Perform. Recover. Repeat. At InsideTracker, we know that training and optimized performance is more of a journey than a destination, and even then, it’s more of a cycle than a straight line. As we reach short-term goals, new, longer-term goals come into focus, and the journey begins again.
A key study shows that these training cycles have more to tell us than meets the eye: with calculated, purposeful, and timely blood testing, we can maximize an athlete's performance throughout their season to minimize the likelihood of overtraining and injury. To this end, InsideTracker sat down with running coach, Megan Roche, MD, to talk about a new research study related to training, and how she uses blood analysis with her clients.
Meet Megan Roche, MD, running coach and national champion
In addition to holding the prestigious title of 2016 USATF Trail Runner of the Year at the ultra and sub-ultra distances, Megan Roche is a four-time national champion, the North American Mountain Running Champion, and a six-time member of Team USA. Megan earned her MD from Stanford Medical School and is currently pursuing her PhD in epidemiology.
Along with her husband David, Megan owns and coaches at SWAP Running. Megan understands the power of blood analysis, and uses it as an important tool for her training programs. Therefore, when a novel study on blood testing throughout an athlete's training season was published, InsideTracker sat down with Megan to talk about the study's findings. Let's dive in.
Findings from a study on blood testing during an athlete's season
The Journal of Strength & Conditioning Research published a study that quantified an athlete's health, performance, and recovery. Scientists concluded that by testing certain blood biomarkers at multiple, specific points in the training season, an athlete can peak under the hood and understand how their bodies are responding to their training load.  The study identified six major biomarker groups that best quantify physical fitness. Here are the categories and why they're important to your training.
1. Nutrition and metabolic health
Athletes are more likely to be deficient in key blood biomarkers like vitamin D, iron, folate, vitamin b12, and magnesium. By monitoring these biomarkers, athletes can identify (or rule out) any dietary gaps that may hinder athletic performance.
Metabolic markers help us understand how our bodies metabolize carbohydrates, fats, and protein for energy. So, it can in part explain energy levels, fatigue, recovery, and soreness.
Megan likes to focus on vitamin D year-round, "because that's a biomarker that's so important for energy and for preventing injuries. I never want that to be low."
2. Hydration status
Nearly all of the body's processes require water. And training speeds many of these processes up. Therefore, an athlete’s hydration requirement is higher than the average bear's, and even mild dehydration can significantly hinder an athlete’s ability to perform at his or her peak. Check out this article for detailed hydration guidelines during exercise.
3. Muscle status
Healthy muscles display (a) strength, (b)
4. Endurance performance
Your endurance performance relies on your iron status. Iron is a key component of hemoglobin, responsible for carrying oxygen from your lungs to your muscles. And it’s the speed of this lung>hemoglobin>muscle conveyor belt that determines your ability to perform aerobic activities like swimming, biking, or running. The bottom line: if you have low iron, you might not get enough oxygen to your legs, and may slow your running pace.
Ferritin is also important to watch. As a type of protein that binds iron, ferritin is most associated with iron storage. In fact, most of the iron stored in the body is bound to ferritin, which makes it a good marker of your body’s iron capacity.
Megan is always looking at iron levels, "I want to make sure that ferritin never gets low. InsideTracker's full iron profile is very helpful for athletes in particular, because sometimes after a race, ferritin is sky-high because of inflammation. It's nice to be able to tease apart the specifics with ferritin, TIBC, TS, and the whole iron panel."
5. Injury status and risk
A group of blood biomarkers spike after an injury. By tracking their recovery back to optimal, athletes can understand how well their bodies are healing. If these biomarkers remain high for longer than expected, it may mean that an injury persists. Check out this article on post-marathon recovery techniques.
Muscle damage and inflammation are to be expected with any sort of training; after all, we need to cause slight damage to our muscles in order to make them adapt and grow stronger. But chronic inflammation, caused by overtraining or insufficient rest, can leave an athlete prone to illness, injury, and poor performance.
The study identified five major time points throughout the training season in which an athlete should measure their blood biomarkers. 
