Tag Archives: water

Nutrition and Hydration Considerations in Cold Weather

Posted on by oakwoodsportsmedicine

For some of you, winter exercise is just another daily adventure, especially if you live in a northern climate. For others, the thought of beginning an exercise routine in the midst of snow, sleet and road salt, it can be overwhelming. Today’s entry is going to be a gentle reminder for all of you. Dehydration and lack of proper nutrition during cold weather can be dangerous.

Hydration Considerations

Water is an essential component for all of the processes the body completes each day. Approximately 70% of the body is water, mostly stored in the tissues at the cellurlar level. Water is essential for the micro processes that take place in our bodies every day. Without proper hydration, these processes don’t work nearly as well and in extreme cases, stop working all together. Our kidneys regulate the amount of water loss through urine output while thirst and hunger can help regulate daily water volume. Athletic performance decreases with the loss of 2% of bodyweight and more than 2 litres can be lost through exercise!

During exercise the heart rate increases, plasma osmolality increases (osmolality is a measure of the concentration of things like sodium, potassium, glucose and other ions in the blood) , there is a decreased blood flow to the skin (for cooling) and a resultant increase in core body temperature ( a core temp too high can be dangerous!).

Dehydration is indicated by urinary markers such as a reduced urine volume, a high urine specific gravity (USG), a high urine osmolality (UOsm), and a dark urine color (UCol) . To a person, dehydration may look or feel like irritability, headache, fatigue, Weakness, dizziness and nausea. Dehydration negatively affects training, competition and recovery.

This graph represents the decrease in performance as dehydration increases.

The goal is to replace 100% of sweat lost during exercise; that’s about 1/2L of fluid per kg of weight loss. The American College of Sports Medicine (ACSM) recommends 125 ml (5 ounces ) every 20 minutes. Be aware that technology (clothing) may inhibit an appreciation of sweat rate or water loss and cold weather diminishes the thirst mechanism. Staying safe and healthy during cold weather depends on your awaress, recognition and education.

Nutritional Considerations

Energy expenditure in adverse weather (snow/ice) is two times greater than on a regular surface (same speed—walking). The heavier clothing worn to protect a person from the elements  increases energy expenditure.  Vasoconstriction reduces blood flow to peripheries (arms and legs) and thereby decreases fat utilization. Glycogen utilization increases in cold weather which results in fatigue.

A person’s rate of exercise in the beginning of a session can maintain body temp. With a prolonged session, the stored reserves (glycogen) will be depleted resulting in fatigue. With fatigue will come a decrease in exercise rate followed by less muscular activity. The resultant lower body temperature is a precursor to hypothermia, a potentially fatal outcome if not handled properly.

All of this means the body’s need for energy/food increases during cold weather exercise.  Obviously the challenge is to keep energy sources from freezing, ensure ease of access/consume and be palatable. A food source with high carb content is recommended. Eat before leaving on an outdoor run (~2 hours prior) to replenish liver glycogen. During the session consume 30-60 grams of carbs every hours to maintain blood glucose levels.

A year-round outdoor exercise program is very achievable if a person learns about the importance of how hydration and nutrition affect the body in cold weather.

Hydration Choices During Warm Weather

Posted on by oakwoodsportsmedicine

Equipment in good working order – check.

Food source appropriate for the day’s adventure – check.

Sunscreen – check.

Fluid replenishment – check and double check.

It’s summer time with temperatures and humidity reaching near-record levels. As an outdoor enthusiast or athlete, fluid replenishment should be right at the top of your list.

Sweating is a natural byproduct of exertion and provides a mechanism for dissipating our body heat. Sweat rolls over the skin and provides for cooling of the skin and superficial tissues. The more we sweat, the more fluids we lose and become dehydrated. We also lose valuable electrolytes such as sodium and potassium when we sweat.

Dehydration of a mere 2% of your body weight causes a decrease in performance – for high performance athletes this is can be the difference between a place on the podium and watching from the stands or training room. Dehydration in those of us with average abilities, still decreases our performance and places us at greater risk for heat related problems and conditions.

Engaging in intensive athletic events, practice or training in high heat and humidity is a potential situation for a number of heat related conditions.

Heat exhaustion – is a result of exposure to high temps coupled with a high level of exertion over several hours or days, resulting in a state of dehydration and often accompanied by dark, pungent urine, muscle cramps, headache, dizziness, fatigue, nausea, profuse sweating and elevated heart rate (see performance decrease with dehydration above). Remove yourself from the environment preferably in air-conditioning, take a cool shower or sponge bath, replenish fluids, rest.

