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Nathan Goodyear

Exercise-induced right ventricular dysfunction and structural remodelling in endurance ... - 0 views

  • In a cohort of well-trained athletes, we demonstrated that intense endurance exercise causes an acute reduction in RV function that increases with race duration and correlates with increases in biomarkers of myocardial injury
  • no relationship between LV function and biomarker levels
  • focal gadolinium enhancement and increased RV remodelling were more prevalent in those athletes with a longer history of competitive sport, suggesting that repetitive ultra-endurance exercise may lead to more extensive RV change and possible myocardial fibrosis
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  • he cardiac impact of both acute and cumulative exercise is greatest on the RV.
  • Greater reductions in RV function occurred in those athletes competing for a longer duration, suggesting that the heart has a finite capacity to maintain the increased work demands of exercise
  • cardiac injury is greatest in the least trained
  • Previous investigators have documented reductions in RV function in less trained subjects over the marathon distance
  • We enrolled elite and subelite athletes and found a significant association between fitness (VO2max) and the reduction in post-race RVEF
  • Even after many years of detraining, cardiac dilation may not completely regress in elite athletes
  • The focus on well-trained athletes may be of particular relevance, given that they perform exercise of highest intensity and duration most frequently, and, thus, may be at a greater risk of cumulative injury.
  • The lack of correlation between increases in troponin and changes in LV function seen in this study has been previously interpreted as evidence that post-exercise elevations in cardiac biomarkers are benign.
  • a significant correlation between changes in RVEF and post-race biomarker levels and this relationship was even stronger in the athletes who completed the race of longest duration, the ultra-triathlon
  • The correlations with RVEF, but not LVEF, provide further evidence of the differential effects of intense exercise on RV and LV function
  • BNP release during intense exercise is associated with greater relative increases in RV systolic pressures, but not LV pressures
  • BNP may provide a measure of both acute RV load and the resultant fatigue which occurs when this load is sustained
  • It has been demonstrated that ventricular load increases with exercise intensity and is greater for the RV than the LV,29 thus potentially explaining why the RV is more susceptible to fatigue after prolonged exercise.
  • This study demonstrates, for the first time, an association between endurance exercise of increasing duration and structural, functional, and biochemical markers of cardiac dysfunction in highly trained athletes
  • Functional abnormalities were confined to the RV and were largely reversible 1 week following the event
  • there remained a significant minority of athletes in whom there was evidence of myocardial fibrosis in the interventricular septum
  • RV abnormalities may be acquired through cumulative bouts of intense exercise and provides direction for prospective investigations aimed at elucidating whether extreme exercise may promote arrhythmias in some athletes.
  • the acute injury and chronic remodelling of the myocardium both disproportionately affect the RV and it remains possible that the two are linked.
  • focal DGE was confined to the interventricular septum and commonly at the site of RV attachment
  • emerging evidence that intense endurance exercise may be associated with an excess in arrhythmic disorders, the mechanisms for which remain unexplained
  • RVEF (and not LVEF) was reduced in athletes with complex ventricular arrhythmias when compared with healthy athletes and non-athletes without arrhythmias
  • it is premature to conclude that these changes may represent a proarrhythmic substrate
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    Study finds endurance racing results in reduce Right ventricle ejection fraction even in elite athletes.  This post-race RVEF reduction is associated with VO2max.
Nathan Goodyear

Metabolic characteristics of keto-adapted ultra-endurance runners - Metabolism - Clinic... - 0 views

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    full study of previous abstract: low carb and high fat diet found to maintain muscle glycogen equal to high carb diet in endurance athletes.  Endurance athletes have high fat oxidation and this probably only applies to these endurance athletes; I would suspect this high fat oxidation would not be found in other short interval sports i.e. sprinting, football....
Nathan Goodyear

