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How to read an InsideTracker test after a marathon

Four days after my first Boston Marathon and amid my three highest-volume training months ever, I had my blood tested by InsideTracker. I was interested in learning how my body dealt with the physical stress so I took the test about three months after my previous blood draw and recommendations.

As a masters endurance athlete, It’s important for me to understand how my training is affecting my body on the inside. Beyond the pains, soreness and niggles, I want to be able to fully understand the impact of the training stress.

Thanks to InsideTracker, a simple blood draw is analyzed by experts and then customized recommendations are delivered privately to me. After seven tests over the past several years, I have been able to address problem areas (like Vitamin D deficiency), monitor areas that trigger warning signs and refocus my diet.

InsideTracker is recommended for athletes of any skill or experience level, as well as anyone else wanting to learn more about various markers that define their health. To learn more, visit and use my code for 15 percent off.

Consulting with an expert

My curiosity about the changes in the mid-April InsideTracker test went beyond the training and marathon. During our four-day trip to Boston, I deviated from my normal home-cooked meals for restaurants. I made the best efforts to eat healthy but of course my options were somewhat limited.

To help me understand this set of data, I reached out to an expert. Ashley Reaver is a registered dietitian and a certified sports special dietitian who works for InsideTracker. She also operates a virtual private practice focusing on sports nutrition and general wellness. Follow her on Instagram @our.weekly.eats.

Reaver recognized how the stressors of my training cycle and marathon had an impact on my results.

“Your previous test had most of your markers within the optimal zone, which is great,” she explained. “With this test, you just put your body through something amazing, and now we're seeing what that looks like on the inside.”

Here is an excerpted question and answer session with Reaver:

Question: During an athlete's training cycle, when is the best time to get tested? And how are results affected by the changes I mentioned involving recent travel, racing and diet changes?

Reaver: Typically, I recommend testing at two or three different points in the training cycle. I'd say the most important one to test is to get a baseline. Do that when you're not in a really heavy training block or starting to train for a race. Then having a test that can either be in the middle of your training block or after a tough effort, like running the Boston Marathon is a good example, because you can kind of compare where those markers are compared to your baseline and then use that as kind of like an example or template for how your body responds to high levels of stress from training.

Question: That's good to know. When looking at my previous test, the one in January, compared with the new one, what jumped out at you?

Reaver: I'll take an easy one to start. Inflammation is one that definitely had a little bit of a spike there in your HSCRP, which is just a really non-specific marker of inflammation. Endurance events are a lot of strain on our joints. So, typically, we definitely see a spike there. Your white blood cells, which are also in your inflammation group, looks like they continue to drop down a little bit, which also isn't something that's not too surprising. Training, obviously, is a big strain on the system and one of the things that it strains is our immune capabilities. That's a reason why a lot of runners end up getting upper respiratory infections is because their immune system is a little bit compromised through training.

Some of the best things for inflammation are getting a diet that's high in antioxidants. The best ones from food are vitamins A, C and E as well as the mineral selenium. Best sources of vitamin A are going to be from red, orange or yellow fruits and vegetables, as well as dark leafy greens. Vitamin C, citrus is a pretty well known one, but we're at berry season right now, broccoli, bell peppers, kiwi are also great sources. And then vitamin E, similar to vitamin A as a fat soluble vitamin. Vitamin E, you find mostly in nuts and seeds. The best sources of vitamin E are wheatgerm and sunflower seed oil. A Brazil nut a day is the best way to get selenium into your diet.

It’s important, especially during training, to consciously make a selection from each of those categories each day because that helps to boost your body's antioxidant content. Antioxidants are so key in training but also in battling inflammation that comes with that because antioxidants essentially can break the inflammatory cycle. So, when our body responds to either a real invader, like bacteria or a virus or any sort of stress or damage internally, it does that by mounting an inflammatory response. And in that process, that inflammation causes a little bit more damage, which then mounts another inflammatory response, which causes a little more damage and mounts another one. That cycle can really snowball, and that's where antioxidants are so key in the diet is because they can get in there and help to break that inflammatory cycle.

Question: What else did you note?

