A.2.1SL only
Water and electrolyte balance
Guiding question: Why does an athlete need the right balance of water and salts, and how can they tell if it is wrong?
Learn it, then try it
Read each idea, work through its activities, then tick it off. 0 of 1 done.
A.2.1.1
Water and electrolyte balance
Water and electrolytes are absorbed from the intestines and lost in sweat, breath and urine. If balance is lost, dehydration, hypernatraemia or hyponatraemia can result, harming both health and performance. Status can be checked with body mass change, urine colour and urine osmolarity. Osmoreceptors in the hypothalamus detect changes, and the pituitary releases ADH, which makes the kidneys retain water. In prolonged steady exercise, fluid loss and rising core temperature cause cardiovascular drift.
Match the terms
Key terms
Match each term to its meaning.
Tap a term, then tap its meaning.
Check yourself
Quick check
1.Which statement describes electrolytes?
2.During exercise, through which routes is fluid lost by evaporation? I. The skin II. The respiratory tract III. The urine
3.A slow marathon runner drinks large volumes of plain water during the race. At the finish she is confused and nauseous, and her blood sodium concentration is 128 mmol/L. Which condition is most likely?