Carbohydrate Intake and Uptake

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?

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.

 

 

Protein Intake

We all hear so much about carbohydrates, but we don’t hear a lot about protein. Many runners think that since they’re not trying to gain muscle mass protein isn’t as important. And that is where they would be wrong.

Protein is essential for people who are trying to build muscle mass, but endurance athletes need just as much and ultrarunners may need more. The recommended amount of protein for the average Joe is 0.8 grams per kilogram of body weight. For endurance athletes the recommendation is 1.5-1.7 grams per kilogram of body weight. For ultrarunners, it jumps to 1.8 to 2.0 grams per kilogram of body weight.

Why we need so much protein? because we push our bodies on a regular basis. And we don’t just push them a little bit. We push them beyond what most people call reasonable. We need the protein to repair those micro tears that occur through our regular training. We need the protein to strengthen our muscles when we’re doing our weight lifting throughout the week. Finally, protein is converted into energy by our bodies, requiring us to take in a little more to make sure we have enough to repair and strengthen.

Our protein intake should be spread out over the day. You’re body can only process and use so much protein at a time so taking more than 25 grams at one time doesn’t do you a whole lot of good. Eating six smaller meals throughout the day rather than three large meals, makes spreading protein out much easier. You don’t have to use protein shakes either. There are many healthy sources of protein to fit any eating lifestyle. Obtaining all of your protein from animal sources has its health consequences. If you’re vegetarian or vegan, you need to make sure you are getting your protein from a variety of sources to ensure you’re getting all nine essential amino acids (there are more amino acids, but your body can produce all but nine of them).

Another myth is that you need to take in so much protein within a specific length of time after your workouts because your body is primed for absorption. This is true when it comes to carbohydrates, but not for protein. There isn’t a do or die time frame for getting it in after a workout. That said, it’s best to get it in as soon as you can so you don’t get behind in your intake for the day. Also, protein can help with the absorption of carbohydrate after a hard workout. This is only the case when your body is carb depleted. Ever heard of the 4:1 carb to protein ration after a hard workout? It comes from this benefit.

Your body’s ability to absorb protein when it is working, like in a training run or a race, is very limited. Most people are fine with about 1% of their fuel intake being protein. Much more beyond that and you could suffer some GI issues because protein is harder for your body to break down, which means it could be sitting in your stomach sloshing around for some time.

Running Preggers: Baby Belly Support

A maternity belt is going to be a must have for most running moms-to-be as they near the third trimester. Many women even with the support of a maternity belt decide to stop running during the third trimester because it becomes too uncomfortable. There is no shame in taking a brake during your last weeks of pregnancy ladies.

Keep in mind a belly band and a maternity belt are different. If you’re running, a belly band isn’t going to help support your baby belly. The band allows you to continue to wear your pre pregnancy clothing for a longer time and delays the purchase of maternity clothing. It will cover your belly as your shirt creeps up and it will hold your pants up when you leave them unbuttoned and the zipper more and more down as baby grows.

A maternity belt will help lift some of the baby belly weight up and distribute it more evenly across your back and hips. You can start wearing one whenever you want. I started wearing mine around week 27. I actually tried a bit before then, but found that my belly wasn’t big enough to make any difference. I should have bought a size small rather than a medium, which would have allowed me to wear it sooner.

When you reach the third trimester, baby is about 2 pounds, still pretty small, but over the next 13 weeks baby will add on 4.5-5 pounds, and maybe a little more. Running with a medicine ball attached to your abs that increases in weight every week is tough. Many women begin to feel very tired and have round ligament pain as the uterus grows to its max height and baby’s weight increases. Pelvic pain can be problematic because the hormone relaxin is relaxing those tendons/ligaments holding your pelvis together. You can also have a feeling of increasing downward pressure (not time to exit yet kiddo), which is uncomfortable.

I bought the Gabrialla belt after reading some reviews from other running mamas. Things you want to be aware of when selecting your belt are: first, washability. That thing is going to get sweaty and you’ll want to wash it pretty regularly. Second, regular washing, means you want it to be durable. The third thing to consider is breathability. Being pregnant generates a lot of extra heat, so wearing something around your middle that traps heat in, is not going to work.

The Gabrialla goes around your low back and then under your belly. If you do it up too tight it can push on your bladder. You want it snug and comfortable. My daughter will kick and push at the belt before and after our run, but she is rocked to sleep while we are running. You can wear it over or under your clothing. I wore it over just because I didn’t want to risk any chafing.

I’ve had a few women come and ask me about the maternity  belt when I finish a workout at the gym and I’m always happy to help keep another mom-to-be active and happy.

 

Running Preggers: Clothing issues

Sure, you can just wear larger sizes of clothes, but who really wants to do that? It’s much more fun to show off that baby bump, especially, at the gym, on the trail, or out running on the road. Show the world pregnant women are strong and fit.

The problem is maternity fitnesswear is kinda expensive and then you’re only going to be wearing it for a few months. Every woman and every pregnancy is different and will change what clothes you need and when you need them. If you’re planning on future pregnancies and/or you have extra money (after all the baby purchases), buy the clothes that make you the most comfortable, even if they are a little pricey.

Depending on how you’re carrying your baby (high or low) changes what you may need. If your carrying low, pants and shorts can become a problem before shirts do. If you carry high, shirts are a problem earlier in your pregnancy. By the end, it’s all going to be a problem though. Shorts with drawstrings and longer shirts may be the most cost-effective solution.