Reaver: Your creatine kinase is kind of a little bit lower. Creatine kinase is an enzyme that naturally lives in our muscles. Anytime there's muscle damage, it just seeps into the bloodstream. You'll notice that two of your liver enzymes also increased, and that's because they follow a similar pattern to creatine kinase. So, ALT and AST are also found in the muscle. They're primarily found in the liver, but similar to CK, anytime there's muscle damage, we'll typically see these two seep into the bloodstream. You can see that your AST is kind of in the high red level, and the ALT is just in the high but still normal zone. Typically, we'll see a spike in AST first, and then a spike in ALT and then a spike in creatine kinase.

Creatine kinase comes back down pretty quickly, but two liver enzymes can take about seven to 10 days to come back down to normal. But, just something important to note that those two liver enzymes can be elevated due to activity. The third one that's in that group, GGT, is only found in the liver. If there was any real liver damage that came from this, you'd likely see an increase in GGT as well. I think it's pretty safe to say that it's just due to the strain that you put on your body running 26.2 miles a few days before the test.

Question: Good to know. I also noticed was my sodium levels were noticeably lower. Is that specifically due to all the sweat loss during the marathon?

Reaver: Not necessarily. It could be. Sodium and potassium are interesting ones in that they can really change within a couple of minutes based on our hydration status. So, this could be that you lost a fair amount of sweat while running, or it could be that you were really over hydrated, maybe not on race day but going into this test, or adequately hydrated. Maybe you've rehydrated really well. So, sodium is measured as a concentration, so it's something that's going to change depending on how much fluid or volume is in your blood at the time.

Question: Another reason I wanted to get tested now and compare it to January was at the beginning of this year, I removed eggs from my diet. I do egg whites. I've also pretty much gotten rid of dairy, using almond milk. And one thing that struck me was my cholesterol actually went up in this time period. What do you make of that?

Reaver: It looks like the increase came mostly from HDL. Your LDL level is still really, really great. It's very low. I think that we've looked at other athletes’ results after other endurance events, too. People running 100-mile races or doing really crazy bike races. And truthfully, at least what we've seen from those athletes across the board, is a bit of an increase in cholesterol. I don't know if that's because the body is breaking down like triglycerides to use as fuel and maybe the body is repurposing them or something like that. I would say though right after a race is not a good time to look at these metabolic markers because you just put your body kind of through the wringer.

Same thing kind of goes with glucose. Again, it's not a good time to assess changes because those markers are typically ones that, they're responsive to, I'll say that they usually take a longer time to change. But, in the event of some like really serious impact on the body, that they can certainly jut out of line, like way out of where they would usually be. And the other markers, more like your muscle damage or inflammation, things like those, those are better markers because those are ones that we are anticipating changes in and can be kind of used to influence decisions we make in the future. But your metabolic markers after really tough events aren't a good metric, I'll say, like a true metric, which is another reason why getting that baseline during an easier training period is really key, too.

Question: Sure. You mentioned magnesium as a recommendation. In reviewing the data, do you see any worrying signs and what other recommendations do you have?

Reaver: Your cortisol is coming down a bit. It seems like that kind of spikes and drops. That's still something that I would encourage you to focus on. It being down a little bit post-race could just be that your body was channeling fuel into something other than producing cortisol. So, certainly focusing on stress relieving behaviors is key, but also the same physical stress, like sleep and not having enough rest and recovery as well as inadequate calories are something that can cause that cortisol to be high.

I wouldn't worry too much about your glucose, again, just same reason as cholesterol. You just encouraged your body to use a lot of different things for fuel over the course of three or four hours. So, I wouldn't necessarily encourage changes there. Liver enzymes, same with your creatine kinase, are things that, those are things that we would expect to happen based on some muscle damage.

They will go back to normal on their own, typically within 10 days. But, certainly knowing that there was muscle damage from the run, it's important to make sure that you're eating an adequate amount of protein in order to repair that muscle damage. Doesn't have to be a crazy amount but typically, I would say about 1.4 grams per kilogram is a good point for runners to focus on. Running certainly isn't intended to always cause muscle damage, like resistance training as we do still incur quite a bit of muscle damage and we need to make sure that we have the building blocks available for our muscles to repair.

