Keep yourself safe while exercising in the heat

With memorial day just around the corner, warmer temps are soon to follow. As the summer begins, heat-related issues during exercise become more common. Before I discuss the tips to help you safely exercise in the heat, it's important to understand how heat and humidity affect your body during exercise.

As you exercise, your muscles create heat. To keep your body safe as you begin to build up internal heat, your body increases your sweat rate to remove heat from the inside of your body – this happens through evaporative cooling. Overtime, as you become dehydrated (from fluid loss), blood volume decreases. As a result, blood gets thicker. And the more blood going to the skin means less blood going to your heart which means less blood to your working muscles. To maintain cardiac output (the amount of blood pumped by the heart per minute), heart rate increases in order to supply the working muscles with blood. But due to a decline in blood availability (because of cooling), less blood is available to go to the working muscles. When the body can no longer take care of all of its responsibilities (remember - all of this is happening so you don't die in the heat), your body will start to slow down by shutting down to keep you safe. If you ignore the signs of overheating, heat builds up in your body, your core temp increases and you are at risk for overheating and may experience heat stroke.

Here are a few helpful tips for exercising in the heat:

Acclimatization
Complete heat acclimatization requires up to 14 days but body systems of the body adapt at varying rates. Be mindful that every time you exercise in the heat, you gain more tolerance but it could take at least 2 weeks for you to feel more comfortable exercising in the heat. But there's no point suffering in the heat if you are unable to complete a quality workout, which means sometimes you just need to exercise indoors.

Change in physiology
It is very important to lower the intensity during the first 2 weeks of exercising in the heat (ex. early summer) as your body is trying to improve control of cardio functioning. Be mindful that acclimatization will require you to reduce your effort/intensity so be OK with seeing slower paces in the first few weeks of acclimating. You will likely notice an increase in cardio strain and your perceived exertion will increase. You may also feel more tired, fatigued and exhausted than normal. Positive cardio adaptations occur in the first 5-10 days whereas changes in sweating mechanisms can take 10-14+ days.

Training modifications
Consider splitting up your workout (half outside, half indoors). Find shady areas to exercise. Opt to exercise indoors when the humidity is very high. Or, try to workout when it's not as hot (early morning or early evening). If you try to push your normal efforts in the heat, your body cannot safely adjust to the heat. 

Hydration
The symptoms of underfueling and dehydration are not pleasant.
A sport drink provides a practical and easy way to obtain fluids, electrolytes and carbohydrates - in the precise formulation - to optimize digestion and absorption. If you are exercising in the heat for more than an hour or you are sweating perfusely in the heat, opt for a well formulated sport drink (at least 30g carbohydrates, 240mg of sodium and at least 16 ounce water per hour).
Although your daily diet helps to keep you nourished and fueled, the diverse nature of hot and humid weather validates the importance of consuming well-formulated sport nutrition drinks during specific outdoor workouts.

Females
Females who menstruate regularly each month may notice an increase in thermal strain during exercise during the luteal phase (high hormone phase) before and during menstruation. The increase in progesterone causes body temperature to increase in preparation for the fertilization of an egg. When fertilization does not occur, estrogen and progesterone decrease before the follicular phase. The high concentration of progesterone during the luteal phase affects fluid balance, causing females to feel bloated from fluid retention. Additionally, whereas females are more likely to feel cold during the estrogen-dominant follicular phase, progesterone acts on the hypothalamus (temp control center) which increases body temperature. Females may feel warmer than normal, which makes it more difficult to dissipate heat (although a helpful physiological response for racing in cooler weather events). Females should be mindful of how the body responds to training in the heat, specifically in the 7-10 days before menstruation and adjust efforts accordingly.

Minimize heat stress
There are several ways to minimize heat stress. Your exercise gear should be breathable, light, wicking and should help you stay cool and minimize exposure to the sun. Your clothing should protect the areas of your body that are most exposed to the sun (ex. back, neck, shoulder, face). Always wear broad spectrum sunscreen when you train outdoors and reapply. Wear a cooling towel around your neck and regularly re-wet throughout your run. Bring a sport drink with you and sip consistently (every 10-15 minutes). Search for shaddy sections to run and select "cooler" times in the day to workout.

