By Nancy Clark

In today's food culture, we've demonized certain types of foods, such as those with abundant carbs, fat, salt, sugar. The latest demon is ultra-processed foods. You've seen the headlines: Ultra-processed foods linked to heart disease, diabetes, mental disorders and early death, study finds. Eating processed foods tied to shorter life. You should stop eating ultra-processed foods.

Such fear-mongering headlines influence many athletes to steer clear of ultra-processed foods (UPFs). While that is often the nutritionally wisest choice, the words ultra-processed foods get tossed around way too loosely.

Clickbait headlines can fail to offer a balanced overview. Sports drinks, gels, protein bars, as well frozen meals, store-bought bread, and vanilla yogurt (all UPFs) can be helpful additions to a busy (and budget-minded) athlete's food plan. Will these foods really ruin your health?

This article looks beyond the headlines and offers information to help you better understand what UPFs are and what they are not. Nutrition communicator Liz Ward RD shared this UPF information at the Mass. Academy of Nutrition & Dietetics Annual Meeting (March 2024).

Definition: What is an ultra-processed food?

Foods are categorized by the NOVA (not an acronym) system according to how they have been processed. NOVA has four categories—none of which consider a food's nutritional value:

Group 2. Processed Culinary Ingredients (also called Oils, Fats, Salt, and Sugar)— includes foods from Group 1, but in a different form. Olive oil (vs. olives), white sugar (vs. sugar cane), maple syrup (vs. sap), butter (vs. cream). Again, no mention of nutritional value.

Group 3. Processed Foods—home-cooked & commercially made food with salt, sugar, oil, plus preservatives to extend the shelf-life in foods from Groups 1 and 2. Examples include many foods thought to be good for us: smoked salmon, canned beans, canned tuna, and fresh cheeses.

Group 4. Ultra-Processed Foods— "industrial formulations" with fat, oil, sugar, starch, flavor enhancers, colors, and food additives. This group includes sports and energy drinks, cookies, baked chips, candy, as well as chocolate milk (excellent for recovery after a hard workout); tofu and salted nuts (protein for vegetarians); and packaged whole-grain bread. Many UPFs are nutrient-rich and positive choices for athletes. Hence, you want to think about nutrient density more than NOVA classifications!

What does the science say about ultra-processed foods?

While click-bait headlines proclaim UPFs are linked to heart disease, diabetes, brain health, and early death, the science is less definitive. Most UPF research looks at what people eat—and may overlook other factors that impact health: stress, economic status, exercise, and lifestyle. Research indicates ultra-processed foods such as breakfast cereal and (sweetened) yogurt can—and do—have health benefits.

To date, only one well-controlled study has compared the impact of two-weeks of eating an UPF diet (80%of calories) to a diet with minimally processed foods but nutritionally similar foods (in terms of carbs, protein, fat, and fiber). The results suggest the subjects ate more calories with the UPFs and gained two pounds during the two-week UPF diet and lost two pounds during the two-week minimally processed food trial.

Does this mean the media can rightfully declare UPFs are fattening? No. Research done under highly controlled conditions differs from athletes' "real life" eating patterns (which could easily have fewer calories from UPFs, given the typical US diet gets 60-67% of calories from UPFs ). Plus, two-weeks is a short trial. (This type of research is difficult to do.)

Is processing the problem— or is something else the culprit?

• Emulsifiers (cellulose gum, polysorbate 80) have been linked to negative changes in rats in the gut microbiome. Stay tuned for human studies.
• PFAs are endocrine disrupting chemicals that resist grease, oil & water. They are in food packaging: shiny wrappers on energy bars, grease-resistant microwave popcorn bags, and paper take-out food containers. As of Feb. 2024, PFAs are no longer allowed in food packaging in the US—but has their metabolic damage already been done?
• Is hyper-palatability the problem? Foods made with sugar and fat are more pleasing than sugar-free and fat-free foods—and even sugar and fat itself. Chocolate, for example, offers an appealing mix of sugar and fat that makes it very easy to overeat...