Intravenous Fluid Use in Athletes - 0 views

  • Treatment of exercise-associated hyponatremia with hypertonic IV infusion to correct plasma sodium levels is also a standard and accepted use of IV fluid infusions
  • athletes who present for medical care with hypernatremia who cannot tolerate oral fluids can benefit from IV fluids
  • Vaporization of sweat accounts for 80% of heat loss in hot, dry atmospheric conditions. This mechanism of water loss is the major contributor for exercise-associated dehydration
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  • The rate of water loss can be quantified through measurement of sweat rate
  • Pre- and postexercise body weight measurements are the most common means to estimate overall water loss but are condition specific
  • It appears that 1% to 2% body weight loss is well tolerated by the exercising athlete
  • Dehydration, defined as greater than 2% loss of body weight, can negatively affect performance
  • In highly trained endurance athletes, plasma volume and sodium serum concentration were preserved despite a 5% body weight loss
  • In Ironman triathletes, dehydration to 5% body weight loss did not correlate with occurrence of medical complications
  • hydration should begin hours prior to exercise, especially if known deficits are present, and fluids should be consumed at a slow, steady rate, with 5 to 7 mL/kg taken 4 hours prior to exercise
  • Sodium concentration did not produce significant changes in the rate of absorption but was primarily dependent on carbohydrate concentration
  • Replacing 150% of body weight loss over 60 minutes has been tolerated without complications
  • IV treatment of severe dehydration (>7% body weight loss), exertional heat illness, nausea, emesis, or diarrhea, and in those who cannot ingest oral fluids for other reasons, is clinically indicated
  • A recent survey of the National Football League teams revealed that 75% (24 of 32) of the teams utilized IV infusion of fluids for prehydration in at least some otherwise healthy individuals
  • In the National Football League, an average of 1.5 L of normal saline was administered approximately 2.5 hours prior to competition
  • after 2 hours of exercise, the rectal temperature was 0.6° higher in the group not receiving IV infusion. Also, stroke volume and cardiac output were 11% to 16% lower in the control group versus the IV infusion group.
  • Recent evidence suggests the etiology of EAMC is related to muscle fatigue and neuronal excitability
  • no correlation between hydration status or electrolyte concentrations with EAMC
  • there may be a subset of muscle cramping that is associated with a loss of both body fluid and sodium
  • Glycerol is the primary agent for oral hyperhydration
  • elevation of plasma volume by 200 to 300 mL via dextran infusion resulted in 15% increase in stroke volume, 4% increase in VO2 max, and an increase in the exercise time to fatigue
  • Neither the tonicity nor mode of hydration resulted in improved speed of rehydration, greater fluid retention, or improved performance
  • There are beneficial anecdotal reports of EAMC treatment in elite and professional-level athletes with IV hydration during the course of an event
  • Plasma volume was better restored during rehydration with IV fluids at preexercise and 5 minutes of exercise. At 15 minutes, there was no difference between IV and oral rehydration
  • More rapid restoration of plasma volume was accomplished in the IV treatment group with no advantages over oral rehydration in physiological strain, heat tolerance, ratings of perceived effort, or thermal sensations
  • No difference was found in exercise time to exhaustion. IV and oral rehydration methods were equally effective. Heart rates were statistically higher in the oral rehydration group through 75 minutes of exercise, and there were higher increases in norepinephrine plasma concentrations
  • No significant differences between the groups were found for time to recovery, number of days with pain, number of days with stiffness, sleep disturbance, fatigue, rectal temperature, and loss of appetite
  • The current data suggest that IV rehydration is faster than oral
  • There may be physiological benefits of decreased heart rate and norepinephrine in athletes rehydrated via IV route
  • Postexercise blood 1 hour and 24 hours showed no differences in circulating myoglobin or creatine kinase
  • The use of IV fluid may be beneficial for a subset of fluid sensitive athletes
  • this should be reserved for high-level athletes with strong histories of symptoms in well-monitored settings.
  • Volume expanders may also be beneficial for some athletes
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    to be read
Nathan Goodyear

Omega-3 fatty acids supplementation improves endothelial function and maximal oxygen up... - 0 views

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    supplementation of 2.6 grams of n-3 found to increase NO and VO2max in elite cycling athletes.  This has applications for all endurance athletes.  
Nathan Goodyear

The human metabolic response to chronic ketosis without caloric restriction: preservati... - 0 views

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    ketogenic diet found to not deplete muscle glycogen in endurance athletes.  The metabolism of the endurance athletes can do this via the high fat oxidation--estimates of 80%.
Nathan Goodyear

https://www.cayugamed.org/docs/Nutrition_Update_for_the_Ultraendurance_Athlete%208.pdf - 0 views

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    Nutrition for ultra endurance.  To be read.
Nathan Goodyear

Metabolic characteristics of keto-adapted ultra-endurance runners - Metabolism - Clinic... - 0 views

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    For endurance athletes, low carb and high fat diet utilizes the high fat oxidation in these athletes compared to a high carb diet.  Glycogen stores did not differ between the two groups.  
Nathan Goodyear

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1332190/pdf/brjsmed00019-0063.pdf - 0 views

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    study finds IV hydration with glucose and larger volume did not recover as well as those with 100 ml  of IV fluids.  This conclusion is incomplete as the time differences between the 2 groups was significant--group 2 (2.5 L fluid group) finished much faster and studies have shown that these endurance athletes are more prone to dehydration, more significant weight loss, adverse effects from the event.  This likely explains the difference between the 2 groups.
Nathan Goodyear