Know the warning signs
Identify the warning signs of heat cramps (muscle cramps), heat exhaustion (thirst, profuse sweating, fatigue, pale and cool skin, weakness, headache, nausea, chills/goose bumps, cessation of sweating, faintness, dizziness) and heat stroke (strong and rapid pulse, hot and dry skin, confusion). If you suddenly feel like you are experiencing a heat related illness, stop exercising, get into a cool environment and drink electrolyte-based liquids. An extreme loss of appetite, excessive sleepiness, headache, chills or abnormal fatigue during or post workout can all be signs that you are not properly hydrating (or fueling) during your workout.

Nutrition tips to help you excel in a warm weather race

As you go from winter to spring to summer, it takes much more effort and energy to maintain a "normal" pace as the temperature rises. As a way to keep your exercising body safe in the heat, your body increases your sweat rate to remove heat from your body through evaporative cooling. As you become dehydrated (from fluid loss), blood volume decreases. In turn, more blood going to the skin means less going to your heart. To maintain cardiac output (the amount of blood pumped by the heart minute), heart rate increases in order to supply the working muscles with blood. But due to a decline in blood availability (for cooling), less blood is available to go to the working muscles. When the body can no longer take care of all of its responsibilities (remember - all of this is happening so you don't die in the heat), your body begins to shut down to keep you safe. If you ignore the signs of overheating, heat builds up in your body, your core temp increases and you are at risk for overheating and may experience heat stroke.
If you've ever struggled running in the heat, you are not alone. There are a few primary reasons why performance declines in warmer temps.

1) An increase in overall body temperature. Similar to a fever, the higher your core temperature, the greater the perceived effort (everything feels harder).

2) In the warmer temps, a significant amount of blood flow is redirected from the working muscles to the skin in order to cool the body. Cooling (which is very important to the health of your body - your organs don't want to overheat!) happens from sweating and evaporation. Therefore, less blood is available to transport oxygen to the working muscles. Less oxygen in the heat is similar to training at altitude. But in humid conditions, the air is full of water vapor and it can't hold any more so sweat has a difficult time evaporating (which means it can't cool you like it would be able to do in low humidity).

3) Dehydration increases in hot conditions. When you are dehydrated, you lose blood volume which causes your blood to get thicker. This makes it harder for your heart to supply blood to your muscles. As a result, your heart has to work even harder to pump that blood. Additionally, when fluid levels drop, you have a harder time controlling body temperature which causes the core temperature to rise even faster.

4) You DO NOT lose sodium without fluids. Dehydration comes from fluid loss - not from sodium loss. If you are simply focusing on sodium and carbs (salt tabs, gels and chews) but not drinking enough water each hour, the sodium and carbs will not do anything to help you avoid dehydration. You must drink enough of a well-formulated sport drink to properly keep yourself hydrated.

The bottom line is that the harder you work in the heat, the more heat is generated from the working muscles. Blood in your body competes for the working muscles (energy), the skin (to cool you) and the gut (aid in absorption and digestion of calories). The greater the metabolic heat production, the more energy is needed to cool the body (top priority to prevent you from overheating) - which means more stress on the cardiovascular system. Heat stress also causes an increase in fluid, electrolyte and glycogen loss (which is why pacing is critical) but the heat impacts the ability to effectively digest and absorb calories and fluids. Thus the greater risk of GI issues in higher heat environments.

As you prepare yourself mentally for your upcoming long distance event, keep in mind that working at a higher effort than your body can dissipate heat is going to produce a build-up of internal heat.

