Hydration

I am about to do The James Pony Express! It’s a 65km mountain bike race, the organisers sent us a email about Hydration. It is a pretty interesting read so I am sharing it on Elite6 for all the fitness junkies.

COURSE NOTES:

While this race is relatively shorter than the Epic option, riders should still have a reasonable standard of fitness and be comfortable crossing rivers with their bikes.

Average time: Womens 5:08:33, Mens 4:49:06, overall 4:52:29. Average expected finish time – 2:30pm, earliest finish expected 12:30 pm.

Hydration Excerpt from Mountain Biking Australia Magazine article

Written by Emily Miazga, M.Sc. Clinical Nutrition, 3x Coast to Coast Champ and Creator of Em’s Power Cookies

Pre-Hydration

Pre-hydrate ahead of time for a few days. Water is fine but you can also use a sports drink with a good sodium content of at least 500mg/L especially for the 1-2 days before an event because the extra carbohydrate for carb-loading comes in handy.

The recommendation for pre-hydration is 6ml water per kg of body weight every 2-3 hours

For the average person this will equate to an extra 2.5-3L fluid per day leading up to an event.

Hydration During

The normal rate of sweating is about 1.0 – 1.5L/hour during harder exercise but some can sweat as much as 2.5L so individual fluid requirements vary. Different things affect the sweat rate such as metabolic rate, the environmental conditions and how well you’re acclimatised. I always recommend using a good sports drink with sodium because that is the main electrolyte lost through sweating. The risk of cramping will be minimised as well by ensuring enough sodium is consumed. For those who are more prone to cramping you can increase the sodium up to 1500mg/L. So for a standard sports drink that contains approximately 500mg/L, you can add another 1/3 to ½ tsp. of salt to the mix. One teaspoon of salt contains 2400mg of sodium.

For during exercise over 1 hour in the heat aim for 250-300mL every 15 minutes, and use a sports drink containing 500-700mg sodium per L. Individual needs vary

If you are a heavy sweater, you need to consume more, and if prone to cramping add some salt as per the above. Don’t forget about carbohydrate needs. The target is 30-60g carbohydrate/hour for anything between 1-2.5 hours. If longer than 2.5hours then aim for up to 90g carb/hour. Remember the carbs in your sports drink count towards the carb tally.

Post-Rehydration

After a session in the heat, even if you’ve been drinking during you still need to rehydrate afterwards because this will help your recovery and you need to replace the fluids lost. In order to determine how much you lost, simply weigh yourself before and after and that will be your body mass loss.

The recommendation is to consume 150% of your body mass loss within 1 hour

So if you lost 1 kg, the target would be 1.5L, but this might be hard to get in so a more realistic target is 100-120% of body mass loss. The best way to recover is to have a mix of fluids and salty foods so you are getting in carbs and protein too.

External and Internal Cooling Methods

In addition to acclimatising and hydrating, you can take things a step further by using cold water immersion, ice-garments or cold wet towels to pre-cool before heading out. More practically, having a cold drink or ice-slurry before exercise has a beneficial pre-cooling effect that can help performance, and cold drinks can also be used during your ride to help stay cool.

Towelling off wet skin and fanning is quick, easy and practical particularly if riding on a lap course. And you have a pit stop where you can implement some if these ideas, have your support crew with a chilly bin containing cold drinks, cold towels, etc. to help cool off.