Veteran athletes exercise at higher maximum heart rates than are achieved during standard exercise (stress) testing

Objective. The stress electrocardiogram (sECG) is routinely used to screen individuals for underlying cardiac pathology before an exercise programme is prescribed. The underlying assumption is that the cardiac responses elicited during the sECG test are similar to those achieved during participation in sportiilg activities. However, this premise may be incorrect since the physical demands of different modes of exercise vary substantially.Design. Ten veteran league squash players (LSP), 10 social squash players (SSP), 10 league runners (LR), 10 social runners (SR) and 10 sedentary individuals (SED) were recruited for the study. All subjects completed a lifestyle questionnaire, a full medical examination and a routine sECG. Thereafter each subject's heart rate (HR) was monitored on two separate occasions while participating in sporting activity.Results. No sECG exercise-induced abnormalities were observed, although five subjects showed resting abnormalities. Maximal HR during the sECG, and maximal and mean HR during the field tests, were not significantly diHerent between groups. However, maximal HR was significantly higher in all groups during their sporting activities than during stress testing in the laboratory (P < 0.01).Conclusions. Maximal HR in veteran athletes during specific sporting activities was significantly higher than that attained during a routine sECG. This finding was not sport-specific, nor was it related to the level of competitiveness of the trial participants. These data show that a routine sECG is a submaximal test of exercise performance, and should be interpreted as such

Carbohydrate Dependence During Prolonged, Intense Endurance Exercise

A major goal of training to improve the performance of prolonged, continuous, endurance events lasting up to 3 h is to promote a range of physiological and metabolic adaptations that permit an athlete to work at both higher absolute and relative power outputs/speeds and delay the onset of fatigue (i.e., a decline in exercise intensity). To meet these goals, competitive endurance athletes undertake a prodigious volume of training, with a large proportion performed at intensities that are close to or faster than race pace and highly dependent on carbohydrate (CHO)-based fuels to sustain rates of muscle energy production [i.e., match rates of adenosine triphosphate (ATP) hydrolysis with rates of resynthesis]. Consequently, to sustain muscle energy reserves and meet the daily demands of training sessions, competitive athletes freely select CHO-rich diets. Despite renewed interest in high-fat, low-CHO diets for endurance sport, fat-rich diets do not improve training capacity or performance, but directly impair rates of muscle glycogenolysis and energy flux, limiting high-intensity ATP production. When highly trained athletes compete in endurance events lasting up to 3 h, CHO-, not fat-based fuels are the predominant fuel for the working muscles and CHO, not fat, availability becomes rate limiting for performance

Pre-cooling for endurance exercise performance in the heat: a systematic review.

PMCID: PMC3568721The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/10/166. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Endurance exercise capacity diminishes under hot environmental conditions. Time to exhaustion can be increased by lowering body temperature prior to exercise (pre-cooling). This systematic literature review synthesizes the current findings of the effects of pre-cooling on endurance exercise performance, providing guidance for clinical practice and further research

Spanish Ketogenic Mediterranean diet: a healthy cardiovascular diet for weight loss