Question: What do you recommend for athletes like myself who now have a good series of the tests over time? When you look at it, how do you analyze and kind of balance the changes in the results over time versus say one, a recent one compared to the previous one taken?

Reaver: We're certainly looking for trends, especially of markers that are maybe in the clinically high or clinically low zone. One blood test, or one data point in either the high or low zones doesn't necessarily indicate that something is really, really wrong, and not really a cause to raise red flags. But trends of things, especially for markers that there isn't necessarily an explanation for, like your RBC magnesium is a good example. That's something that, and your AST, those are things that I would expect to be outside of the normal zone based on knowing that you just ran a marathon before this test.

When analyzing results or interpreting results, it's really important to really consider the context around when those tests were taken. That's why we added those trend lines in there just so you can see an average. There aren't many markers that increase or decrease. That's not even just biomarkers. It could also be weight and heart rate and other metrics in our body that always go in the way that we'd like them to be. Most things, on average, can move in those directions but between tests, sometimes they may go up, they may go down. Just following the trends is the base thing there.

Question: I didn't mention this at the beginning, but while the Boston Marathon has been a goal, it was also a building block to what I'm doing in a week, and that's my first 100K. So my highest three volume months ever in terms of mileage in order were March, April and February of this year. So, probably what you're seeing is also not just that one day run, but just the cumulative 12ish weeks of some pretty hardcore training.

Reaver: Definitely. Truthfully, I think that that probably gives a little more credence or reason to emphasize some of the markers that were out of range. Just knowing that that run was kind of like a regular day in your training, it wasn't the craziest thing that you've done and it's not really outside of your norm. So, certainly knowing that, I would apply those recommendations as much as possible because this is kind of a true, probably a true place of where your body is now. Not so much based on what happened that one day.

Question: This also gets into the need for athletes to have real breaks between training cycles like this one. So, what would you recommend, and I know everybody's different, but after a 16- to 20-week training cycle, what does an athlete's body really need to recover and reset before the next training block begins?

Reaver: I think it's a tough one, and that really depends. It's been very cool for us to see athletes that test a lot. What does it look like one day after a race versus one week versus two weeks? And really, athletes just change very quickly. I would say the factors that are definitely the most important are you want to bring that inflammation level back down. That would take at least a week, if not two. You certainly want those muscle damage markers to recover, which would also take at least a week, if not closer to 10 days. And, refueling is a really, really big one also. Making sure that your body has had ample time to really build up that 2,600 calorie deficit that you maybe just created for it.

I would say at least one to two weeks of very light training. Maybe the first week is not training, just sitting on the couch with some walking. And week two could be incorporating just some light things. My recommendation is for people to set two goal races a year, and not have more than two things that you are really, really pushing for. And that's just because that will allow your body to be able to not only recover from tough training blocks, but also for your body to adapt to the training stressors that you've put on it. Through most races, and training for races, the goal is really to improve your endurance, your physical fitness, and those just aren't things that we can really realize the benefits of training if we are constantly putting our body under those stresses. It needs time to really respond and adapt to them.

Analyzing and reassessing

After my January test, I included some next steps in my blog. Here they are along with a progress update:

  • Eating seafood four times a week. Achieved.

  • Eating nuts daily, as well as more frequent nut butters. Increased consumption of nut butters, eating nuts about three or four times a week.

  • Drinking more water daily. Didn’t measure; need to keep at it.

  • Taking the Ashwagandha twice daily after meals. Achieved.

  • Trying to sleep longer and meditate more regularly. Not achieved.

With my new set of data and recommendations from InsideTracker, here are the goals for the next several months:

  • Magnesium: Add a magnesium supplement.

  • Nuts: Hit daily target of consuming nuts or a nut butter.

  • Water: Increase water consumption, especially with warmer weather here.

  • Seeds: Increase seed consumption to four times weekly.

  • New proteins: Experiment more with tofu, try out teff and adzuki beans.

  • Rest: Sleep longer and meditate more regularly.

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