running nutrition

Carbohydrate Intake and Uptake

Nicole Lowe McBrideLeave a comment

Carbohydrates are the energy source most runners use to fuel their training and their racing. Wait? most runners. That’s right there are some runners out there who use fats, protein, and even nothing. But this blog is about the carbohydrates. Carbohydrates are broken down into glucose, which is what our bodies burn to fuel our muscles, nerves, and brains. Our bodies can store glucose as glycogen in our muscles, but it’s limited. When we run out, we hit the infamous WALL, if we haven’t properly fueled. Our blood also has glucose floating around. Maintaining our blood sugar level is how we prevent hitting, or reduce the impact of, the wall.

Ultrarunners and even some marathon runners struggle with GI issues and are constantly on the look out for ways to optimize their fueling strategy and minimize GI distress. It seems like a never ending cycle, and I’m not here to tell you there’s a way to end it, but there are different things to experiment with and thereby, possibly minimize your discomfort. In our efforts to maintain our blood sugar level and avoid the wall, we may overload on the carbs which causes sloshing, cramps, bloating, and other nasty things in our stomachs.

So the trick to minimizing GI issues, is knowing how much to intake to maximize uptake, but not overload the system. This blog is also for those who don’t suffer from GI issues, since we’re going to look at how much carbohydrate a body can uptake.

Depending on the intensity you’re running at, you’re going to run out of glycogen stores withing about 90 minutes to three hours as an average endurance runner. To maintain your blood sugar levels you need to start taking carbs in right before you begin your race or a long training run. Then, you’ll need to take more at regular intervals to meet that 60-90 grams per hour.

What we know is that regardless of how many grams of carbohydrates you intake, your body can only uptake between 60-90 grams an hour. What determines whether it’s 60 or 90 is the type of carbohydrate your taking in. Your body can process about 60 grams of glucose an hour. So if all you’re getting is glucose, don’t try to put more than 60 grams an hour in.

To get to the 90 grams an hour, you have to combine the 60 grams of glucose with 30 grams of fructose (although sucrose is a combination of fructose and glucose it’s not processed the same so avoid sucrose as a source of fuel). The reason your body can handle the 90 grams of carb processing is because glucose and fructose take different paths to be absorbed by your body.

Sixty grams of glucose produces about 232 calories. Thirty grams of fructose produces about 120 calories. For a grand total of 352 calories replaced during every hour if you play your cards right.

Dextrose and Maltodextrin are made from starches, but are absorbed like glucose. This is nice to know because fructose is very sweet and sometimes sweet things become intolerable during a race. Maltodextrin and Dextrose are not as sweet as glucose and so they can be combined with fructose to get the same benefit of the 90 grams of carbs.

Water intake with the carbs is important. Your digestive system needs water to break things down and get it into your blood stream to be used. Without water, it just sits in your stomach (which is why dehydration causes GI issues). If you put more than the 60-90 grams in an hour, your body is not going to be able to absorb them and they will just sit in your stomach causing problems.

What if you’re feeling depleted, but can’t stomach more food/gels/chews? You can rinse your mouth with a carbohydrate rich drink and spit it out. This will make your brain think that carbs are on the way and give you a little boost for a little bit, but unless your close to the finish line, you still need to figure out your GI issue.

 

How many carbs do I burn when running?

Nicole Lowe McBride1 Comment

Carbohydrates are one source of fuel our bodies use to provide energy for our daily activities and for our runs. Fat is the other source of fuel our bodies use. Carbohydrates have to be replaced during training and racing, but fats don’t. How much and how quickly we burn through carbohydrates and fats depends on a variety of factors. Understanding how many calories we burn and where it comes from can help us dial in our nutrition plan for race day and for training.

When we run fast and for shorter distances we burn mostly carbohydrates. As our distance increases and our pace decreases we begin to use fat as a fuel source too. We begin to use fat at slower long distance events because we have a lot of energy stored up in fat, even very thin people. Fat takes more oxygen to burn so if you’re running hard, it’s not a good source of energy. Fat also takes longer to burn, so if you’re running fast, it’s not a good source. If you’re running a 5k-half marathon, you’re tapping into your carbohydrate stores and burning very little fat.

This is the core of the belief that endurance athletes can perform well on a low carbohydrate diet. The problem comes when the same athlete tries to push hard and go fast. I raced and trained on a low carbohydrate diet for 18 months and was fine, unless I wanted to push my limits and then…I died. Despite being low carb (under 50 g a day), my body still could not burn fat fast enough to sustain hard effort. So I switched back to a higher carbohydrate diet.

One way to figure out the ratio of carb to fat that you are burning is to use your heart rate. To do this you need to know what your maximum heart rate is (220- your age. This is a guestimate). During your run, check your heart rate. At 70 percent of your max heart rate, about 50 percent of your fuel comes from carbohydrates. At 75-80 percent of your max, it increases to 65% carbohydrate.

