water for exercise performance

Question 1

above what level of dehydration is a decline in aerobic performance seen

Answer 1

> 2%

Question 2

what are the two types of exercise hypohydration

Answer 2

pre-exisiting hypohydration

exercise induced hypohydration

Question 3

why is the performance decline associated with hypohydration more pronounced at higher temperatures

Answer 3

higher temperature = greater demand of blood supply to the skin

this reduces muscle and cerebral blood supply

there is also more heat which puts more demand on thermoregulation systems

Question 4

what effect has hypohydration been shown to have on strength performance

Answer 4

decrease in maximum voluntary contraction

decrease resistance exercise performance
(less amount of work done each set so therefore likely to do less overall work and so not adapt as much)

Question 5

why does sweating a lot lead to increased plasma osmolality

Answer 5

sweat is hypotonic to blood

so hypohydration due to sweating will result in a higher plasma osmolality

Question 6

give three reasons why hypohydration results in impaired temperature control

Answer 6

increased heat storage

relatively lower blood flow to skin

relatively lower sweat rate

Question 7

why does relative exercise intensity increase with hypohydration

Answer 7

unable to sustain cardiac output

reduction in maximum aerobic power

Question 8

Give reasons why Na+ should be included in drinks

Answer 8

prevents development of hyponatraemia if over drink after exercise

can help retain water which is consumed before exercise

will be needed if exercise if > 2hours bc will be significant loss