• Create a race strategy that will allow you to use your fitness in a smart way.
• Your fastest performance is the one where you minimize a massive slow down.
• Navigate the conditions you are given on the day, don't chase a PR or metrics. Listen to your body.
• Focus on what you can control. Make sure to "check-in" with yourself and respond accordingly.
• Take walk breaks (reset breaks) when you run. The longer you let the heat build up, the greater the slow down (and greater risk of GI issues).
• Back off the effort. Start out conservatively to minimize the risk of irreversible heat stress. Save your heart beats.
• Go in with no expectations. Race your own race.
• Go into the event well-hydrated and fueled so you are in the best state of health possible to perform in the race conditions. Have a plan - don't just figure things out as you go along.
• Fuel and hydrate consistently and frequently. Moderate amounts of fluids consumed frequently will digest and absorb easier than large or tiny amounts consumed periodically. 
• Prioritize liquids over solids for easier digestion. As a general rule, the higher the carbohydrate content (and fat/protein) and lower the fluid intake, the slower the absorption rate.
• Focus on the process. Think of the race as a project, checking off to-do's and overcoming obstacles as you go through each mile.
• Keep yourself cool on the bike so you can start the run with a slightly lower (or normal) core body temperature. Use water from aid stations to douse the body.
• Your mour muscles demand more fuel (glycogen) in hot conditions. Muscles are more taxed which can affect efficiency and can also cause greater tissue damage.
• On the run, your stomach can only empty about 5-7 ounces of fluid every 15 minutes. If you drink more than you can empty from your stomach, you will risk a sloshy stomach. Also, if you only drink water, you risk diluting sodium in the blood. Make sure to rely on a sport drink throughout the race (that’s why I also suggest to wear a hydration belt on the run) and use water only for sipping and cooling.
• Use ice in your hands, on your head, around your neck and near your groin to help with cooling. Also use a cooling towel.
• Minimize the risk of a sunburn by using sunscreen.
• Wear a hydration belt with your sport drinks on hand so you can keep to your own drinking schedule.
• The harder the effort, the more your body temp will increase as more heat is being generated. The harder you push, the greater the increase in heat production. You will know when your body temp is increasing because you will feel yourself getting warmer. Control your effort to better manage your body temp throughout the entire race.
• Look for shaded areas on the course to avoid running in the direct sunlight.
• If you feel overly hot, dizzy or chills. Stop immediately, sit down and get yourself cooled.

If you found this information helpful and you'd like to learn more about sport nutrition (like should you concentrate your bottles during a race, how do I fuel before a long distance triathlon and more?) check out our team membership. 

Sport Nutrition 101 - making a case for sport drinks

If you are a long distance athlete, you've likely experiences several pronounced and uncomfortable symptoms related to unsuccessful fueling/hydration methods. Headache, dehydration, swelling, bloating, sleepiness, lethargy, lack of appetite, nausea, chills, fatigue, deep muscle aches, moodiness and dizziness are not just performance limiting but they are also extremely risky for your overall health. 

Proper fueling during intense or long duration exercise can help you sustain a desirable effort to maximize training adaptations. 

Proper fueling/hydration also minimizes the stress load to help keep your body in better health.

Proper fueling/hydration in training also helps you practice fueling strategies for competition as you can train the gut to tolerate nutrition while exercise at various intensities.

Contrary to the opinion of other nutrition experts, I'm a huge proponent of prioritizing sport drinks during training. I've also had great success prioritizing liquid calories during long distance training (for myself and for the hundreds of athletes that have consulted with me on sport nutrition).

If you are training for a long-distance event (90+ minutes) or training intensely in the heat for 60+ minutes, a sport drink provides a practical and easy way to obtain fluids, electrolytes and carbohydrates, in the right formulation to optimize digestion and absorption. Because you will always need to consume fluid when you train in the heat, a sport drink makes the most sense as the most practical, convenient and easy-to-replicate source to meet your fluid, sodium and carbohydrate needs.
Most sport drinks are very safe and effective but are often misused or neglected – especially in the heat.

Let's learn a bit more about sport drinks and clear up any confusion around sport nutrition products. 