Sports bras are another ball game all together. You’re going to need a larger size and you may need to go up a size after that depending on how things play out. If you’re planning to breastfeed your baby, you’ll want to invest in some nursing sports bras, plus their just a bit more comfortable than normal nursing bras.

Sports bras are expensive especially as the size increases and you need more and more support. No one wants the girls bouncing around and when you’re pregnant it can be painful. If you’re going to be breastfeeding, it is probably worth the extra cost to get the higher quality nursing bras that have good support since you’ll be using them for a while. But, don’t get them too early because once your milk comes in you could go up another size. You’ll want to wait about five days postpartum before you get more than one (because you might want one to wear home after the birth).

What’s a woman to do, when you know your bra size is most likely going to change throughout pregnancy and the sports bras are pricey? Double up. Yep, wear two bras. It does create more heat, which can result in a slight heat rash for some women. But I can get two cheaper bras for less than a really high quality supportive one. If the girls were going to stay that size forever, I’d buy the more expensive one, but they’re not.

Another clothing issue you may be lucky enough to experience is chafing. Your higher body temperature and blood volume make you start sweating earlier in your workouts. Add that to your not so great fitting clothing and you’ll be investing in Body Glide or other anti-chafing cream.

Good luck ladies!

Running miles: I’ve been able to maintain the 3 miles a day at a 10:30 pace. I’m 31 weeks three days pregnant. I’m supplementing with the elliptical or stair master for the rest of my aerobic workout.

Running Preggers: Blood Volume

As an endurance athlete you already have a higher blood volume. Having higher blood volume reduces heart rate during exercise, delivers more oxygen to hard working muscles, sends more blood to the skin for cooling, and furnishes a reserve supply of internal fluid so that sweat rates can remain high during exercises. Your blood volume begins to increase after just a single exercise session and then reaches its peak within a few weeks.

Aerobic exercise typically reduces your blood pressure and your resting heart rate. But pregnancy increases your heart rate and makes your blood pressure fluctuate. Your resting heart rate can increase by as much as 15-20 percent during pregnancy.

The increase in blood volume due to cardiovascular fitness is much less than the increase seen for pregnant women. Pregnancy increases your blood volume, in fact it increases by as much as fifty percent. You need this extra blood because you’re providing for your growing child. During your first trimester, your blood is going up, but not a lot because the baby is so small and has small needs. By the second trimester, you may experience dizziness or lightheadedness as your body tries to catch up on the need for more blood. By the third trimester all this extra blood can leave you with swelling in your feet and joints.

Additional side effects of increased blood volume in pregnant women can include an increase in body temperature and sweating. All the extra blood volume can make your veins more visible and larger.

Blood volume also accounts for approximately four pounds of the recommended weight gain for a pregnant woman (25-30 lbs). Other fluids, not including the amniotic fluid, like water add another 4 pounds. The amniotic fluid is about two pounds.

That’s a lot of extra fluid floating around in your system by the time you reach the end of your pregnancy.

Weekly Miles: at 30 weeks pregnant, I’m still running but I’ve had to reduce my miles a lot. I run three miles a day at a ten and a half minute mile. Some days are more comfortable than others. I’m supplementing with the various elliptical machines at the gym to maintain my cardiovascular fitness. As the belly has begun to stick out more, the maternity belt works better and is able to reduce the pressure I was feeling in my pelvis while running.

Keep running mamas!

Running Preggers: Relaxin

I wish I were trying to be cute and leaving the “G” off Relaxing, but Relaxin is a hormone produced in increasing amounts during pregnancy. It’s a necessary hormone, but as an athlete, it’s not something you want in increased amounts. Relaxin is a protein-based hormone found in men and non-pregnant women. Pregnant women have ten times the amount as non-pregnant women.

Relaxin relaxes the blood vessels, ligaments, and tendons in your body. It begins its work in the beginning of pregnancy (before actually) by preventing contractions in the uterine wall and making implantation easier. It allows your blood vessels and arteries to expand to accommodate the extra blood volume. As you’re baby grows and shoves your internal organs into your ribcage you’ll be glad relaxin has made expansion of your abdominal muscles and ribcage possible. What you’ll be most happy about is relaxin ensures that your pelvis will be able to expand not only to accommodate your growing child, but to allow the child to be born.

Relaxed tendons are a problem if you are an athlete. It can be problematic if you’re not an athlete and you just want to go about your day without any pain or discomfort in your joints. Instability in your ankles, hips, and knees is something runners try to minimize and correct through strength training. When you’re pregnant, strength training isn’t going to help and you really, on some level, don’t want it to help because that baby has to exit somehow.

The instability can cause achiness and pain in your joints with just everyday activities, let alone running. Relaxed tendons and ligaments places you at higher risk of injury, even when doing exercises you have been doing for years pre-pregnancy.

What all of this means for pregnant runners is be careful and rethink increasing your miles or the intensity of your running workouts during your pregnancy, especially, during the first and third trimester when relaxin levels are at their highest. You’re also likely to feel increased soreness after runs, especially, in your pelvic girdle, hips, and lower back. Try using a maternity belt to help reduce the pressure of the baby on your pelvic joints.

You’ll likely have to decrease your miles and your pace as your son or daughter grow and their debut approaches. Reducing your miles to prevent injury, especially, an injury that could stop you from getting back to running after baby is born, is a small price to pay. Cross training with low impact exercises, such as swimming and cycling, will become your go to activities at the gym. I know this can be frustrating, but keep in mind it also means you’re closer to holding your little one in your arms.