-
All Products
All Supplements
Xendurance
The Endurance-Boosting Supplement that Every Runner Needs
#1 Improve Workout or Race Time
Clinically proven to reduce lactic acid and improve running performance - Extreme Endurance is a must have for any runner.
Whether you are gearing up for your next marathon or want to set a new 5K PR, this is a must have product to put to the test.
#2 Increase VO2 Max
Increase your pace and be able to hold on. Extreme Endurance makes it feel like you have a third lung while preventing your muscles from tightening up.
#3 Trusted By World Class Runners
Contributing to personal records, American records, and World Records - Extreme Endurance has been used by runners for over a decade to help break barriers.
Donavan Brazier set the American Record in the 800m after being on Extreme Endurance for two months.
#4 Improve Recovery Time / Less Muscle Soreness
Feels like putting on a brand new pair of running shoes every day.
Look forward to putting in more miles when you don't feel yesterdays workout.
By reducing Creatine Kinase (CK) levels by 6x means your muscles recover better during workouts and help speed up recovery.#5 Clinically Proven + Tested By Informed Sport
Supported by 12 Clinical Studies and certified free of banned substances by Informed Sport. It feels like a performance enhancing drug, but isn't.
Goodbye Soreness
Hello Performance
GOODBYE SORENESS
HELLO PERFORMANCE
Increase Performance
Improve Power & Vo2 Max 10-25%
Recover Faster
6X Reduction of Creatine Kinase
Less Muscle Soreness
26% Reduction in Lactic Acid
Endorsed by:
Proven In
12 Clinical Studies
Recover Faster
Fights free radical damage & supports crucial cellular functions.
Stamina Increase
Push your limits to go the distance, fight fatigue and set PRs.
Increase Power
Increase power output by 10-25% with a similar heart rate.
Deeper Breaths
Increase VO2 Max & Aerobic Threshold. Perform better for longer.
Deeper Breaths
Increase VO2 Max & Aerobic Threshold. Perform better for longer.
Reduce Lactic Acid
Extreme Endurance reduces lactic build up after intense workouts.
Age Slower
Promotes anti-aging by reducing damaging oxidative stress.
As proven in:
Journal of Athletic Achievement
ENA Conference, Vienna Austria
ENA Conference, Vienna Austria
Journal of Athletic Achievement
Trusted by
WORLD CLASS RUNNERS
Take a Look Inside
Extreme Endurance is fully compliant and:
Informed Sport
CertifiedFirst US company to use trusted global testing method
Gluten Free Preservative Free
Safe for celiacs and no bad fillers.
Zero banned
ingredientsIt’s an all-natural, electrolyte mineral supplement.
Made in
the USAProudly made and owned in the USA.
TRY our XND INTRO OFFER TODAY
XND INTRO OFFER
60 Day Money Back Guarantee
60 Day Starter Pack
$183.85$119.90
SAVE $64
Experience the World’s #1 Supplement for Stamina, Performance & Recovery.
Try the 60 Day Pack and get:
FREE Omega+D3
FREE $25 Gift Card
2 x Packs of Extreme Endurance
order now
4.76/5
Money Back
Guarantee1.3K+
Reviews
TEST THE
ONE WEEK CHALLENGE
See proven results within 7 days
TEST THE
ONE WEEK CHALLENGE
See proven results in 7 days
Day 1
Record workout before taking Extreme Endurance
Day 2-7
Start taking Extreme Endurance and don't skip any days
Day 8
Retest workout from Day 1 and see your performance increase
Day 8+
Maintain daily dosage for compounding benefits
Tried & Tested by
OVER 350K CUSTOMERS
For Elite Athletes and Aspiring Athletes
+1000 5-STAR REVIEWS
Customer Reviews
Based on 1913 reviews87%(1666)5%(102)2%(44)1%(24)4%(77)CWant to run farther and quicker?!This stuff is AMAZING. The more I use it ( along with training ) the less fatigue I am feeling. Definitely a must for any type of runner / athlete.