Sport Drink Formulation
For a sports drink to work effectively, it must have the same or less than osmolality of blood. As a reference, blood plasma has an osmolality of 280-300 milliosmoles per kilogram and a bottle of Gatorade has an osmolality of ~330 mOsm/kg. A sports drinks osmolality (Iso-, hyper- or hypotonic) is dependent on the carbohydrate type (ex. glucose, fructose, maltodextrin) and concentration (grams) in a solution (fluid ounces) – in other words, how quickly it can absorb into your blood stream. If a drink’s osmolality is greater than the blood’s (concentrated or hypertonic), liquid will be pulled from the blood and into the intestine to equalize the two concentrations – this net movement of water is theoretically dehydrating. A iso- or hypotonic drink, in contrast, will provide a favorable osmotic gradient so that water diffuses into the cells. If you fail to replace the fluids and electrolytes (sodium) lost in sweat, a cascade of negative events occurs, such as a rise in osmolality, a drop in blood pressure and an increase in heart rate. In contrast, if you drink too much water too quickly and don’t consume drinks with adequate sodium, sodium levels will drop as body water levels rise, causing cells to swell. The tonicity of your sport nutrition is extremely important and likely the main contributor to GI issues, dehydration and early fatigue/bonking. The liquid component is very important and why so many athletes experience issues with only consuming solid food, gels and chews (especially when running). 
Takeaway: 
-Hypotonic - lower concentration of fluid, sugars and salt than the blood. Fast absorption into the bloodstream for quick hydration and electrolyte release. Ideal when you need to hydrate quickly and are not trying to maximize carbohydrate consumption (example during high intensity running, running off the bike and post workout).
-Isotonic - similar concentration of fluids, sugars and salt to blood. When your focus is more on carbohydrate delivery than on hydration/sodium. Because the energy and electrolyte release is slower, a isotonic beverage requires more time to get across the gut wall. This is ideal for long bike rides. An isotonic beverage would work well for a high intensity and/or moderate length bike workout, a swim session and low intensity longer runs. 
-Hypertonic - higher concentration of fluids, sugars and salt to blood. Because of the slow absorption rate, it's not advised to rely solely on chews/gels/bars during your workout. Concentrating your drinks (ex. multi-hour bottle of sport nutrition) is a culprit of Gi issues, nausea and feeling extra thirsty as your body has to move water from the bloodstream to the intestines to dilute fluids before absorbing them. A hypertonic beverage is ideal post workout when you are trying to maximize carbohydrate intake. 

What about Juice, Coconut Water or making my own sport drink?
Because fructose uses a different intestinal transporter compared to glucose and once in the bloodstream, has to be taken up by the liver to be processed into a usable fuel source for the muscles (which can take up to 90 minutes), juices are not recommended as a "sport drink" during exercise.

Although coconut water contains calcium, phosphorus and magnesium (electrolytes found in sweat), sodium and chloride are the major electrolytes because they reside in the extracellular fluid. Compared to a sugar-rich hydration beverage, coconut water is a safe and natural option to occassionally enjoy as an alternative to water. However, to sustain moderate to high-intensity exercise for longer than 90-minutes, the body depends on ingested carbohydrates and sodium – both of which lack in appropriate amounts in coconut water. Additionally, if you are paying extra for coconut water to increase your daily potassium intake, look no further than the produce aisle – a large potato contains 1553 mg of potassium! If you enjoy the taste of coconut water over plain water, choose it for light activity. But to prevent dehydration, replace lost electrolytes and provide the muscles with carbohydrates, a well-formulated sport drink is encouraged. In all other situations, plain water should be your go-to hydration beverage.

As for making your own sport drink - leave it to sport nutrition companies. Instead, make your breakfast, lunch and dinner as you can get more bang from your buck by preparing your meals instead of being a chemist in your kitchen. 

Gels, Bars and Chews
Gels, bars and chews are highly concentrated, portable sources of carbohydrates that are easy to consume during exercise but they lack the fluid and electrolytes that you’d find in a sport drink and are not in the right formulation by themselves to be easily digested and absorbed. Same goes for salt pills. Most gels and chews contain around 100 calories (or 25g of carbs) per serving. More concentrated in carbohydrates compared to a sport drink, gels and chews must be consumed with water to encourage gastric emptying. For every 25g of carbohydrates, at least 12-16 ounce of water should be consumed. Athletes may prefer to dilute a gel into a flask or bottle of water to create a more dilute concentration. Considerably low in sodium (50-100mg), gels and chews are ineffective to replenish sodium lost in sweat. Remember, your fluid, sodium and carb intake will be for nothing if it’s just sloshing around in your gut. As a refresher, scroll back up to re-read about the tonicity of a sport drink and how complicated fueling/hydration becomes when you try to meet your sodium, fluid and carbohydrate needs with different sources. 

This doesn’t mean that you can't consume solid food or a gel or chews during long distance training, but to minimize GI issues and to simplify sport nutrition, I strongly advise to prioritize liquid sport drinks when you train (and race) and use chews/swig of gel for a central nervous system pick-me-up and bars/solid food to keep the tummy happy.