Food for Thought

Before demonizing all UPFs, we really need to look at the whole picture. We know chronic health issues are linked to eating patterns that lack fiber from fruits, vegetables, whole grains, beans, legumes, nuts. We also know that eating excess calories of salt, added sugars, and certain kinds of fat commonly found in UPFs can harm health. But despite popular belief, it is possible to choose a food plan with 90% UPFs and still consume a quality diet.

Ultimately, your overall dietary pattern—what, when, why, how much you eat—and not just UPFs will impact your health. We need to figure out why some people eat too many "addictive" UPFs such as salty snacks, sweets.  We'd also like NOVA to add a category for nutrient-dense processed foods to help resolve the demonization of all UPFs. Sausages and hot dogs should not be in the same category as tofu and peanut butter!

When making your nutrition game plan, there's little doubt that munching on Group 1 nuts and fruits (instead of pre-wrapped bars), and spending more time cooking homemade foods with fresh, locally grown Group 1 foods will be the ultimate winning diet. But convenience is a key reason people reach for UPFs. Try keeping your pantry stocked with minimally processed foods, so you can just as conveniently assemble a quick meal:

— whole grain bread + all-natural peanut butter + banana + yogurt

— rye crackers + canned tuna + cherry tomatoes + cheese.

As always, you want to eat more of best and less of the rest, keeping balance and moderation in mind.

Nancy Clark MS RD CSSD  counsels both fitness exercisers and competitive athletes in the Boston-area (617-795-1875). Her best-selling Sports Nutrition Guidebook is a popular resource, as is her online workshop. Visit NancyClarkRD.com for more information.

Resources:

For a handout on the NOVA Food Classification System with examples of foods in each group: https://ecuphysicians.ecu.edu/wp-content/pv-uploads/sites/78/2021/07/NOVA-Classification-Reference-Sheet.pdf

For more information on hyper-palatable foods: https://www.thinkingnutrition.com.au/food-addiction/?utm_source=substack&utm_medium=email

By Gabe Mirkin

Heat stroke during exercise is a rapid uncontrolled rise in body temperature that can cause you to pass out and can even kill you. It is a medical emergency that can cause permanent organ damage, kidney failure and seizures. It should never happen to you because your body sends you plenty of warning signals as your temperature rises. In 1965, I almost died from heat stroke in an unimportant local race in Arlington, Virginia. I passed out during the race, and I am still embarrassed by the stupidity that I showed when I ignored all the warning signs as my temperature continued to climb.

First your muscles are affected, then your lungs and then your brain.

• Muscles: As your temperature starts to rise, your muscles feel like a hot poker is pressing against them. It is normal for intense exercise to make your muscles burn, but hard exercise does not cause painful burning that feels like fire. Furthermore, the burning of hard exercise is relieved by slowing down, while the muscle burning of impending heat stroke does not go away when you slow down. 

• Lungs: As your temperature rises further, the air that you breathe feels like it is coming from a furnace and no matter how rapidly and deeply you try to breathe, you can't take in enough air. When you exercise intensely, you can become very short of breath, but the air you breathe will not burn your lungs. Burning in your lungs, not relieved by slowing down, signals impending heat stroke. When you feel that the air is so hot that it burns your lungs, stop exercising. This sign means that your heart cannot pump enough blood from your exercising muscles to your skin so heat is accumulating and your temperature is rising rapidly. Your temperature is now over 104 degrees F, and continuing to exercise will raise your body temperature even further so it will start to cook your brain. 
• Brain: When heat stroke begins to affect your brain, your head will start to hurt, you may hear a ringing in your ears, feel dizzy and have difficulty seeing. Then you will end up unconscious. Your temperature is now over 106 and your brain is being cooked just like the colorless portion of an egg that turns white when it hits a hot pan.

Mechanism
During exercise, more than 70 percent of the energy used to drive your muscles is lost as heat, so your heart has to pump the heat in your bloodstream from your hot muscles to your skin where you sweat and the sweat evaporates to cool your skin to dissipate the heat. The harder you exercise, the more heat your muscles produce. Everyone who exercises, particularly in hot weather, has to sweat to keep their body temperature from rising too high.