<p>Abstract</p> <p>Background</p> <p>Ketogenic diets are an effective healthy way of losing weight since they promote a non-atherogenic lipid profile, lower blood pressure and decrease resistance to insulin with an improvement in blood levels of glucose and insulin. On the other hand, Mediterranean diet is well known to be one of the healthiest diets, being the basic ingredients of such diet the olive oil, red wine and vegetables. In Spain the fish is an important component of such diet. The objective of this study was to determine the dietary effects of a protein ketogenic diet rich in olive oil, salad, fish and red wine.</p> <p>Methods</p> <p>A prospective study was carried out in 31 obese subjects (22 male and 19 female) with the inclusion criteria whose body mass index and age was 36.46 ± 2.22 and 38.48 ± 2.27, respectively. This Ketogenic diet was called "Spanish Ketogenic Mediterranean Diet" (SKMD) due to the incorporation of virgin olive oil as the principal source of fat (≥30 ml/day), moderate red wine intake (200–400 ml/day), green vegetables and salads as the main source of carbohydrates and fish as the main source of proteins. It was an unlimited calorie diet. Statistical differences between the parameters studied before and after the administration of the "Spanish Ketogenic Mediterranean diet" (week 0 and 12) were analyzed by paired Student's <it>t </it>test.</p> <p>Results</p> <p>There was an extremely significant (p < 0.0001) reduction in body weight (108.62 kg→ 94.48 kg), body mass index (36.46 kg/m²→31.76 kg/m²), systolic blood pressure (125.71 mmHg→109.05 mmHg), diastolic blood pressure (84.52 mmHg→ 75.24 mmHg), total cholesterol (208.24 mg/dl→186.62 mg/dl), triacylglicerols (218.67 mg/dl→113.90 mg/dl) and glucose (109.81 mg/dl→ 93.33 mg/dl). There was a significant (p = 0.0167) reduction in LDLc (114.52 mg/dl→105.95 mg/dl) and an extremely significant increase in HDLc (50.10 mg/dl→54.57 mg/dl). The most affected parameter was the triacylglicerols (47.91% of reduction).</p> <p>Conclusion</p> <p>The SKMD is safe, an effective way of losing weight, promoting non-atherogenic lipid profiles, lowering blood pressure and improving fasting blood glucose levels. Future research should include a larger sample size, a longer term use and a comparison with other ketogenic diets.</p

Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study

<p>Abstract</p> <p>Background</p> <p>Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM) competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (T_max range: 32°C to 40°C); simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques.</p> <p>Methods</p> <p>Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, <it>n</it> = 74) and control (CON, <it>n</it> = 12) through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM), hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5.</p> <p>Results</p> <p>Water (overall mean (SD): total daily 7.7 (1.5) L/day, during running 732 (183) ml/h) and sodium (total daily 3.9 (1.3) g/day, during running 270 (151) mg/L) ingestion did not differ between stages in UER (<it>p</it> < 0.001 <it>vs</it>. CON). Exercise-induced BM loss was 2.4 (1.2)% (<it>p</it> < 0.001). Pre- to post-stage BM gains were observed in 26% of UER along competition. Pre- and post-stage plasma osmolality remained within normal clinical reference range (280 to 303 mOsmol/kg) in the majority of UER (<it>p</it> > 0.05 <it>vs</it>. CON pre-stage). Asymptomatic hyponatraemia (<135 mmol/L) was evident pre- and post-stage in <it>n</it> = 8 UER, corresponding to 42% of sampled participants. Pre- and post-stage urine colour, urine osmolality and urine/plasma osmolality ratio increased (<it>p</it> < 0.001) as competition progressed in UER, with no change in CON. Plasma volume and extra-cellular water increased (<it>p</it> < 0.001) 22.8% and 9.2%, respectively, from pre-Stage 1 to 5 in UER, with no change in CON.</p> <p>Conclusion</p> <p>Water intake habits of ultra-runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition, irrespective of running speed and gender. Normonatraemia was observed in the majority of ultra-runners throughout MSUM, despite sodium ingestion under benchmark recommendations.</p

Psychological determinants of whole-body endurance performance

Background: No literature reviews have systematically identified and evaluated research on the psychological determinants of endurance performance, and sport psychology performance-enhancement guidelines for endurance sports are not founded on a systematic appraisal of endurance-specific research. Objective: A systematic literature review was conducted to identify practical psychological interventions that improve endurance performance and to identify additional psychological factors that affect endurance performance. Additional objectives were to evaluate the research practices of included studies, to suggest theoretical and applied implications, and to guide future research. Methods: Electronic databases, forward-citation searches, and manual searches of reference lists were used to locate relevant studies. Peer-reviewed studies were included when they chose an experimental or quasi-experimental research design, a psychological manipulation, endurance performance as the dependent variable, and athletes or physically-active, healthy adults as participants. Results: Consistent support was found for using imagery, self-talk, and goal setting to improve endurance performance, but it is unclear whether learning multiple psychological skills is more beneficial than learning one psychological skill. The results also demonstrated that mental fatigue undermines endurance performance, and verbal encouragement and head-to-head competition can have a beneficial effect. Interventions that influenced perception of effort consistently affected endurance performance. Conclusions: Psychological skills training could benefit an endurance athlete. Researchers are encouraged to compare different practical psychological interventions, to examine the effects of these interventions for athletes in competition, and to include a placebo control condition or an alternative control treatment. Researchers are also encouraged to explore additional psychological factors that could have a negative effect on endurance performance. Future research should include psychological mediating variables and moderating variables. Implications for theoretical explanations of endurance performance and evidence-based practice are described

