after strenuous exercise in most cases. These findings support that ER should be regarded as a common and training-related finding also in middle-age physically active men.
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| 2. |
- Aagaard, Per, 1957, et al.
(författare)
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Preparticipation Evaluation of Novice, Middle-Age Long-Distance Runners.
- 2013
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Ingår i: Medicine and science in sports and exercise. - 0195-9131 .- 1530-0315. ; 45:1, s. 130-137
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Tidskriftsartikel (refereegranskat)abstract
- Abstract PURPOSE: To assess the cardiovascular health and risk profile in middle-aged males making an entry to participate for their first time in a long-distance race. METHODS: Male first-time participants ≥45 years in the world's largest cross-country running race, the Lidingöloppet, were evaluated with a medical history and physical exam, European risk-SCORE, 12-lead ECG, echocardiography and blood tests. Further diagnostic work-up was performed when clinically indicated. RESULTS: Of 265 eligible runners, 153 (58%, age 51±5 y) completed the study. While the 10-year fatal cardiovascular event risk was low (SCORE: 1% (IQR: 0 - 1%)), mild abnormalities were common, e.g. elevated blood-pressure (19%), left ventricular hypertrophy (6%), elevated LDL cholesterol (5%). ECG changes compatible with "athlete's heart" were present in 82%, e.g. sinus bradycardia (61%) and/or early repolarization (32%). ECG changes considered training-unrelated were found in 24%, e.g. prolonged QTc: 13%; left axis deviation: 5.3%; left atrial enlargement: 4%). In 14 runners (9%) additional diagnostic work-up was clinically motivated, and 4 (2%) were ultimately discouraged from vigorous exercise due to QTc intervals >500 ms (n=2), symptomatic atrioventricular block (n=1), and a cardiac tumor (n=1). The physician exam and the ECG identified 12 of the 14 subjects requiring further evaluation. CONCLUSIONS: Cardiovascular evaluation of middle-aged men, including a physician exam and a 12-lead ECG, appears useful to identify individuals requiring further testing prior to vigorous exercise. The additional yield of routine echocardiography was small.
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| 3. |
- Apró, William, 1980-, et al.
(författare)
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Endurance Exercise Does Not Impair mTOR Signalling After Resistance Exercise : D-58 Thematic Poster - Skeletal Muscle Cell Signaling: JUNE 2, 2011 3:15 PM - 5:15 PM: ROOM: 304
- 2011
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Ingår i: Medicine & Science in Sports & Exercise. - 0195-9131 .- 1530-0315. ; 43:5, s. 52-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Resistance exercise is known to stimulate muscle hypertrophy and this effect is mainly mediated by the mammalian target of rapamycin (mTOR) pathway. In contrast, endurance exercise results in a divergent phenotypic response which to a large extent is mediated by adenosine monophosphate-activated protein kinase (AMPK). Research indicates that molecular interference may exist, possibly through an inhibitory effect on mTOR signalling by AMPK, when these two modes of exercise are combined. PURPOSE: To investigate the impact of subsequent endurance exercise on resistance exercise induced mTOR signalling. METHODS: In a randomized and cross-over fashion, ten male subjects performed either heavy resistance exercise (R) or heavy resistance exercise followed by endurance exercise (RE) on two separate occasions. The R protocol consisted of thirteen sets of leg press exercise with 3 minutes of recovery allowed between each set. In the RE session, resistance exercise was followed by 15 minutes recovery after which 30 min of cycling was initiated at an intensity equal to 70 % of the subjects' maximal oxygen consumption. Muscle biopsies were collected before, 1 and 3 hours after resistance exercise in both trials. Samples were analyzed for several signalling proteins in the mTOR pathway using western blot technique. RESULTS: Phosphorylation of mTOR increased approx. twofold at 1 h post resistance exercise and remained elevated at the 3 h time point (p< 0.01) with no difference between the two trials. Phosphorylation of p70S6k, a downstream target of mTOR, was increased about 6-and18-fold at 1 h and 3 h post resistance exercise (p< 0.01). There was no difference in p70S6k phosphorylation at any time point between the two trials. Phosphorylation of the eukaryotic elongation factor eEF2 was decreased 3- to 4-fold at both time points post resistance exercise (p< 0.01) with no difference between trials. Phosphorylation of AMPK was unchanged at the 1 h time point but decreased approximately 30 % from pre-exercise values in both trials at 3 h post resistance exercise (p< 0.01). CONCLUSIONS: The signalling response following heavy resistance exercise is not blunted by subsequent endurance exercise. Supported by the Swedish National Centre for Research in Sports.
