Hydration
D E H Y D R AT I O N I T S E F F E C T S
AND H OW TO P R E V E NT IT
Dehydration
•
During winter sports, an athlete does not have a sense of thirst which can cause problems that lead to dehydration
(Kenefick et. al, 2004
•
Winter sport participants do not voluntarily match their fluid intake during exercise with their fluid losses and thus
become moderately (2-3%) to substantially (>4%) dehydrated Noakes, 1993 and Mars et al 2014 - In football, hockey
and rugby etc athletes rehydrate at specific stoppages (and are encouraged to drink by a coach/trainer). This does
not happen in winter sports. Solution drink at the start/end of every run or very 30mins
•
2% drop in body mass due to dehydration can impair physical performance by 20%. Peronnet 2010
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Dehydration can lead to a reduced cardiovascular efficiency extended energy requirements, and a decrease in
muscle blood flow Seifert et. al., 2006 - This can make skiing physically harder and decrease your enjoyment
•
Decreased neuromuscular ability Kleiner, 1999 (balance and body control are effected by dehydration and
potentially increase risk of injury)
•
A 1-4% change in body weight due to dehydration has shown cognitive function decrease Cain et al., 2000 (Memory,
judgement of distance and rapid decision are effected, not what you want when skiing at speed)
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Skill based performance is similarly effected by dehydration - accuracy of tasks done at speed, body control,
positional awareness have been show to be severely negatively effected with moderate dehydration
•
The time to exhaustion is significantly shorter in cold climates and with dehydration (Sandsund er. al., 1998).
Optimally hydrated skiers have had up to 25% longer time to exhaustion and less fatigue the following day
•
Hyperthermia and clod sensation has been shown to come on sooner in dehydrated persons
•
Respiratory water loss at altitude may be twice as high as at sea level; theoretical calculations for 24-h respiratory
water loss approach 1 L day in addition to fluids lost through sweat and urine (Milledge, 1992).
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Respiratory (breathing) water loss can be as high as 1.9 L day in men (Butterfield et al., 1992) and 850 mL day in
women (Mawson et al., 2000). - h
•
During exercise in cold environments, individuals often lose 3–8% of their body weight. Reasons for this include large
sweat losses, respiratory water loss, impaired thirst, and limited access to fluids Freund & Sawka, 1996
Seifert et al 2006 Use a back mounted hydration pack (camel backs)
•
Percent change in blood plasma volume was less
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urine osmolality was maintained in the BMHS
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Body mass loss was minimized
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Skiers reported that they felt significantly better when they ingested water during the BMHS trials. In conclusion, a back-mounted hydration system allowed the skiers to
maintain hydration status
Seifert et al 2012 Effect of carbohydrate-protein gel on Alpine Ski Performance
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Carbohydrate-protein energy gel (GEL) improves finishing success and number of gates completed during 2 hr slalom sessions on two consecutive days of training
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Gel was Carbohydrate 20g, protein 5g, and 150 mL H20
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50% less did not finishes (DNF) were seen with the athletes taking a gell
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10% greater number of training gates day two
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RPE fatigue preception) was reported to be lower in the Gel group
Physical Signs of
Dehydration
Check your Pee!!
1
2
3
4
1 -3: You are hydrated
Negative Effects on Skiing
4-6: Mild to moderately dehydrated and this can imped your ski
performance
5
7-9: You are dehydrated
6
To avoid dehydration, consume water and/or sports drinks
before, during and after workouts
7
8
9
Certain foods, medicines and vitamins consumed in large
amounts, may cause the colour of urine to change rendering the
chart unreliable.
Monitoring Hydration
Weight in the morning (in underwear and
after being to the toilet)
Weight after skiing (in underwear )
Approximately rehydrate with ½ liter of water
per 500grams lost
Or use this calculator Click
Hydration Planning For Skiing
Timing
Amount
Method
1-2 Hours Pre-Exercise
0.5 liter
H20
Immediately Before
250 ml
H20 or Sport Drink (6%
carbohydrate)
1st Hour Training @ 2030 mins Intervals
250 ml
H20
2nd Hr+ Training @
30mins intervals
250 ml
• Alternate H20/Sport Drink
(6% carbohydrate)
• Sports drink contains
electrolytes lost with sweat
(not redbull, monster etc)
• Gel (performance
enhancer) Carbohydrate
20g, protein 5g, and 150 mL
H20
½ litre for every 0.5kg
lost
• Mixed (does not include
caffeinated beverages,
alcohol)
• Protein shake with skimmed
milk post training
Post Exercise Weight in
vs Weight Out
Hydration
Protocol