Digestion and Absorption

When applying the topic of sport nutrition, it's important to understand that just because you are consuming carbohydrates, sodium and water, this doesn't mean that your muscles are receiving what you are consuming. If a product is not consumed properly (or formulated properly when mixed), it'll simply hang around in the gut - causing bloating, a sloshy stomach, heart burn, belching, vomiting, gas and/or diarrhea. fluid ingestion. This can further lead to dehydration and glycogen depletion.

Water is absorbed in the small intestines and by the time it enters the large intestines, roughly 80% absorption has occurred. The rate of gastric emptying and intestinal absorption are dependent on the volume and formulation of the beverage. The greater the concentration, the greater the osmolality. This is why you should never concentrate your sport drink – like putting 400-600 calories (2 or 3 hours worth of calories) in one bottle that only has 28 ounces of fluid. When you drink water, there’s a drive for the water to dilute the blood (water moves toward blood) but if you drink a more concentrated beverage than blood, like a hypertonic sport drink or soda or juice, water will move from inside the bloodstream and into the gut – which is dehydrating. The inclusion of electrolytes and glucose in a beverage promotes retention of fluids. When you add a little sugar with sodium (as in a sport drink), you can pull a great amount of water across the small intestines, optimizing water absorption. To help with fluid and electrolyte loss, it's not just about the carbs. You also need to ingest water and electrolytes from a sport drink to keep plasma volume at normal levels. 

There's also an added benefit of a sport drink having multiple carbohydrates for better digestion and absorption but I'll save that for another blog. 

With all this in mind, there are several reputable sport nutrition companies out there to help meet your needs. Here are a few of my favorite sport drinks: 

Swim and Run: 
-Skratch
-Clif hydration
-Fluid
-NBS Carbo-hydration
-Base
-Nuun endurnace 
-Osmo
-EFS

(Don't forget to wear a hydration pack/belt to make it easy to fuel/hydrate when you run. My go-to is Naked)

Bike: 
-Infinit (no protein/fat added)
-Carborocket
-Maurten 320
-Skratch superfuel 

What else should you look for in a sport drink? 

• Simple ingredients - carbohydrate, sodium, natural flavors, preservative (ex. citric acid). 
• Taste - vary the flavors of your sport drink. If you don't like the flavor or texture, you probably won't drink enough of it. If you love it and consume it too often/frequently, you may experience taste bud fatigue and dread it on race day. Consider refreshing and light-tasting flavors especially for the later half of longer workouts. 
• Texture - A sport drink should feel hydrating. If it leaves a funny taste in your mouth or if it's difficult to consume, it's not the right drink for you. 
• Avoid caffeine, protein, fat and other "boosters" in your drink. If you need a boost, get it from an outside source so that you aren't stuck with those added products in your drink (as many times they can cause GI distress). 
• Reach out to a sport dietitian for help. Finding and utilizing sport nutrition is a science and involves a bit of trial and error. Take away the guessing and reach out for help.

What you need to know about hot weather sport nutrition

You may be able to get away with haphazard fueling and hydration strategies in the cold winter months but if you are experiencing warmer temps, now is not the time to "wing it" when it comes to utilizing sport nutrition during your long workouts.

If you've ever struggled with understanding your carbohydrate, sodium and fluid needs during a long workout, you've likely experiences several pronounced, uncomfortable and performance-limiting symptoms related to underfueling, overfueling, dehydration and overhydration such as headache, no urge to urinate, sleepiness, lack of appetite, nausea, bloating, fatigue, muscle aches, moodiness and dizziness.

Proper fueling during intense or long duration exercise helps you sustain a desirable effort to maximize training adaptations. You can also practice fueling strategies for competition and train the gut to tolerate nutrition while exercise at various intensities.

Contrary to the opinion of other nutrition experts, I'm a huge proponent of prioritizing sport drinks during training. I've also had great success prioritizing liquid calories during long distance training (for myself and for the hundreds of athletes that have reached out to me for sport nutrition consulting). 

