Is better hydration the secret to improving my running performance?

For most of us, the answer is a resounding yes. 

[EDIT 2019: current research shows loss of body weight is not a great measure of dehydration and it’s effect on your performance]

A conversation with a client the other night prompted me to analyse my own fluid intake during races. It was surprisingly little, even though I’m well aware of the value of hydrating. It’s interesting how you can overlook the little things.

Dehydration resulting in a loss of just 1% of your body weight can cause a loss in performance. Levels of up to 3% are quite common in sports of around 1 hour duration, and you can reach this level quite quickly if you go into an event under hydrated. Studies have shown when dehydration causes a 3-5% loss in body weight, work capacity decreases by as much as 35-48%. One of our runners weighed in before and after the SMH half marathon to find she’d had a 2% loss of body weight-probably more as she was weighed in the clothes she ran in, which would have retained some of her sweat, therefore weighing more.

To find out how much fluid you lose during an exercise session you need to weigh yourself naked before and after the session, or if not naked, in the same dry clothes before and after.  Weighing yourself before you exercise, then weighing yourself afterwards in the same clothes will give you a false reading, as the clothes you run in will most likely retain some of your sweat, giving you a heavier reading. Take the difference of your pre-exercise and post exercise weights, then add 100 gms for every 100mls of fluid taken in whilst exercising. This will give you the amount of fluid you have lost during exercise. Each kg of weight lost represents 1 litre of fluid lost. You should measure this long term, and take note of temperature and humidity as well as exercise intensity, and use it to predict how much fluid you should take in during the course of an exercise session.

How do I know if I am  dehydrated?

If you’ve lost more than 2% of your body weight using the method above, you’ve definitely moved into a dehydrated state, and remember just a 1% loss of body weight can cause a loss in performance. Other signs and symptoms include

  • Thirst/dry mouth
  • Headache
  • Dizziness
  • Nausea
  • Fatigue and tiredness. Literally feeling like you could just stop running and go to sleep.

Other more serious signs and symptoms include vomiting, tingling of the limbs, muscle cramps, difficulty breathing and death.

Most if not all of these could be put down to something else, but if you get a few of the symptoms, it’s worthwhile doing an analysis of your fluid intake during a race. Think about how much you drink prior to the race as well as during. You’d be lucky to take in 150mls from each of those little plastic cups you scoop up at the water stations (I have just measured one about 3/4 full).

How much fluid should I take in to perform at my peak?

This depends on a number of factors. To get a true idea of how much fluid you should take in during a race, you need to go through the pre and post workout weighing procedure over a period of time to predict how much fluid you are going to lose, given a certain set of circumstances. Things that effect your dehydration rate include:

  • temperature and humidity
  • exercise intensity
  • how used you are to the conditions
  • clothing
  • baseline hydration status
  • individual differences

Pre-race hydration

You should go into an event well hydrated. The colour of your urine is a good indication of your hydration status. If it’s clear, you’re well hydrated. If it’s like tea, then start drinking. For a week or so prior to your event, be very conscious of the colour of your urine, and adjust your fluid intake accordingly.

Fluids on the day

Keep in mind that each person’s needs will be different, but as a rule of thumb you should go for:

  • 500-600mls of water of sports drink 2-3 hrs before the start. In reality, this means having about a glass and a half of water when you get up. This will give your body time to pass any excess water out of your system before the race.
  • 200-300mls 10-20 minutes before the race
  • 200-300 mls every 10-20 minutes to maintain fluid loss at less than 2%

If you don’t normally drink before the race, be a little cautious about going all out on these recommendations first up, but you should be working towards around about these amounts over a period of time. Practice on your long runs first, then try it in a race.

If you don’t normally grab a drink at every stop, do so. Even if you just take a couple of mouthfuls each water station, that will help, but taking in a couple of cups would be better.