Risk for heat stroke is increased by:

• any pre-existing illness
• heart disease
• use of various stimulants and recreational drugs such as cocaine, and some prescription drugs
• lack of fitness
• not drinking enough fluid
• exercising for extended periods without eating
• wearing excess clothing that traps heat in your body
• not listening to your body when you feel the warning signs described above

Many cases of heat stroke during exercise occur when a person suddenly increases the intensity of exercise, such as a sprint at the end of a long distance running or cycling race, or an intense run down the field in soccer.

Treatment
When a person passes out from heat stroke, get medical help immediately. Any delay in cooling can kill the person, and you may need an expert to help decide if the person has passed out from heat stroke or a heart attack. Carry the victim rapidly into the shade and place them on their back with the head down and feet up so blood can circulate to their brain. Once it has been established that the person is not having a heart attack, they can be cooled by pouring on any liquid. As you cool them, they may suddenly wake up and talk to you and act like nothing has happened. Don't stop cooling them, because while they are sitting or lying there, their temperature can rise and they can go into convulsions or pass out again. They must be watched for several hours after they are revived.

My Recommendations
When you exercise in hot weather, stop exercising if you start to feel any of the symptoms of heat stroke described here, and find a shady spot to recover. Stay well hydrated, but realize that too much fluid can result in low blood sodium (Hyponatremia), which can also be harmful.

Dr. Mirkin's reports and opinions are for information only, and are not intended to diagnose or prescribe. For your specific diagnosis and treatment, consult your doctor or health care provider.

For more information visit DrMirkin.com
We DO NOT sell, rent or give your e-mail address to anyone.
Copyright 2024, The Sportsmedicine Institute, Inc.

Dr. Gabe Mirkin May 19, 2024

About 60 percent of North American adults suffer from occasional night-time leg cramps, a sudden painful contraction usually of the calf muscles that can last from a few seconds up to 10 minutes or more. Doctors do not know what causes most cases of leg cramps, but usually they are not caused by dehydration or lack of minerals. The leading theory is that most leg cramps come from the lack of a normal nerve reflex that causes a muscle fiber to relax when it is held in contraction. That is why people who suffer recurrent leg cramps should be checked for conditions that can cause nerve damage, such as vitamin B12 deficiency or diabetes. Cramps occur most often at night when you are sleeping, when you exercise vigorously, when you tear a muscle, or when you keep your leg in an awkward position, such as sitting in a chair in the same position for a long time. If you have frequent night-time leg cramps, check with your doctor for a medical workup to look for a cause.

What is a Muscle Cramp?

When you turn during sleep, you contract your calf muscles, which stretches their tendons. This stimulates nerve stretch receptors in the tendon and sends a message back to the spinal cord, telling the calf muscles to contract. After you contract a muscle, reflex messages are sent along nerves to the spinal cord to relax that muscle. If the message to relax is blocked, the muscle stays contracted and you develop a cramp. Cramping during sleep is usually due to an exaggeration of the normal muscle reflex that causes the muscle to stay contracted and hurt.

Older people and those who do not exercise are at increased risk for cramps because they have smaller and weaker muscles. Cramps are more likely to occur in hot weather because muscles fatigue earlier with higher temperatures. Cramps are more likely to occur during intense exercise that requires you to use your fast twitch strength fibers that fatigue earlier than your slow twitch endurance fibers.

What To Do When You Develop a Leg Cramp 

When you get a leg cramp, you should gently try to walk it out while you massage the contracted muscle with your hands. Don't put great force on the contracted muscle because you may tear it. If the cramp continues, apply cold compresses, which can relax the contracted muscle and numb the pain. Keep on gently massaging the muscle.

Preventing Leg Cramps

You can often prevent night-time leg cramps if you:

• exhaust the stretch reflex before you go to bed by stretching your calf muscles 
• apply a heating pad for 10 minutes before you go to sleep 
• start a regular exercise program to strengthen your calf muscles. If you are a non-exerciser, the best exercises may be a stationary bicycle or a spinning class.

Quinine may be used to treat night-time leg cramps (Brit Med J, Jan 7, 1995; 310(6971):13-17), but the U.S. Food and Drug Administration stopped over-the-counter marketing of this remedy because of concerns about irregular heartbeats. Doctors can still prescribe quinine pills for relief of leg cramps, but they can cause birth defects and miscarriages, so they should not be taken by a pregnant woman. Quinine can also cause ringing in the ears, headache, nausea, disturbed vision, chest pain, asthma and other problems.