The endurance athletes heart: acute stress and chronic adaptation -- George et al. 46 (... - 0 views

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    acute and chronic heart changes to endurance training/events.
Nathan Goodyear

Diagnosis and prevention of hyponatremia at an ultradistance triath... - PubMed - NCBI - 0 views

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    over hydration increases risk of hyponatremia.  Body weight is inversely associated with Na levels.  Weight evaluations are an appropriate means to evaluate.  Endurance triathlon athletes can lose up to 5% without any negative physiologic impact.
Nathan Goodyear

The effect of strength training on performance in endurance athletes. - PubMed - NCBI - 0 views

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    strength training improved performance of endurance athletes.  This study is a meta-analysis.
Nathan Goodyear

Fluid Balance During and After an Ironman Triathlon - ResearchGate - 0 views

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    ultra distance triathlon athletes lost 2.5 kg weight during event.  Athletes that developed hyponatremia appeared to be fluid overloaded during event.
Nathan Goodyear

Exercise-Associated Muscle Cramps - 0 views

  • athletes who develop EAMC often ingest similar amounts of fluid during exercise as do their noncramping counterparts
  • Oral fluid ingestion may be ineffective, and intravenous fluid may provide a faster delivery for athletes suffering from acute EAMC
  • It is interesting that stretching the affected muscle almost immediately relieves EAMC
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  • Stretching, the primary treatment for acute EAMC
  • National Athletic Trainers’ Association recommends that athletes prone to muscle cramping add 0.3 to 0.7 g/L of salt to their drinks to stave off muscle cramps
  • Others have recommended adding higher amounts of sodium (about 3.0 to 6.0 g/L) to sports drinks based on the frequency of EAMC
  • intravenous infusion of fluids removes this delay, and it has been used to aid athletes who develop acute EAMC
  • maintaining hydration and adequate electrolyte levels is a good prevention strategy for individuals susceptible to EAMC
  • Fluid volumes of 1.8 L per hour have been well tolerated by tennis athletes who are susceptible to EAMC
  • Monitoring an athlete’s body weight is an easy method of ensuring adequate fluid replacement and individualizes each athlete’s fluid needs
  • the National Athletic Trainers’ Association and the American College of Sports Medicine recommend a volume of fluid that allows for less than a 2% body weight reduction
  • Endurance training may also serve as an effective means of preventing EAMC by expanding plasma volume and the extracellular fluid compartment15 and delaying neuromuscular fatigue
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    Exercise associated muscle cramps or EAMC is not worked out.  The theories include dehydration, mineral/electrolyte deficiencies, and neuromuscular activity.
Nathan Goodyear

Thieme E-Journals - International Journal of Sports Medicine / Abstract - 0 views

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    Ultra endurance athletic events associated with significant increase in systemic inflammation due to damaged gut.
Nathan Goodyear

A Low Carbohydrate-Protein Supplement Improves Endurance Per... : The Journal of Streng... - 0 views

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    protein:low carb supplement improves athletic endurance over that of 6% carb alone
Nathan Goodyear

http://www.sportsperformancecentres.com/articles/interest/Endurance_Exercise_and_Protei... - 0 views

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    white paper on protein for endurance athletes.
Nathan Goodyear

Exercise-induced right ventricular dysfunction and structural remodelling in endurance ... - 0 views

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    endurance training found to induce heart dysfunction.  This was all in the right ventricular function, but significant dysfunction was found.
Nathan Goodyear

Exercise-associated hyponatremia: role of cytokines. - PubMed - NCBI - 0 views

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    study links rhabdomyolysis to exercise induced hyponatremia.  This article links the depletion of glycogen to muscle release of IL-6 leading to increase in ECW and thus hyponatremia. The abstract discusses fluid restriction vs hypertonic 3% NaCL to reverse the more severe cases.  The first signs are of weight gain and thus weight should be monitored.  Decreased renal output is also associated with EAH.  Altered mental status is an early sign.
Nathan Goodyear

Idiopathic hypogonadotropic hypogonadism in a ... [Fertil Steril. 1997] - PubMed - NCBI - 0 views

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    Case study finds clomid restores HPA function and normalizes Testosterone production in HPA suppressed endurance athlete.
Nathan Goodyear

http://www.msma.org/docs/communications/momed/Excessive_Endurance_Exercise_and_Heart_Di... - 0 views

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    great review of data on cardiac damage associated with extreme endurance training.  These EEEs, that they are called, are rare in those < 40 and usually involved genetic defects.  This article points to aggressive preventive testing in those > 50.
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