Want to run a marathon? An ultra marathon? Let's talk about it!

"Running" gets treated as one activity, but a thirty-minute jog and a hundred-mile ultra share a verb and almost nothing else. Different fuel systems, different failure points, different recovery math. If you've ever wondered why marathon training feels like its own discipline rather than just "running, but more," you're not wrong.

Let's talk distance running and what it does!

Thirty minutes in, not much is happening yet, but fuel sourcing is already on the move. Even holding the exact same pace, the body gradually shifts toward pulling more fuel from what's circulating in the bloodstream and less from what's stored locally inside the working muscle. That's the first quiet step toward the glycogen story that becomes a much bigger deal by hour three, nothing dramatic yet, just the tank starting to draw down.

One hour in, fluid losses have been adding up since the first few minutes of sweating, not starting now, and by this point they're substantial enough to matter if they haven't been replaced. Glycogen stores have been drawing down the entire time too, and depending on pace, they can already be meaningfully low well before the three-hour mark. That's exactly why marathon fueling strategies exist: gels and sports drinks during the race slow that depletion down rather than letting it run its faster, natural course.

Three hours in, marathon territory, is where things get interesting. This is roughly where the body's catabolic stress response shows up in the blood: in one study, cortisol rose 59% above baseline after a 3-hour run at marathon pace and stayed elevated through 1.5 hours of recovery before returning to normal. It's also where "hitting the wall" lives. More than 40% of marathon runners report hitting the wall during a typical race, with the likelihood peaking around mile 21. A large-scale analysis of over 4 million race records found 28% of male runners experienced a significant late-race slowdown consistent with hitting the wall, compared with 17% of female runners, a gap researchers attribute partly to men depleting glycogen faster and partly to women's somewhat better fat-utilization profile.

Six hours in is ultra-adjacent territory, and the cardiac story gets a little dramatic-sounding before it resolves itself. After a triathlon-length event, cardiac troponin and pro-BNP rose significantly immediately post-race but returned to normal within 12 to 24 hours, with no lasting impairment to left ventricular function detected on echocardiography. A separate marathon study using actual CT coronary calcium scoring found something reassuring: troponin elevations were extremely common after the race, but had no correlation with coronary artery calcification or plaque vulnerability. Your heart is working hard, not damaging itself. This is also where gut trouble tends to announce itself, since gastrointestinal symptoms during exercise affect 30 to 50% of athletes, driven largely by reduced blood flow to the gut as it gets redirected to working muscle. And your immune system takes a real, if temporary, hit: athletes who ran the LA Marathon were nearly six times more likely to report an upper respiratory infection in the week after the race than runners who didn't race that day, a phenomenon researchers call the "open window."

Into ultra territory, the same patterns just get louder. 2In the Badwater 216-kilometer race, a brutal multi-day event, NT-proBNP rose significantly higher in the runners who showed the largest troponin increases, suggesting cardiac strain genuinely does scale with how long you stay out there, even if it remains transient. Sodium balance becomes its own challenge: exercise-associated hyponatremia is primarily driven by over-consuming hypotonic fluids combined with the body's non-osmotic release of vasopressin, not by running out of salt.

There's also a slower-building question tied to that same gut-ischemia mechanism: what does repeated exposure to it, year after year, actually add up to? A preliminary study of 100 marathon and ultramarathon runners aged 35 to 50, none of whom had been previously screened, found nearly half had colon polyps and 15% had advanced adenomas, roughly triple the rate expected for that age group based on separate general-population data. This hasn't gone through peer review yet, came from a single center with no matched control group, and shows a correlation rather than a confirmed cause, so it's worth knowing about rather than worrying over. Still, it's a reasonable argument for not waving off persistent GI symptoms as just part of the sport.

Is endurance running worth it?

Short answer: for almost everyone reading this, yes. The cardiac and immune changes above sound alarming in isolation, but they're transient and don't represent lasting damage for people training for and running an occasional marathon or ultra.

The genuinely unresolved question lives somewhere else entirely. Long-term excessive endurance training, the kind performed by athletes who train at 10 to 20 times the standard activity guidelines for years on end, has been associated with pathologic structural remodeling of the heart and large arteries, even though moderate exercise remains unambiguously protective against cardiovascular disease and death. That's a real, active area of sports cardiology research, but it describes lifelong extreme-volume athletes, not someone training for their first (or fifth) marathon. Don't let a headline about elite ultra-veterans talk you out of your race.