Work-Up for Frequent Leg Cramps

Most causes of leg cramps are harmless, but if you suffer frequent leg cramps, you need a detailed medical workup; check with your doctor.

Treatable causes of frequent leg cramps include:

• all conditions that can cause blood vessel damage such as arteriosclerosis
• partially obstructed blood vessels
• pinched nerves in the back
• muscle damage
• nerve damage
• kidney disease
• abnormal mineral levels such as lack of potassium or calcium
• vitamin B12 deficiency
• abnormal hormone levels such as low thyroid
• diabetes
• dehydration
• medications such as birth control pills, diuretics (which are often prescribed for people with high blood pressure), steroids, asthma medications such as albuterol, pain meds such as naproxen or pregabalin, statins to lower cholesterol, and so forth (BMJ Clin Evid, 2015, 1113; Am Fam Physician, 2012, Aug 15;86(4):350-3). 
• about 30 percent of night-time leg cramps may be due to venous insufficiency or varicose veins. Vein specialists can do an ultrasound evaluation of valves to see if they gap, allowing stretching of the vein to create contracture (a cramp). This can be easily treated using laser or chemicals to close the inefficient valves or veins.

My Recommendations

When you get a leg cramp at night, get up and start walking cautiously while gently massaging the cramped muscle. The cramp should ease up within a few seconds. Stop walking immediately if the pain worsens because you can tear the muscle. For the next few nights, before you go to bed, try stretching your calf muscles to exhaust the stretch reflex with "wall push-ups." Stand about an arm's length from a wall or countertop with both feet flat on the ground. Place your hands on the wall and slowly bend your elbows to bring your upper body closer to the wall. Hold for the count of ten and then push your self away from the wall by straightening your elbows. Repeat several times. Stop immediately if you feel sudden pain.

Dr. Mirkin's reports and opinions are for information only, and are not intended to diagnose or prescribe. For your specific diagnosis and treatment, consult your doctor or health care provider.

For more information visit DrMirkin.com
We DO NOT sell, rent or give your e-mail address to anyone.
Copyright 2024, The Sportsmedicine Institute, Inc.

By Eli Post and Alex Post

There is a thin line between courage and stupidity. These riders display life or death courage in their actions. However, you would be foolish to attempt to mimic them. We advise to sit back and enjoy these short videos clips. 

Fresh Mountain Air

https://www.instagram.com/reel/C4GuqKOKiwa/?igsh=MWJ3ZGsxdnJ4aXZmMQ==

Lakeside Cliff Descent 

https://www.instagram.com/reel/C3n4E8xSLeI/?igsh=dGhpOXpuc2o1ZzR2

By Barbara Jacobs

3rd Annual Bike Ride and Swap - Rescheduled to Saturday, May 11th

Log early season miles, see part of Paul Revere's ride, get rid of old bike stuff, and find gems on the FREE STUFF tables - all in a single day!  

Rides depart at 10am (38 miles) and 11am (25 miles) and the Swap Meet runs from 1 to 4pm.  For full details and to register go here.

Paceline Clinic - Saturday, May 18th

Are you interested in learning to ride in a Paceline. This CRW member only event is limited to 20 people. Those who have always wanted to ride a paceline will be shown how to do this safely and effectively within small groups of about 5 each.  Speed is NOT the objective for this instruction session, rather we want to get people feeling comfortable riding more closely together, get everyone to ride safely and predictably, and how to exchange the lead rider for each paceline. Go here to learn more and register 

CRW Spring Century, Sunday, May 19th - Register Now

North to New Hampshire is a long-time CRW favorite century event, beginning at the Wakefield High School, heading to NH and back, and winding though some of NH's more scenic roads.  New 2024 CRW special edition participants sprockets will be available for riders who did not earn one in 2023. 

The CRW Century Series is open CRW members only. To attend you must be a current CRW member. Click here to join.

The first of our Century rides is now on the calendar and open for registration! 

Register NOW!

This will be the first chance for many to put some serious miles down for the season.

Not ready for 100 miles?

Metric and half-century options are available. 