When to test your blood biomarkers during your training season
1. Take a blood test during your pre-preseason
The off-season is typically a time for your body to make a full recovery. Testing your blood biomarkers prior to preseason establishes your baseline levels, quantifying how your body feels and functions in a well-rested state.
For Megan, a test around this time of year is critical, "I can see how my body has responded to the off-season. For me, that's around January 1st because I take December easy, and make sure that my iron levels are optimized. I spend my off-season at altitude, so I also look at hematocrit."
It may not seem intuitive to get your blood tested when you're feeling good, but this is actually when it's most important. As Megan puts it, "Say you're feeling great for several weeks, and then all of a sudden you don't. Because you've established your baseline, you can see how your biomarkers have changed, and can take action to recover."
2. Take a follow-up blood test post-preseason
At this point in your training cycle, you’ve likely spent a few weeks prepping your body for the regular season. Blood testing at this point helps you to understand how equipped your body is for the training it’s about to endure—and its resilience against injury. Results at the end of preseason can inform your training intensity out of the gate.
Megan tests around this time to make sure that her body is keeping up, and that she's maintaining critical biomarkers like vitamin D, iron, magnesium, etc."
3 and 4. Take your next blood test before and after a performance test
Take a blood test before and after a performance test or a particularly difficult training week, (not to be mistaken with prior to a large competition). This helps you understand how your body responds to especially intense bouts of exercise. Here, you can make adjustments to your training and fueling using InsideTracker's evidence-based recommendations to prepare your body for race day.
Megan's approach here is extremely tactical, "I like to test about three weeks out from an event, and I use these results to dictate my taper periods. So, if I find that my cortisol is very high or that my testosterone is very low, I strategically choose a longer taper into the race. Three weeks gives me enough time to test, receive my results, and then plan my two-week taper based on those results."
5. Blood test post-event
That race, competition, etc. was the pinnacle of your season – you laid it all out on the line. So testing here helps you understand how your body responds to such intense exercise. And if the outcome wasn't what you had hoped, it can help to shed some light. All in all, testing after your main event will help you better prepare for the next.
Megan recommends leaving a window between your race and your test. "I've had athletes who test immediately post-race. But I know they're going to see very high numbers of CK and very low testosterone. So I'd rather have athletes test two weeks after a race. Theoretically, by then, things should start to stabilize, and they should look a little bit better [which likely wouldn't be the case immediately after racing]."
The importance of testing, and retesting
Blood testing is most beneficial when you test a comprehensive set of biomarkers. Testing blood biomarkers multiple times throughout the training season provides tremendous value to compare results.
Being both a running coach and an epidemiologist, Megan realizes the value of retesting, "I like to see a trend of biomarkers for overtraining. I think it's difficult to look at one value and make a prediction from it. Overtraining is a spectrum—inflammation or cortisol can be super high, or testosterone low. These values may be acute (a reflection of just very recent training) or chronic (over a period of time). Either way, I want to see multiple data points to make data-informed training decisions."
InsideTracker not only makes bloodwork simple and accessible, but it guides you towards answering the question, "What do I need to do to improve." After receiving your blood results, you can view your personalized recommendations and add them to your action plan.
As Megan puts it, "You can go to a doctor and have them tell you that your levels are normal. However, "normal" is very different than those of an elite athlete. InsideTracker factors in your age, gender, activity level, and more to plot your biomarkers into zones, and gives calculated recommendations to improve."
What can you expect from an InsideTracker blood test? Once your blood test data is processed, you’ll receive your results. Download the InsideTracker app to receive insights and recommendations personalized to you based on your unique blood results. Learn more about InsideTracker's blood plans like the Ultimate panel. When you purchase a bundle of InsideTracker tests, the price per test is reduced.
- 1. Lee, Elaine C., et al. "Biomarkers in Sports and Exercise: Tracking Health, Performance, and Recovery in Athletes." Journal of strength and conditioning research 31.10 (2017): 2920. https://pubmed.ncbi.nlm.nih.gov/28737585/