How can we do longer distances safely as we age?

Think TIME over MILES!

Here's a counterintuitive one. In a study of runners preparing for South Africa's Comrades ultramarathon, lower training distance in the 12 weeks before the race was linked to a higher risk of injury, while sudden week-to-week spikes in training load had only a minimal effect on injury risk in this population. Training frequency mattered more than any single mileage number. In other words: the classic warning about "don't increase your mileage too fast" matters less here than simply putting in consistent time. Showing up regularly and building real time on your feet outperforms chasing a specific weekly total, especially heading into anything ultra-length.

However, looking at the most accomplished runners out there, they log enormous weekly mileage, but they aren't spending hours longer per session to get it done. What that buys them isn't simply "less load," it's a different kind of load, too. Pace determines how long your body sits inside the metabolic and hormonal stress this post just walked through: cortisol elevation, immune suppression, gut ischemia, all of it scales with duration, so finishing faster genuinely does mean less total time inside that stress window.

The mechanical side is more of a trade-off than a clean win, though, and worth knowing honestly rather than oversimplifying. As running speed increases, both cadence and ground reaction forces increase, meaning each footstrike hits harder at a faster pace, but because stride length lengthens more than cadence does as speed picks up, faster runners also take meaningfully fewer total steps to cover the same distance. Speed doesn't mean less impact, it means fewer, harder hits instead of more, gentler ones. Which one is actually easier on a given joint or tendon probably depends on the person and the structure in question, and it isn't something that research has settled cleanly either way.

How acupuncture can help!

Two of the specific problems that show up the longer you run are genuinely good targets for acupuncture! ... and no, it's not because I think acupuncture helps most things.

For the gut distress that tends to surface around hour six, acupuncture and electroacupuncture have fairly consistent effects on gastrointestinal motility, particularly at the points ST36 and PC6, with gastric motility being the most studied and best-supported of these effects. For the muscle soreness and damage that piles up over a long effort, a meta-analysis of acupuncture for exercise-induced soreness found it significantly reduced both perceived soreness and the muscle-damage marker creatine kinase while improving strength recovery. Neither of these replaces proper fueling, pacing, or hydration strategy, but acupuncture can be a great add-on to your recovery..

What about herbs?

Of the herbs studied for endurance support, Rhodiola rosea is recommended frequently and has the most directly relevant evidence. In a double-blind, placebo-controlled crossover trial, a single acute dose of Rhodiola rosea improved both time to exhaustion and VO2peak compared with placebo. The weird part? In that same study, four weeks of daily Rhodiola intake produced none of those benefits. A broader systematic review of ten studies on the topic found most reported a positive effect on athletic performance, along with reductions in muscle damage and pain after exercise, but the field as a whole is genuinely mixed rather than settled. The practical takeaway is specific enough to be useful: if Rhodiola has a real effect, the evidence points toward taking it acutely, closer to race day, rather than as a daily standing supplement.

If you're looking for alternatives to Rhodiola, the research on the digestive and inflammation side of endurance running points to a few options, often paired with beetroot or beet juice. Hawthorn stands out as the strongest of the bunch. Hawthorn extract shows a wide range of cardiovascular pharmacological effects, including antioxidant, anti-inflammatory, vasodilating, and endothelial-protective properties, with its strongest clinical evidence in chronic heart failure, and it's traditionally used in Chinese medicine specifically to support digestion alongside circulation. A 2021 study found that hawthorn tea reduced inflammation and oxidative stress in a rat model of colitis, real signal, though human research on hawthorn's effects in the gut specifically is still thin.

Panax ginseng, astragalus, and garlic each have genuine anti-inflammatory and gut-protective evidence behind them too. Ginseng and its active compounds show strong immunomodulatory and anti-inflammatory effects on intestinal inflammation specifically, while astragalus extract has been shown to reduce inflammatory markers and oxidative stress in intestinal cells. Garlic's case is more cardiovascular than digestive, but it's solid: in a randomized trial, aged garlic extract combined with CoQ10 improved vascular elasticity and endothelial function. None of this has been tested in runners specifically, but the mechanisms line up with the gut-ischemia story this post already covered.