By Jerry Skurla

Saturday, May 11th - 3rd Annual Spring Swap Meet & Rides in Lexington, MA 

Log early season miles, see part of Paul Revere's ride, get rid of old bike stuff, and find gems on the FREE STUFF tables - all in a single day!

Location is Harrington Elementary School, 328 Lowell Street in Lexington, MA.

Rides depart at 10am (38 miles) and 11am (25 miles) and the Swap Meet runs from 1 to 4pm.  Check out the event on the Ride Calendar for full details and to register.

Just use the checklist list below to identify stuff you no longer need or want:

a - Complete bikes, frames, wheels, and tires 

b - Components, parts, accessories, and tools

c - Car racks, travel cases, bike racks, and bike bags

d - Clothing including shoes, jerseys, hats, and jackets

Like last year, there will be "free stuff" tables to give away items, and find free gems for yourself. You can also sell your stuff and buy from others. Everyone wins!

By John O'Dowd

On Saturday April 27 The Bike Connector in Lowell hosted a bike repair and maintenance workshop for CRW members. 

Mechanics Macon Lockery and Tad Irving instructed participants on proper care of chains, derailleur adjustment, and brake adjustment. Particularly helpful were tips on how to make quick adjustments while on a ride. Also, they gave participants an understanding of how these components work and explained the differences between side pull caliper brakes and mechanical and hydraulic rotor brakes.

CRW members brought their own wheels and learned how to repair a flat tire. Patty Grasso (CRW Ride Leader and a Bike Connector Board Member) went into detail about the right and wrong way change a flat tire. Everyone knew how to fix a flat by the time they left.

The Bike Connector is a Lowell charity serving the greater Lowell area. Their mission is to help people who can't afford bikes to get one. One of their programs offers school children the opportunity to get a bike if they do the work needed to repair it under the direction of the Connector's mechanics. They accept old bikes as donations and sell repaired bikes to the public, too. The Bike Connector is always looking for volunteers, if you are interested in volunteering complete the form here.

By Ron Gluck

Over the last several years our team of attorneys has represented the families of many cyclists killed or critically injured by right turning trucks. Sadly, the incidents leading to the tragic outcomes were preventable. In one of the most publicized cases, which involved the death of 33-year-old physician Anita Kurmann, the right turning truck struck and killed Dr. Kurmann as she was pedaling along the right most side of Massachusetts Avenue at the intersection of Beacon Street near the end of the Mass Ave bridge in Boston. The driver of the truck was not charged in the incident. The point of this article is not to quarrel with decisions made by police departments or District Attorney offices concerning their decisions to charge or not charge the drivers with vehicular homicide. That subject is for another day and time. The point of this article is to remind cyclists of the reality of the dangers of being close to the right side of trucks when those behemoths make their right turns.

In a case on behalf of a family whose loved one was severely injured by a trash collection truck in metro Boston, the truck passed the cyclist who was slowly pedaling to work and then made a right turn even though the cyclist was in the zone of danger. The truck was outfitted with much of the required safety equipment which, if used properly by the driver, would have prevented the catastrophic result from occurring. Tragically the driver failed to make proper use of the mirrors, ran over the cyclist, and then came to a stop with the cyclist stuck under the truck’s front tire. A clear case of horrific truck driver error causing severe and lifelong injuries for the cyclist.

The law in Massachusetts makes it illegal for operators of motorized vehicles including trucks to make a right turn which cuts off the pathway of bicyclists. Perhaps this creates a false sense of safety for cyclists who may feel there is a zone of safety which will not be violated by the right-turning truck driver. Perhaps the cyclist looks at the truck and sees a variety of mirrors which should, when used properly, eliminate the “blind spot” which can put the cyclist at risk. In reality, these safety measures and legal protections should provide NO sense of safety for the cyclist who is approaching the right turn because in order for these measures to protect the cyclist, the truck driver must abide by the law and make proper use of the mirrors. The truck drivers must also be fully alert and vigilant to the presence of cyclists on the roadways as they approach the road onto which they will be making the right turn and there is absolutely no guarantee that the driver will do so. These safety devices and legal protections are only as effective as the driver of the truck makes them. We know that truck drivers are sometimes careless and the consequences for the cyclist and his or her family can be catastrophic. To be safe, cyclists should make every effort to back off and slow down to let the truck pass them where a right turn is approaching. Do not let the fact that you, as the cyclist, have the right of way fool you into thinking that the truck will stop or slow for you. On the contrary, assume instead that the driver will not be careful! Assume that the driver will not notice you as the truck passes you on its way to the right turn ahead. Assume that the truck driver will not make proper use of the mirrors.