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| 5. |
- Björklund, Glenn, 1972-, et al.
(författare)
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Biomechanical influenced differences in O2 extraction in diagonal skiing: arm versus leg
- 2010
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Ingår i: Medicine & Science in Sports & Exercise. - : Lippincott Williams & Wilkins. - 0195-9131 .- 1530-0315. ; 42:10, s. 1899-1908
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Tidskriftsartikel (refereegranskat)abstract
- Biomechanically Influenced Differences in O-2 Extraction in Diagonal Skiing: Arm versus Leg. Med. Sci. Sports Exerc., Vol. 42, No. 10, pp. 1899-1908, 2010. Purpose: This study aimed to determine whether the differences in oxygen extraction and lactate concentration in arms and legs during cross-country skiing are related to muscle activation or force production and how these differences are influenced by a reduction in exercise intensity. Methods: Nine well-trained male cross-country skiers (age = 22 +/- 3 yr, (V) over dotO(2max) = 5.3 +/- 0.3 L.min(-1) and 69 +/- 3 mL.kg(-1).min(-1)) performed diagonal skiing on a treadmill for 3 min at 90% followed by 6 min at 70% of (V) over dotO(2max). During the final minute of each workload, arterial, femoral, and subclavian venous blood was collected for determination of blood gases, pH, and lactate. EMG was recorded from six upper-and lower-body muscles, and leg and pole forces were measured. Cardiorespiratory variables were monitored continuously. Results: Oxygen extraction in the legs was higher than that in the arms at both 90% and 70% of (V) over dotO(2max) (92% +/- 3% vs 85% +/- 6%, P < 0.05 and 90% +/- 3% vs 78% +/- 8%, P < 0.001). This reduction with decreased workload was more pronounced in the arms (-9.8% +/- 7.7% vs -3.2% +/- 3.2%, P < 0.01). EMGRMS for the arms was higher, and pole ground contact time was greater than the corresponding values for the legs (both P < 0.01). At both intensities, the blood lactate concentration was higher in the subclavian than that in the femoral vein but was lowered more in the subclavian vein when intensity was reduced (all P < 0.001). Conclusions: The higher muscle activation (percentage of maximal voluntary isometric contraction) in the arms and the longer ground contact time of the poles than the legs contribute to the lower oxygen extraction and elevated blood lactate concentration in the arms in diagonal skiing. The better lactate recovery in the arms than that in the legs is aided by greater reductions in muscle activation and pole force when exercise intensity is reduced.
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| 8. |
- Bäcklund, Catharina, 1971-, et al.
(författare)
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Validity of an armband measuring energy expenditure in overweight and obese children
- 2010
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Ingår i: Medicine & Science in Sports & Exercise. - : The American College of Sports Medicine. - 0195-9131 .- 1530-0315. ; 42:6, s. 1154-1161
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To examine the ability of the SenseWear Pro2 Armband (SWA) to accurately assess energy expenditure in free-living overweight or obese children during a two-week period, by comparison with energy expenditure measured using the doubly labeled water (DLW) method. A second aim was to examine which software version, Innerview Professional 5.1 or Sensewear Professional 6.0, are the most appropriate for use together with SWA in overweight and obese children. Method: A random sample of 22 healthy, overweight or obese children (11 girls and 11 boys) aged 8-11 years was recruited from an ongoing intervention study. Energy expenditure in free-living conditions was simultaneously assessed with the SWA and DLW methods during a 14-day period. All data from the SWA were analyzed using InnerView Professional software versions 5.1 (SWA 5.1) and 6.1 (SWA 6.1). Results: An accurate estimation in energy expenditure was obtained when SWA 5.1 was used, showing a non-statistically significant difference corresponding to 17 (1200) kJ[middle dot]d-1 compared with the energy expenditure measured using the DLW method. However, when SWA 6.1 was used a statistically significant (18%) underestimation of energy expenditure was obtained, corresponding to 1962 (1034) kJ[middle dot]d-1 compared with the DLW method. Conclusion: The SWA together with software version 5.1, but not 6.1, is a valid method for accurately measuring energy expenditure at group level of free-living overweight and obese children.
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