One more thing worth knowing if you're combining any of this with training: timing matters, and probably not in the direction you'd guess. Reactive oxygen species generated during exercise act as a necessary signal for the body's adaptive response, and antioxidant supplementation can blunt training-induced improvements in mitochondrial biogenesis and other adaptations, an effect shown most consistently for vitamin C and E supplementation taken around high-intensity and resistance training. That's the well-tested part. Whether the same caution extends to anti-inflammatory herbs like the ones above is a reasonable inference from the same biology, not something that's been directly tested for hawthorn, ginseng, astragalus, or garlic specifically. Until it has, the more conservative approach is to keep strong anti-inflammatory supplementation away from the hours immediately around hard training sessions, and save it for general daily support or race-day use, when adaptation isn't the goal anyway.

Key takeaways

• Running for 30 minutes and running for 8 hours stress completely different systems: substrate use, cardiac biomarkers, fluid balance, and immune function all shift in distinct, fairly predictable stages as duration increases.

• "Hitting the wall" affects over 40% of marathoners and is a real glycogen-depletion phenomenon, not a willpower failure, with male runners somewhat more vulnerable to it than female.

• Cardiac biomarker elevations after marathon and ultra distances are common, transient, and not linked to coronary artery damage in the available data; the genuinely open question about endurance training and heart health applies to lifelong extreme-volume athletes, not occasional racers.

• A preliminary, not-yet-peer-reviewed study found elevated rates of colon polyps and advanced adenomas in long-distance runners, possibly tied to the same gut-ischemia mechanism behind exercise-induced GI distress; it's a real signal worth knowing about, not a settled finding, and a good reason not to dismiss persistent GI symptoms.

• For ultramarathon preparation specifically, consistent training frequency and time on feet predicted injury risk better than mileage spikes did.

• Acupuncture has specific, evidence-backed roles in supporting gut motility and muscle recovery during long-distance training, and Rhodiola rosea's best-supported use is as an acute, race-day dose rather than a daily supplement.

• Hawthorn, ginseng, astragalus, and garlic all show real anti-inflammatory and gut-protective effects in the research, hawthorn especially, but the timing matters: strong antioxidant supplementation taken too close to a hard training session can blunt the very adaptations you're training for.

Dr. Diane Stanley is a doctor of acupuncture and Chinese medicine. Blog content is for informational and educational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making changes to your health routine.

References

1. Romijn JA, Coyle EF, Sidossis LS, et al. Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration. American Journal of Physiology-Endocrinology and Metabolism. 1993;265(3):E380-E391. https://doi.org/10.1152/ajpendo.1993.265.3.e380

2. Heath GW, Macera CA, Nieman DC. Exercise and Upper Respiratory Tract Infections. Sports Medicine. 1992;14(6):353-365. https://doi.org/10.2165/00007256-199214060-00003

3. Rapoport BI. Metabolic Factors Limiting Performance in Marathon Runners. PLOS Computational Biology. 2010;6(10):e1000960. https://doi.org/10.1371/journal.pcbi.1000960

4. Smyth B. How recreational marathon runners hit the wall: A large-scale data analysis of late-race pacing collapse in the marathon. PLOS ONE. 2021;16(5):e0251513. https://doi.org/10.1371/journal.pone.0251513

5. Leetmaa T, Van Dam AM, Glintborg D, et al. Myocardial response to a triathlon in male athletes evaluated by Doppler tissue imaging and biochemical parameters. Scandinavian Journal of Medicine & Science in Sports. 2008;18(6):698-705. https://doi.org/10.1111/j.1600-0838.2007.00647.x

6. Paana T, Jaakkola S, Bamberg K, et al. Cardiac troponin elevations in marathon runners. Role of coronary atherosclerosis and skeletal muscle injury. The MaraCat Study. International Journal of Cardiology. 2019;295:25-28. https://doi.org/10.1016/j.ijcard.2019.08.019

7. de Oliveira EP, Burini RC, Jeukendrup A. Gastrointestinal Complaints During Exercise: Prevalence, Etiology, and Nutritional Recommendations. Sports Medicine. 2014;44(Suppl 1):79-85. https://doi.org/10.1007/s40279-014-0153-2

8. Giannitsis E, Roth HJ, Leithäuser RM, et al. New Highly Sensitivity Assay Used to Measure Cardiac Troponin T Concentration Changes During a Continuous 216-km Marathon. Clinical Chemistry. 2009;55(3):590-592. https://doi.org/10.1373/clinchem.2008.116566