Balance in single-limb stance in healthy subjects – reliability of testing procedure and the effect of short-duration sub-maximal cycling

BACKGROUND: To assess balance in single-limb stance, center of pressure movements can be registered by stabilometry with force platforms. This can be used for evaluation of injuries to the lower extremities. It is important to ensure that the assessment tools we use in the clinical setting and in research have minimal measurement error. Previous studies have shown that the ability to maintain standing balance is decreased by fatiguing exercise. There is, however, a need for further studies regarding possible effects of general exercise on balance in single-limb stance. The aims of this study were: 1) to assess the test-retest reliability of balance variables measured in single-limb stance on a force platform, and 2) to study the effect of exercise on balance in single-limb stance, in healthy subjects. METHODS: Forty-two individuals were examined for test-retest reliability, and 24 individuals were tested before (pre-exercise) and after (post-exercise) short-duration, sub-maximal cycling. Amplitude and average speed of center of pressure movements were registered in the frontal and sagittal planes. Mean difference between test and retest with 95% confidence interval, the intraclass correlation coefficient, and the Bland and Altman graphs with limits of agreement, were used as statistical methods for assessing test-retest reliability. The paired t-test was used for comparisons between pre- and post-exercise measurements. RESULTS: No difference was found between test and retest. The intraclass correlation coefficients ranged from 0.79 to 0.95 in all stabilometric variables except one. The limits of agreement revealed that small changes in an individual's performance cannot be detected. Higher values were found after cycling in three of the eight stabilometric variables. CONCLUSIONS: The absence of systematic variation and the high ICC values, indicate that the test is reliable for distinguishing among groups of subjects. However, relatively large differences in an individual's balance performance would be required to confidently state that a change is real. The higher values found after cycling, indicate compensatory mechanisms intended to maintain balance, or a decreased ability to maintain balance. It is recommended that average speed and DEV 10; the variables showing the best reliability and effects of exercise, be used in future studies

Neuromuscular Consequences of an Extreme Mountain Ultra-Marathon

We investigated the physiological consequences of one of the most extreme exercises realized by humans in race conditions: a 166-km mountain ultra-marathon (MUM) with 9500 m of positive and negative elevation change. For this purpose, (i) the fatigue induced by the MUM and (ii) the recovery processes over two weeks were assessed. Evaluation of neuromuscular function (NMF) and blood markers of muscle damage and inflammation were performed before and immediately following (n = 22), and 2, 5, 9 and 16 days after the MUM (n = 11) in experienced ultra-marathon runners. Large maximal voluntary contraction decreases occurred after MUM (−35% [95% CI: −28 to −42%] and −39% [95% CI: −32 to −46%] for KE and PF, respectively), with alteration of maximal voluntary activation, mainly for KE (−19% [95% CI: −7 to −32%]). Significant modifications in markers of muscle damage and inflammation were observed after the MUM as suggested by the large changes in creatine kinase (from 144±94 to 13,633±12,626 UI L−1), myoglobin (from 32±22 to 1,432±1,209 µg L−1), and C-Reactive Protein (from <2.0 to 37.7±26.5 mg L−1). Moderate to large reductions in maximal compound muscle action potential amplitude, high-frequency doublet force, and low frequency fatigue (index of excitation-contraction coupling alteration) were also observed for both muscle groups. Sixteen days after MUM, NMF had returned to initial values, with most of the recovery process occurring within 9 days of the race. These findings suggest that the large alterations in NMF after an ultra-marathon race are multi-factorial, including failure of excitation-contraction coupling, which has never been described after prolonged running. It is also concluded that as early as two weeks after such an extreme running exercise, maximal force capacities have returned to baseline