If you’re a bit scared of changing what you consider to be a proven formula, even if on analysis you realise you’re not taking in nearly as much water as indicated above, at least make sure you go into race day well hydrated. Do the wee test. Make sure you drink enough water for your urine to be running clear the day before the race. Even if you do nothing else, you will most likely see an improvement in your performance through this alone.

Reference: National Athletic Trainers’ Association Position Statement: Fluid Replacement for Athletes J Athl Train. 2000 Apr-Jun; 35(2): 212–224.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1323420/ sited June 24th 2013
 Image courtesy of Marcus / FreeDigitalPhotos.net

 

DISCLAIMER: Any information contained in this document is obtained from current and reliable sources and is solely for the purpose of interest and information.  Individuals receiving this information must exercise their independent judgment in determining its appropriateness for their particular needs. The information and training advice is general in nature and may not be suited to the recipient’s individual needs. Medical advice should always be sought when starting an exercise program. As the ordinary or otherwise use(s) of this information is outside the control of the author, no representation or warranty, expressed or implied, is made as to the effect(s) of such use(s), (including damage or injury), or the results obtained. The author expressly disclaims responsibility as to the interpretation of the views contained in this article, ordinary or otherwise. Furthermore, the author shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. The author shall not be responsible for any damages resulting from use of or reliance upon this information. Readers of this document are solely responsible for compliance with all laws and regulations applying to the use of the information, including intellectual property rights of third parties.

 

Top Ten Fat Blasters

fat blasting exercisesHere are 10 essential things you need to know if you are exercising for fat loss.

 

1. Burn Fat In Bed

The benefits of exercise as a fat burner continue long after your cool down. In fact you can even burn fat whilst you’re asleep. This increased energy expenditure, that is, calorie burning, is much greater when you have been exercising at at least 75% intensity. That’s running beteen a 7 and 8 out of 10 on the Rating of Perceived Exertion (RPE). So keep those interval training sessions going.

You might be able to think of other ways to increase your energy expenditure in bed. If so, go for it!

 

2. Don’t Work in the “Fat Burning Zone”

The body does burn a greater percentage of calories from fat in the “fat burning zone”  -about 65% of your maximum heart rate, but overall, you burn more calories when you work at a higher intensity. So whilst a lower percentage of calories burned will come from fat when you are working at a higher intensity, you will burn more calories overall at a higher intensity, and  more calories from fat as well. It’s the overall calories burned that is important in weight loss, so keep the intensity up (when your body is ready for it)

The chart below explains it.

Low Intensity – 60-65% MHR High Intensity – 80-85% MHR
Total Calories expended per min. 4.86 6.86
Fat Calories expended per min. 2.43 2.7
Total Calories expended in 30 min. 146 206
Total Fat calories expended in 30 min. 73 82
Percentage of fat calories burned 50% 39.85%

Source: From The 24/5 Complete Personal Training Manual, 24 Hour Fitness, 2000

 

3. Enjoy Your Exercise

There’s  no use choosing an exercise that you are not going to enjoy. Whilst energy burned is dependent on the activity itself, it is also dependent on how much effort you put in, how well you can perform the activity, how long you do it for, and how often. I’m not saying you have to leap out of bed at 5:30am on these cold, wet, dark mornings, and say “Yippee I’m going for a run” but if you choose something you enjoy most of the time, you’re far more likely to keep it up. Train with a group, set yourself a goal such as a fun run to get you through those tough moments where you feel totally unmotivated (which believe it or not we ALL have), choose something practical and accessible. Running is a great exercise for enjoyment. You can do it with friends, you can go as hard or as easy as you like, it’s very accessible – just a pair of shoes, shorts and t-shirt, plus your undies of course, and you’re away. What could be more simple and enjoyable?