9. Hew-Butler T, Loi V, Pani A, et al. Exercise-Associated Hyponatremia: 2017 Update. Frontiers in Medicine. 2017;4:21. https://doi.org/10.3389/fmed.2017.00021

10. Nieman DC. Immunonutrition support for athletes. Nutrition Reviews. 2008;66(6):310-320. https://doi.org/10.1111/j.1753-4887.2008.00038.x

11. Risk of pre-cancerous advanced adenomas of the colon in long distance runners. Journal of Clinical Oncology. 2025;43(16_suppl):3619. NCT05419531. https://ascopubs.org/doi/10.1200/JCO.2025.43.16_suppl.3619

12. Eijsvogels TMH, Thompson PD, Franklin BA. The heart of the ageing endurance athlete: the role of chronic coronary stress. European Heart Journal. 2021;42(24):2387-2398. https://doi.org/10.1093/eurheartj/ehab095

13. O'Keefe JH, Patil HR, Lavie CJ, et al. Potential Adverse Cardiovascular Effects From Excessive Endurance Exercise. Mayo Clinic Proceedings. 2012;87(6):587-595. https://doi.org/10.1016/j.mayocp.2012.04.005

14. Burgess T, Buchholtz K. Assessing the relationship between training load and injury in ultramarathon runners: a novel approach using Generalised Additive Models. South African Journal of Sports Medicine. 2025;37(1). https://doi.org/10.17159/2078-516x/2025/v37i1a20747

15. Leacox A, Fashingbauer L, Ferguson T, et al. The Effect of Running Speed on Cadence and Running Kinetics. International Journal of Sports Physical Therapy. 2025;20(7). https://doi.org/10.26603/001c.140544

16. Yin J, Chen JDZ. Gastrointestinal motility disorders and acupuncture. Autonomic Neuroscience. 2010;157(1-2):31-37. https://doi.org/10.1016/j.autneu.2010.03.007

17. Huang C, Wang Z, Xu X, et al. Does Acupuncture Benefit Delayed-Onset Muscle Soreness After Strenuous Exercise? A Systematic Review and Meta-Analysis. Frontiers in Physiology. 2020;11. https://doi.org/10.3389/fphys.2020.00666

18. De Bock K, Eijnde BO, Ramaekers M, Hespel P. Acute Rhodiola Rosea Intake Can Improve Endurance Exercise Performance. International Journal of Sport Nutrition and Exercise Metabolism. 2004;14(3):298-307. https://doi.org/10.1123/ijsnem.14.3.298

19. Lu Y, Deng B, Xu L, et al. Effects of Rhodiola Rosea Supplementation on Exercise and Sport: A Systematic Review. Frontiers in Nutrition. 2022;9:856287. https://doi.org/10.3389/fnut.2022.856287

20. Wang J, Xiong X, Feng B. Effect of Crataegus Usage in Cardiovascular Disease Prevention: An Evidence-Based Approach. Evidence-Based Complementary and Alternative Medicine. 2013;2013:1-16. https://doi.org/10.1155/2013/149363

21. de Paula do Nascimento R, da Fonseca Machado AP, Lima VS, et al. Chemoprevention with a tea from hawthorn (Crataegus oxyacantha) leaves and flowers attenuates colitis in rats by reducing inflammation and oxidative stress. Food Chemistry: X. 2021;12:100139. https://doi.org/10.1016/j.fochx.2021.100139

22. Pharmacological effects of ginseng and ginsenosides on intestinal inflammation and the immune system. Frontiers in Immunology. 2024;15:1353614. https://doi.org/10.3389/fimmu.2024.1353614

23. Adesso S, Russo R, Quaroni A, et al. Astragalus membranaceus Extract Attenuates Inflammation and Oxidative Stress in Intestinal Epithelial Cells via NF-κB Activation and Nrf2 Response. International Journal of Molecular Sciences. 2018;19(3):800. https://doi.org/10.3390/ijms19030800

24. Beneficial effects of aged garlic extract and coenzyme Q10 on vascular elasticity and endothelial function: The FAITH randomized clinical trial. Nutrition. 2013;29(1):219-225. https://doi.org/10.1016/j.nut.2012.03.016

25. Merry TL, Ristow M. Do antioxidant supplements interfere with skeletal muscle adaptation to exercise training? The Journal of Physiology. 2016;594(18):5135-5147. https://doi.org/10.1113/jp270654