So a person who is 150 lbs, running at a 7 mph pace (8.5 min/mile) for one hour burns about 782 calories. If that puts the person at 70% heart rate that’s 391 calories from carbohydrate. At 75-80% heart rate that’s, 508 calories from carbohydrates. The same person running at a 5 mph pace (12min/mile) burns 544. Because they are going slower, the amount of calories coming from carbs is less and the amount coming from fats is more.

The American Council on Exercise has a physical activity calorie counter that is based on your body weight, duration of exercise, and intensity. You can find it here. There are a bunch of different tools there to try out, if you’re curious.

Once you know how many calories per hour you’re burning on average during your runs, you can begin to understand and build a strategy for resupplying your body with those calories. Your body cannot process enough food to be able to make up for the amount of calories lost through carbohydrate burn if you maintain a high intensity. The most you can hope to process per hour is about 352 calories. We’ll get into how to maximize that in the next post.

 

 

Superfoods?

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superfoods

A superfood is something that is nutritionally dense. Many are plant based, but things like salmon also have made the list. What does it really mean to be a superfood? Is there any research or is it a marketing tool?

There isn’t a set criteria to determine which foods are superfoods. Foods on the superfood list have extra-large doses of vitamins and minerals that can help ward of diseases and support a longer, healthier life, but so do fruits and veggies not on the list. Many of the superfoods are high in antioxidants shown to reduce risk of cancer; healthy fats to reduce the risk of heart disease; fiber which helps with diabetes and digestive problems; or phytochemicals which have many health benefits such as reducing certain heart conditions in young women.

What’s on the list?

Blueberries because they are rich in vitamins, fiber, and phytochemicals (but many other berries are too). Kiwifruit is very similar to berries in its nutritional value. It also contains serotonin, which is linked to depression and sleep.

Beans and whole grains are on the list because of their fiber content, loads of vitamins and minerals which are typically absent in American diets such as manganese. Quinoa is usually lumped in this group but it’s not a grain. It is a great source of protein, vitamins, minerals, fiber and antioxidants.

Nuts and seeds have high levels of minerals and healthy fats. You do have to go easy on them because they are high in calorie, but don’t cut them out of your diet.

Kale and other dark leafy greens such as collards, swiss chard, mustards, spinach, cabbages, and broccoli. These are great sources of vitamin A, C, and K. They also contain fiber, calcium and other minerals. Sweet potatoes and squashes can be thrown into this mix too. Their added benefit is they are sweet and don’t need anything added to them to be loved.

You’ve got salmon, sardines, and mackerel on the list because of their omega-3 fatty acids, which you can also get from many nuts (walnuts are the best) and seeds (flax and chia) as well as vegetables. Omega-3 fatty acids lower your risk of heart disease.

Exotic fruits such as, acai berry, noni fruit, dragon fruit, rambutan and pomegranate, also end up on the list. It’s always fun to try new fruits and veggies, but if you think you’re getting something other superfoods don’t have your wrong.

I’ve also seen the following on the superfood list: goji berries, maca powder, cacao powder, hemp seeds, chia seeds, apples, cranberries, cauliflower, pumpkin, beets, lentils, papaya, seaweed, tomatoes, ginger, garlic, pineapple, spirulina (algae), and avocado, just to name a few.

Bottom line is scientist don’t use the term superfoods to describe any food. It appears that the term has been coined by marketing peeps. The best advice is to reduce the amount of processed food you eat. Buy whole grains, raw sugar, whole fruits and veggies. Eat different colored fruit and veggies.

Making the Leap to the Ultra-World: Food

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making the leap 5

Fueling your body during a run is, as I’m sure you can imagine, a really big deal. Many runners use gu during events of a half marathon, and close to 90% use some form of sports energy during the marathon.

For an ultra, mishandling your food can destroy your event. Trial and error is the only way to figure out what is going to work for you. The one factor that is the same regardless of how you fuel is using small amounts frequently rather than eating a larger amount. A quarter of a peanut butter and jelly sandwich is going to be easier than the whole sandwich. The other rule, which cuts across all aspects of running, is train with it before you race with it. After that, there are four approaches to maintaining your energy during an ultra.

First, is to use sports energy options, such as gu, stinger, or hammer gel, throughout the run. There are a few ultrarunners who do this. Sports energy delivers a fast supply of sugar, which is what your muscles are burning. Personally, I’ve never been able to do it this way and none of my runners have been able to do this. The gels and such become torture to get down. Even if you like them, by mile 75, you won’t. Your body needs a little more than just sugar when you are moving for more than 24 hours.  That’s where the other approaches come in.

Second, is to use a mix of sports energy and regular food. A lot of the runners I work with, even marathoners, choose this option because it gives them quick energy and a more sustained slow burn energy. To implement this strategy, find some foods you think are easy to digest such as fruits, potato chips, candy, cookies. These still give you the carbs you need, but they take a bit longer to get to the muscles. You can throw in small amounts of protein as well, which slows the breakdown of the muscles in the later part of the run.  Be cautious and chose easy to digest proteins such as nut butters and protein bars or drinks.