Heat stroke – is a medical emergency! Heat stroke often is a progression from the milder heat related conditions (exhaustion, cramps) that are left untreated or unrecognized. Prolonged, intense exercise in hot environments >>>dehydration>>>the body’s cooling system fails. Throbbing headache, red-hot-dry skin, lack of sweating, core body temperature over 104 degrees, confusion, disorientation, elevated heart rate all or in part may be present.

Call 911 and until the ambulance arrives, get out of the hot environment, rapidly cool the person by applying ice packs to the armpits, groin, neck; immerse in cool water tub or shower.

Hyponatremia – is a condition that can be caused by, among other things, excessive loss of electrolytes over a relatively short time period. A physical examination, blood test and urinalysis will assist a physician in making the clinical diagnosis of hyponatremia.

An Ounce of Prevention Is Worth a Pound of Cure

Sports drinks are beneficial. However, the marketing cog of companies wants you to believe (and purchase) their products are necessary all day, every day. That’s not quite the case – there’s a time and place for everything.

For example, if an apparently healthy adult walks the dog in the evening for 3 miles, in hot, humid weather, then water is probably the drink of choice to consume before, during and after the walk.

For the landscaper performing strenuous physical activity for hours at a time in the hot, humid weather, a sports drink in addition to water is more appropriate.

A triathlete completing a training run during lunchtime and then a bike ride in the evening, should consider water and a sports drink following the run, before, during and possibly after the bike ride. Also a small meal or two to refill the energy stores between training sessions.

Youth athletes should be encouraged to drink plenty of water during their practice session and sports drink following the activity.

Heat illness can be prevented with education, proper planning, having resources on hand and a watchful eye.

Above All Else…It’s About Player Safety – Part Deaux

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An update:

City of Taylor officials released the results of tests conducted at the facility that hosted the MAHA tournament games this past weekend. Several dozen players and family members of players became ill on the last day of the tournament.

News reports pointed at the possibility that the water in the facility, the Taylor SportsPlex, was contaminated. It was not.

Ice cleaning equipment, Zamboni, were the early target of criticism as was the air quality in the facility. The Zambonis at the SportsPlex are electric, not propane or gas fueled. Propane or gas fueled Zams, when not properly maintained or are near the end of their useful life, can produce fumes (carbon monoxide) that affect the air quality in which they operate. The air quality at the SportsPlex was checked late Sunday night and found to be clean.

Food poisoning was eliminated early on during investigators inqueries. The concession stand at the SportsPlex has recently been inspected and found to be in tip-top condition. Not all of the players ate food from the concession stand. Most ate at their homes or other restaurants. Next.

Student-athletes that participate in close contact sports are often more susceptible to contracting and sharing colds, viruses and skin conditions. Hockey players sit next to each other in a small room and small bench, allowing for shared airspace. Wrestlers are always involved in close contact with their opponent or team mate. Water bottles on the bench are typically shared among several players. Oakwood Sports Medicine emphasizes with teams the importance of staying healthy during the season – that is proper hand washing, not coming to school/practice when ill, using only their own water bottle or single use cups, not sharing towels in the dressing room or shower.

Yesterday we blogged about this event and norovirus and while the exact cause will likely be a “best guess”, we thought it important to reiterate the importance of prevention when dealing with sick or ill athletes.

Facts About Norovirus:

You can decrease your chances of becoming infected with norovirus by:

  • Frequent hand washing with warm water and soap (alcohol based hand sanitizers do NOT work against norovirus)
  • Promptly disinfecting contaminated surfaces with household chlorine bleach-based cleaners
  • Washing soiled clothing and linens
  • Avoiding food or water from sources that may be contaminated
  • Cooking oysters completely to kill the virus
  • Don’t share water bottles or towels with team mates

Guide for participating in athletics when ill:

  • If you have a fever, vomiting or diarrhea – STAY HOME!
  • Drink clear fluids to replace the large quantities of fluids lost with vomiting, a fever or diarrhea.
  • Consult your doctor if a fever lasts more than 2-3 days.
  • Generally, participation in practice or games with a head cold, congestion or allergies is acceptable unless the symptoms of those conditions are so severe that the athlete is unable to fully participate safely.
  • Recovery from a virus may take longer than expected. Use the additional time away to restore your energy, replenish your food or fuel stores with a proper diet and most importantly, avoid the chance of recurrence by returning to sport too early.