If you are training for a long-distance event (90+ minutes) or training intensely in the heat for 60+ minutes, a sport drink provides a practical and easy way to obtain fluids, electrolytes and carbohydrates, in the right formulation to optimize digestion and absorption. Sport drinks are very safe and effective but are often misused or neglected – especially in the heat.

Sport Drink Formulation
For a sports drink to work effectively, it must have the same or less than osmolality of blood. As a reference, blood plasma has an osmolality of 280-300 milliosmoles per kilogram and a bottle of Gatorade has an osmolality of ~330 mOsm/kg. A sports drinks osmolality (Iso-, hyper- or hypotonic) is dependent on the carbohydrate type (ex. glucose, fructose, maltodextrin) and concentration (grams) in a solution (fluid ounces) – in other words, how quickly it can absorb into your blood stream. If a drink’s osmolality is greater than the blood’s (concentrated or hypertonic), liquid will be pulled from the blood and into the intestine to equalize the two concentrations – this net movement of water is theoretically dehydrating. A iso or hypotonic drink, in contrast, will provide a favorable osmotic gradient so that water diffuses into the cells. If you fail to replace the fluids and electrolytes (sodium) lost in sweat, a cascade of negative events occurs, such as a rise in osmolality, a drop in blood pressure and an increase in heart rate. In contrast, if you drink too much water too quickly and don’t consume drinks with adequate sodium, sodium levels will drop as body water levels rise, causing cells to swell.

What about Juice and Coconut Water?
Because fructose uses a different intestinal transporter compared to glucose and once in the bloodstream, has to be taken up by the liver to be processed into a usable fuel source for the muscles (which can take up to 90 minutes), juices are not recommended as a "sport drink" during exercise.

Although coconut water contains calcium, phosphorus and magnesium (electrolytes found in sweat), sodium and chloride are the major electrolytes because they reside in the extracellular fluid. Compared to a sugar-rich hydration beverage, coconut water is a safe and natural option to occassionally enjoy as an alternative to water. However, to sustain moderate to high-intensity exercise for longer than 90-minutes, the body depends on ingested carbohydrates and sodium – both of which lack in appropriate amounts in coconut water. Additionally, if you are paying extra for coconut water to increase your daily potassium intake, look no further than the produce aisle – a large potato contains 1553 mg of potassium! If you enjoy the taste of coconut water over plain water, choose it for light activity. But to prevent dehydration, replace lost electrolytes and provide the muscles with carbohydrates, a well-formulated sport drink is encouraged. In all other situations, plain water should be your go-to hydration beverage.

Gels, Bars and Chews
Gels, bars and chews are highly concentrated, portable sources of carbohydrates that are easy to consume during exercise but they lack the fluid and electrolytes that you’d find in a sport drink and are not in the right formulation by themselves to be easily digested and absorbed. Same goes for salt pills. Most gels and chews contain around 100 calories (or 25g of carbs) per serving. More concentrated in carbohydrates compared to a sport drink, gels and chews must be consumed with water to encourage gastric emptying. For every 25g of carbohydrates, at least 12-16 ounce of water should be consumed. Athletes may prefer to dilute a gel into a flask or bottle of water to create a more dilute concentration. Considerably low in sodium (50-100mg), gels and chews are ineffective to replenish sodium lost in sweat. Remember, your fluid, sodium and carb intake will be for nothing if it’s just sloshing around in your gut.
 
This doesn’t mean that you can't consume solid food or a gel or chews during long distance training, but to minimize GI issues and to simplify sport nutrition, I strongly advise to prioritize liquid sport drinks when you train (and race) and use chews for a central nervous system pick-me-up and bars/solid food to keep the tummy happy.

Digestion and Absorption 

When applying the topic of sport nutrition, it's important to understand that just because you are consuming carbohydrates, sodium and water, this doesn't mean that your muscles are receiving what you are consuming. If a product is not consumed properly (or formulated properly when mixed), it'll simply hang around in the gut - causing bloating, a sloshy stomach, heart burn, belching, vomiting, gas and/or diarrhea. fluid ingestion. This can further lead to dehydration and glycogen depletion.