Third, is all regular food. I use solid regular food throughout my runs. You want a mix, again, of slower and faster digesting items. With solid foods, you need to keep in mind it takes longer to digest so you will need to eat before you need the energy, rather than when you are starving. The other problem with waiting until you are hungry to eat, is you over eat. Over eating can cause stomach irritation.

Fourth, is low carbohydrate. Low carb is a life style not merely used during an event. It requires the runner to stay below a certain amount of grams of carbs everyday, which allows them to burn fat rather than the glycogen in their muscles. Fat is an excellent source of energy. However, being low carb also requires the consumption of a lot of fats as well. Consuming a lot of fats is not necessarily bad. The research is a mixed. The type of fats a person consumes does make a difference. Anyway, low carb runners have to bring their own food (same as vegan runners). In theory, they don’t have to consume many calories because they are burning the fat. That was not my experience. I was low carb for 18 months and found I was not able to consume enough fats to maintain the energy I needed to run ultra-distances. Some low carb runners use a product called Vespa which enhances the body’s ability to burn fat. Others supplement with high doses of sugar at strenuous times (big climbs) during the event to give them the extra boost. The sugar hits their system fast and furious because it doesn’t get it very often.

Regardless of the approach you use, practice during training runs is the key. You have to train your body to digest at the same time it sends energy to muscles. Use trial and error to find what works for you. Keep in mind that it is best to try one thing at a time and to give your body a couple of weeks to decide if it is alright with it. When you introduce a new thing, it may cause some issues at first, but those may go away with continued use.

Fueling for a Race

Nicole Lowe McBride1 Comment

aid station

Providing your body with the energy it needs during a race can be one of the trickiest things to figure out as a runner, but if you plan to run half marathons, marathons or ultras you have to figure it out. There are many fuel options, how do you know which one will work for you? You don’t the only way to figure it out is through trial and error, but where to start.

The various products out there use different types and combinations of sugar such as dextrose, Maltodextrose, and fructose. Some people have a harder time digesting some sugars more than others while running. When you are running, your body’s primary focus is pumping blood (fuel and oxygen) to your muscles. Digestion also takes blood, and your body is reluctant to shuttle much blood away from your muscles, so if you eat something that is difficult to digest or heavy, it will just sit there bouncing around. There are lucky people out there who can eat just about anything while running and never have to worry about it.

There is hope for those of us who cannot. You can train your stomach to digest while running, which brings us back to what to use. Start with asking your fellow runners what they use or go to a running store and ask for suggestions. If you plan to use what is supplied at your goal race, you should be checking their website or emailing the race director prior to the race to find out what that is. You do not want to eat something during a race for the first time.

It doesn’t really matter where you start gu, hammer gel, shot blocks, sports beans, stingers, or waffles. Heck, you can start with real foods that are easy to carry jelly beans, M&M’s, quartered peanut butter and jelly sandwiches, or fruits. The benefit of the manufactured products is that they are made to be easy to digest, which means they require less blood to your stomach to get into your blood.

The other half of the equation is how frequently do you eat while running. For things that are easier to digest you will need to eat them more frequently because they go through your system more quickly. Your body weight and your pace also change how often you must take in fuel. The more you weigh the more you will need to maintain your pace. The faster you run the more you will need to maintain your pace. Runnersconnect.net does have their “Marathon Nutrition Blueprint,” which calculates how many calories you need to take in and when during a race. I’ve never used this, but it is out there if you want to give it a try.

This requires practice. When you go out for your long runs try different fuels and the timing of them. You can try them on shorter runs as well, but the long run is going to give you the best idea. For a shorter run, eat whatever it is five to ten minutes before you start. You may try one and immediately know it will not work for you because of texture, ability to chew it, or nausea. Others may take your body a few runs to adjust to digesting.

Remember to drink water before and after you eat something. It will help with digestion. If you use a sports drink rather than water, keep in mind that it also contains sugar, so you may not need to take something else as frequently.

Low carb is another matter entirely. The central idea behind eating a low carbohydrate diet is that your body can use fat as energy and it has at least 40,000 calories of fat even if you only have 6% body fat. However, like with anything else you have to train your body to use fat as fuel. This requires eating low carb all of the time not just during a run.

Some low carb runners don’t need anything but water and electrolytes to run, especially for the half marathon or the marathon. When you get to ultramarathons, even the low carb runners typically need to eat something. There are a few low carb options out there like Vespa, the almond butter mixes, and a few gels with lower carb counts 26 compared to 100 in gu or hammer.

As a low carb runner, you can use carbs to boost your energy during a race to kick your body into a higher gear for a burst of speed or for climbing a hill. You do need to train with this approach because your body needs to learn how to transition back and forth between burning carbohydrate and glucose.

The bottom line no matter what you chose to fuel your body with while running is to TRAIN YOUR BODY TO USE IT.