​As the cycling season ramps up into high gear, please remember to exercise extreme caution in these” right turn” situations. Let the truck, or even a car, make the turn before you arrive at the point of the right turn.

My best to all of you for an enjoyable and safe riding season.

Ron Gluck

If you have questions about a particular incident or more generally about the subject matter of this column, feel free to contact Ron Gluck at gluck@bwglaw.com. 

Ron Gluck is a founder and principal at Breakstone White and Gluck in Boston. Throughout his 35 year legal career Ron has represented seriously injured individuals in a variety of cases including cycling accidents involving catastrophic injury and wrongful death. Ron is a CRW member.

By Dr. Gabe Mirkin

When you exercise in hot weather, you don’t need special sports drinks or power bars. A review of 46 studies shows that a person can prolong endurance by eating before and during exercise (Scand J Med Sci Sports, 2018 May;28(5):1476-1493). However, even the most elite athletes can get the nutrients they need from ordinary foods, water and salt. Healthy and fit people usually don’t need to drink or eat when they exercise at a casual pace for less than two hours. They can prolong their endurance by taking:

Mild Dehydration Does Not Impair Exercise Performance

Most competitive athletes can maintain their speed and efficiency by drinking when they feel thirsty (J Hum Kinet, 2021 Jul; 79: 111–122). Racers do not slow down until they have lost enough fluid to lose at least two percent of their body weight. For a 150-pound person, that’s at least three pints or three pounds of water. Losses greater than five percent of body weight can decrease work capacity by about 30 percent (Am J Clin Nutr, August 2000;72(2):564s-572s).

The Gatorade Sports Science Institute in Barrington, Illinois published a study showing that 46 percent of recreational exercisers are dehydrated (Applied Physiology, Nutrition and Metabolism, June 2006). However, the study did not say that they were harmed, with good reason. There is no data anywhere to show that mild dehydration affects health or athletic performance. People must lose a tremendous amount of fluid before it affects their performance (Medicine & Science in Sports & Exercise, October 2006). On average, a world-class marathon runner drinks less than a cup an hour during a race (a cup of water has 250 milliliters). This is far less than the amount formerly recommended by the American College of Sports Medicine. That amount could dilute blood salt levels to cause brain swelling. that could kill you. On the basis of our present knowledge, it may not be safe for mediocre athletes to take in more than 800 cc per hour (3.5 cups). Recent studies show that fit humans can tolerate significant fluid loss before their performance suffers, and that most cases of muscle cramps are not caused by dehydration or salt loss. They are caused by muscle or nerve damage and can be controlled by stopping exercise and stretching the cramped muscle.

Lack of Sugar

Low levels of sugar can cause muscle pain and weakness called “hitting the wall” that occurs in long distance runners, and confusion and passing out (called “bonking”) that occurs in cyclists. Your muscles use primarily sugar and fat for energy. You have an almost infinite amount of fat stored in your body, but you start to run out of sugar stored in your liver after 70 minutes of intense exercise. Bonking (in cyclists): There is only enough sugar in your bloodstream to last three minutes at rest. To maintain blood sugar levels, your liver constantly releases sugar into your bloodstream. However, there is only enough sugar stored in your liver and muscles to last about twelve hours at rest and less than 70 minutes when you exercise intensely. Your brain has almost no stored energy, so it gets almost all of its energy from the sugar carried to it in your bloodstream. When liver sugar levels drop, your blood sugar levels must also drop and your brain has lost its main source of energy. Your brain then cannot function normally and you feel weak, tired, and confused, and can even pass out. Hitting the Wall (in runners): Muscles have only a limited amount of sugar stored in their cells. When muscles run out of their stored sugar supply, they hurt as you exercise and become difficult to coordinate. A limiting factor to how fast you can move is the time it takes to bring oxygen into your muscles. Since sugar requires less oxygen than fat does to power your muscles, you will slow down when your muscle sugar and blood sugar levels start to drop.