Water is absorbed in the small intestines and by the time it enters the large intestines, roughly 80% absorption has occurred. The rate of gastric emptying and intestinal absorption are dependent on the volume and formulation of the beverage. The greater the concentration, the greater the osmolality. This is why you should never concentrate your sport drink – like putting 400-600 calories (2 or 3 hours worth of calories) in one bottle that only has 28 ounces of fluid. When you drink water, there’s a drive for the water to dilute the blood (water moves toward blood) but if you drink a more concentrated beverage than blood, like a hypertonic sport drink or soda or juice, water will move from inside the bloodstream and into the gut – which is dehydrating. The inclusion of electrolytes and glucose in a beverage promotes retention of fluids. When you add a little sugar with sodium (as in a sport drink), you can pull a great amount of water across the small intestines, optimizing water absorption. To help with fluid and electrolyte loss, it's not just about the carbs. You also need to ingest water and electrolytes from a sport drink to keep plasma volume at normal levels. 

Here's a snippet of a presentation I gave to the Trimarni coaching team on the topic of warm weather hydration and fueling.

Don't wait until a setback occurs to appreciate the power of sport nutrition and how a sport drink can enhance performance, protect your immune system and promote quick recovery.

Warm weather training and appetite loss

A hearty bowl of stew in the winter and a refreshingly cold bowl of fruit in the summer.
Have you noticed how your appetite changes based on the season?

This change is partly as a result of the body needing less calories to function at an optimal body temperature - less energy is needed to maintain homeostasis. Even though in the heat, the body slows down a bit to try to conserve energy to not overheat, if you are an athlete who trains high volume/intensity and you only listen to your appetite to direct you when to (or not to) eat, your loss of appetite can result in a massive energy deficit. While you may think that this energy deficit will help with weight loss/body composition changes, training in an extreme energy deficiency affects normal body functioning, which can affect metabolism, immunity, heart health, bone health, menstruation, endocrine health, recovery, muscle strength and power and mood changes.

Another reason for a loss of appetite in the heat relates to the act of digesting food generates heat. If your body temp is high, your body will suppress the appetite in an effort to reduce the work load until your body temp returns to normal. This is not a good thing when you are in need of nutrition post workout to replenish and repair.

In hot weather, you may have noticed that you are more likely to desire fluids over solid food or maybe you have no appetite for anything. In these scenarios, a cold smoothie or pre-made recovery beverage is often the gold star post-workout drink so that you can drink your calories (and sodium) instead of chewing them. Be careful not to overhydrate on plain water, especially when you've lost a considerable amount of sodium in your sweat.

Tip: If making your own smoothie, follow this order of ingredients to make the perfect consistency smoothie: Liquids, soft foods, powders, frozen foods, then sticky ingredients.

A few other tips to help stimulate your appetite post workout - cool yourself as quick as possible -either with ice packs or cooling towels or in a cold shower. You should notice that when your body temp returns to normal, the appetite quickly increases. Post workout, start your recovery with liquids and light foods (easy to digest) instead of not eating or attempting to eat a heavy meal. Aim for small snacks and meals throughout the day. If you are experiencing a strong headache or nausea after your workout, in addition to loss of appetite, this is likely a sign of dehydration and that your workout hydration strategies are inadequate.

Just because you don't have a subjective desire appetite to eat, this doesn't mean that your body is not in need of calories. To repay your body, who worked extremely hard to help you complete a given workout, figure out the best foods/drinks and strategies to refuel, rehydrate and recover after your hot-weather workouts. In this scenario, not eating because you don't feel hungry can be damaging to your performance and health. 

Tips for adjusting to warm weather workouts

The warm weather is finally here!

While it's great that we no longer have to bundle-up in layers of clothing before an outdoor workout, there is great physiological strain imposed by training in hot conditions.

In a recent interview with the Epson Salt Council, I provided my 5 tips for adjusting to warm weather workouts.

Since this topic is one that I discuss quite often with my nutrition and coaching athlete, here are a few blog posts specifically discussing the topic of hot weather training/racing:

Acclimatization - 8/09

Perfect Cooling Towel Review - 9/15


Challenge Williamsburg Race Report - Temp Real Feel 124 degrees - 6/15

Simple Sport Nutrition tweaks - Swim 8/16

Simple Sport Nutrition tweaks - Bike 8/16

Simple Sport Nutrition tweaks - 8/16