Eating Enough to Run?
Low energy availability for performance is something that many athletes may suffer from. It may be as a result of trying to lose a little weight or trying to maintain a low weight for your sport. It may happen consciously or it may be that an athlete’s slips into this state without an understanding of what is occurring.
In this episode we are going to delve into the health and performance consequences of low energy availability before giving you some ideas of how to seek help and support if required and some hints and tips on how to avoid slipping into this scenario.
SHOW NOTES
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Why is it important to discuss this topic?
Well, The short answer is because appropriate energy availability is essential for attaining and also maintaining exercise performance. But to expand on that: energy availability is dependent on energy intake from the diet matching the energy expenditure of exercise, where the energy expenditure of exercise is calculated as the energy expended, above that required for daily living. BUT for many runners (and other athletes) there is a mismatch between the two, leaving inadequate energy to support the normal functions of the body and exercise performance.
Optimal energy availability for the healthy physiological functioning of the body is typically achieved at an energy availability of 45 calories per KG of free fat mass per day. Free fat mass is used as a measure because it is a good reflection of the body's most metabolically active tissue.
(12:50)
The health effects of low energy availability (LEA) include:
Endocrine disruption –It is thought that hormones become disrupted in an effort to conserve energy for the most important bodily functions and processes.
Sex Hormone disruption –especially a decrease of oestrogen and progesterone production in women and testosterone in men potentially leading to fertility issues.
Menstrual dysfunction – Low Energy Availability is thought to affect Gonadotropin Releasing Hormone pulsitility within the Hypothalamus, which then leads to the disruption to Leutinising Hormone and Follicle Stimulating Hormone, and oestrogen/progesterone,
Impaired bone health – generally linked to amenorrhoea (loss of periods) and affects BMD, bone turnover, bone strength and an increased risk of stress fracture.
Reduced Resting Metabolic Rate - as a result of reduced T3 thyroid hormone production. Appears to be really prevalent in endurance athletes.
Impaired blood cell formation and turnover (haematopoiesis) – this appears to be linked to low iron availability as a result of Low Energy Availability.
Compromised immune function – leading to increased risk of infection (such as URTI), inflammation, injury as well as GI symptoms.
Impaired cardiovascular health – low oestrogen levels are associated with atherosclerosis and poor lipid status ie DHL/LDL levels. But severe Low Energy Availability (LEA) and Eating Disorders (ED) may lead to significant Cardiovascular changes including: irregular heart beat and hypotension
Gastrointestinal dysfunction – including altered sphincter function, delayed gastric emptying, constipation and increased intestinal transit time
Compromised muscle function – a daily protein intake of less than 30Kcal per Kg of free fat mass is known to reduce muscle synthesis
Psychological issues - are closely linked to LEA and these issues may precede or be caused by LEA. A higher drive for thinness, which is associated with DE/ED is one of the known leading triggers of LEA.
(22:56)
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