Sugar before Competition or Intense Exercise

Take sugar no more than five minutes before you start your competition. Do not take sugar earlier than that because when you eat sugar and your muscles are not contracting, you can get a high rise in blood sugar that causes the pancreas to release large amounts of insulin. This can cause a drop in blood sugar levels that can tire you. On the other hand, exercising muscles draw sugar rapidly from the bloodstream without needing insulin, so taking sugar during exercise or just before you start usually does not cause the high rise in blood sugar levels.

During your competition or exercise session, take sugar before you feel hungry. Hunger during exercise is a very late sign of not getting enough calories. By the time you feel hungry, your body will be so depleted of sugar that you will have to stop or slow down so you can eat a lot of carbohydrate-rich food just to restore your sugar supplies. On days that are not too hot, your exercise performance will be harmed far earlier by lack of sugar than from lack of water. The rule of thumb is that athletes should take a source of sugar during all competitions lasting longer than an hour.

Lack of Salt

The only mineral that you need to take during prolonged exercise is sodium, found in regular table salt. Potassium, calcium and magnesium deficiencies almost never occur in healthy athletes (Medicine & Science in Sport & Exercise, October 1999). Just about everyone agrees that you need to take in extra salt during extended athletic competitions in hot weather. Salt is necessary to hold water in your body, prevent muscle cramps, and help keep your muscles contracting with great force. However, excess intake of salt may raise blood pressure and increase risk for heart attacks, particularly in people who have big bellies and high blood sugar levels. Most processed foods are full of extra salt, so people who eat the typical North American diet will almost always get all the salt they need from their food and should restrict adding extra salt from a salt shaker.

If you do not meet your needs for salt during extended exercise in hot weather, you will tire earlier and increase your risk for heat stroke, dehydration and cramps. During vigorous exercise lasting longer than three hours, you should eat salty foods such as salted nuts, peanuts or potato chips. Some sports drinks contain salt, but since salted drinks taste awful, the amount added is so small that it may not be enough to meet your needs. One study showed that you cannot replace all of the salt lost through exercise by drinking the sports drinks that contain salt, since they typically contain very little salt (British Journal of Sports Medicine, April 2006).

You Can Take In TOO MUCH Fluid

The American College of Sports Medicine formerly recommended fluid intake of 1200 cc (five cups or two average-size water bottles) per hour, but for people who are not exercising near their maximum, this can be too much (Clinical Journal of Sport Medicine, July-August 2005). People exercising near their capacity, and not slowed down by fatigue, probably do not have to worry about limiting fluid intake. They are working so hard at maintaining intensity that they do not have enough time to drink too much. On the other hand, people slowed down by fatigue or those who are out of shape should limit fluid intake, probably to no more than two water bottles per hour.

Some people develop hyponatremia (low salt) when they drink too much. It almost always occurs in people who attempt events that are beyond their training levels. They run out of energy, slow down and focus on drinking fluids instead of maintaining their pace. Hyponatremia is caused by drinking too much fluid, not by excessive loss of salt in sweat or by the stress of exercising. The extra fluid expands blood volume and dilutes blood salt levels. This causes blood salt levels to drop to low levels, while brain salt levels remain normal. Fluid moves from an area of low salt concentration into areas with high salt levels, so in hyponatremia, fluid moves from the bloodstream into the brain to cause brain swelling. Since the brain is enclosed in the skull, which is a tight box, the expanding brain has nowhere to go and the squashing can cause a headache, nausea and blurred vision. Since these are the same symptoms caused by pure dehydration with normal blood salt levels, the only way to diagnose the condition is with blood tests. As blood salt levels drop even lower, the person becomes confused, develops seizures and falls unconscious. You should suspect hyponatremia if the person has been exercising for a long time and has been drinking often. Under any circumstances, a person who is confused, has seizures or has passed out should be sent to a hospital immediately. Hyponatremia requires skilled management because the first impulse is to give intravenous fluids, which would dilute blood salt levels further to cause more brain swelling that could kill the patient.

My Recommendations