 

4. Use Large Muscles to Up the Calorie Burn

You need to get your large muscle groups involved for a serious fat burning workout.  The greater the overall muscle involvement, the more calories will be burned in the workout. Anything that recruits your thighs and bum will be a winner on the fat burning front. Running of course fits the bill, as does rowing, so if you’re at the gym, jump on the rowing machine. Don’t overdo the rower first up though – it is very hard on your lower back so you need to do  little bits frequently and build up to rowing further, rather than go hammer and tongs on your first attempt. 2 -5 mins first up at a slow pace will be fine.  Take a look at this video for some good tips on rowing technique. Well worth the 5 mins before you jump on a rower.

 

5. Develop Your Aerobic Capacity

Fat burning activity has to be sustained for a reasonable length of time, for maximum results. Whilst sprinting might be a great exercise, you can only sprint for a short period of time. For maximum fat burning, you need to be doing at least 20 minutes of fat burning exercise a few times a week. Increase your endurance by doing longer, slower bouts of exercise -perhaps a long slow run, or running efforts of 10 minutes duration at a slightly faster pace than if you were just going out for a jog,  with a  few minutes recovery interval in between efforts. You’ll find you’ll be able to do more repeats of your faster fat burning exercise if you improve your endurance.

 

6. Interval Training Maximises Calorie Burn

Interval training is where you have an effort, and then a rest interval. Contrary to popular belief, the “interval” is actually your rest time-which has little impact on fat burning, but is interesting just the same. Interval training is great: if used correctly it can make you run faster, improve your aerobic fitness, and burn more fat. In short, it makes very effective use of your time. To get the most out of interval session, join a group where you can be overseen by a trainer or coach who can help to ensure you are working at just the right intensity, and doing just the right amount of training.

 

7. Carry That Weight

Weight bearing exercise such as running uses more calories than those in which your weight is supported, such as swimming or cycling. It’s because you have to move your body weight against gravity.

 

8. Run In A Fasting State?

Does running before breakfast burn more fat? Possibly. If the body exercises in a fasting state (for example when you have gone overnight without eating) it has to rely on fat stores for energy. On the other hand, the lack of a ready energy supply could mean you don’t work as hard or for as long as you might have done otherwise. Play around with this and try the same session both before you’ve eaten and then on other days when you haven’t. Compare your times, how you felt, how long you could sustain the effort and make a judgement for yourself on this one.

 

9. Keep Challenging Yourself

If you want to keep up the results, you need to keep up the intensity. As you get fitter, you’ll be able to run faster, and do more. Your body will be able to cope with increasing demands on it. If you just keep doing what you’ve always been doing, the benefits will plateau.

 

10. Keep On The Move

Research has found that leaner people tend to stand and move around more than overweight people in their normal daily life. The Mayo Clinic found that non -exercise activity thermogenesis (NEAT) was up to 350kj (or nearly 90 kilocalories) higher each day, in people who move around more. If you have a desk job, set your alarm to get up and move around every 30 minutes. It’s so easy to get bogged down in something and have a couple of hours go by without you every having moved more than your fingers and your eyelids! Take a look at sitting can be deadly for more on why you should get up and move around.

Walking to the biscuit tin doesn’t count by the way!

 

 

Image courtesy of AKARAKINGDOMS / FreeDigitalPhotos.net

DISCLAIMER: Any information contained in this document is obtained from current and reliable sources and is solely for the purpose of interest and information.  Individuals receiving this information must exercise their independent judgment in determining its appropriateness for their particular needs. The information and training advice is general in nature and may not be suited to the recipient’s individual needs. Medical advice should always be sought when starting an exercise program. As the ordinary or otherwise use(s) of this information is outside the control of the author, no representation or warranty, expressed or implied, is made as to the effect(s) of such use(s), (including damage or injury), or the results obtained. The author expressly disclaims responsibility as to the interpretation of the views contained in this article, ordinary or otherwise. Furthermore, the author shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. The author shall not be responsible for any damages resulting from use of or reliance upon this information. Readers of this document are solely responsible for compliance with all laws and regulations applying to the use of the information, including intellectual property rights of third parties.