![User picture]()
Thank you so much for your amazing review! We are thrilled to hear that Extreme Endurance is working well for you. Our team is committed to providing high-quality products to support athletes like you. Keep up the great work and happy training!
DI PR’d!!!I’ve now PRd both my 10k and half marathon while taking extreme endurance. It works!
![User picture]()
That's amazing news, congratulations on your PRs! We're so happy to hear that Extreme Endurance is helping you reach your goals. We hope that you continue to see great results with our product. 💪 Keep pushing to the extreme!
OWon m age group and took second place in every other age group that dayMy husband loves this stuff. At 52 he has been killing it in all his races this year. He loves to compete in Triathlons but then also break up that sport and compete in all three sports separately now and then. So this year he did our local turkey trot. Now we also happen to live above 7,000 ft here in Southern California. And the competition is always brutal. But he completed the 0K in 54:16. A new personal best. Like I said, he loves this stuff.
![User picture]()
Thank you for your review! We are thrilled to hear that Extreme Endurance has helped your husband achieve amazing results in his races. It's great to hear that he not only excels in triathlons, but also in individual sports. Congrats on his personal best in the turkey trot at such a high altitude! We are happy to be a part of his success. Keep up the amazing work!
EMuy Buen Producto!!!Lo he tomando tal como dice las instrucciones, y me he sentido muy bien, al día siguiente no me encuentro adolorida y he podido correr más rápido en mi entrenamiento para maratón. Lo seguiré utilizando.
![User picture]()
Thank you so much for your review! We are thrilled to hear that Extreme Endurance has helped you feel better and perform better in your marathon training. We strive to provide products that make a noticeable difference in performance. We hope to continue meeting your expectations. Keep pushing to the extreme!
RXtreme enduranceI have been taking this for close to a month, and this product is awesome. I definitely felt a difference in my runs. Great product!
![User picture]()
Thank you for sharing your experience with Extreme Endurance. We are thrilled to hear that you have noticed an improvement after taking our product for close to a month. It's always great to hear feedback from satisfied customers like yourself. Keep up the good work and happy running!
DVery Effective! I Never write these…Amazing product! I am currently training for OCR (for the first time in nearly 8 years and in my 40’s)…my VO2 max has increased from 37.6 to 40.3 and climbing after only 4 days of use! Recovery, power and overall conditioning are improving in ways I haven’t seen before using this supplement. I can not wait yo see where I go next!
![User picture]()
Thank you for sharing your success with Extreme Endurance! We're thrilled to hear that it is working so well for you! It's amazing to see such a significant increase in your VO2 max in just 4 days of use! We're excited to see where this supplement takes you next. Keep up the great work!
Supplement facts
NON-GMO / Gluten Free / Preservative Free.
Contains no Yeast, wheat, corn, milk, eggs, soy, artificial colors, sugar, starch or flavorings.
100% Guaranteed
Backed by the XND Promise
Scientific Efficacy
Proven by rigorous scientific research and tested by unbiased 3rd parties.
State-of-the-Art Manufacturing
We only partner with Good Manufacturing Practice (GMP) certified and/or equivalent facilities.
Accessibility for All
We strive to make our product line available to athletes of all abilities!
Certified Drug Free By Informed Sport
3rd party tested to guarantee free of banned substances
60-Day Money
Back Guarantee
FAQS
How quickly will I see results with Extreme Endurance?
Extreme Endurance will be in your system and working within 48-72 hours. We can confirm this from 12+ years of clinical testing.
Can I take Extreme Endurance with other supplements?
Extreme Endurance can be taken together with almost every other supplement but you do not need to take any product containing Beta Alanine when taking Extreme Endurance.
Please reach out to info@xendurance.com for specific inquiries.Do I need to take Extreme Endurance with food?
You do not need to take Extreme Endurance with food.
Is Extreme Endurance certified drug free?
Extreme Endurance was the very first US sports nutrition supplement certified drug free by LGC; Informed Sport.
LGC is a world-renowned sports doping control and research laboratory, with over 50 years of expertise in anti-doping in sport. LGC has published over 300 scientific papers on methods for the detection of trace levels of substances that are prohibited in sport and has over 450 man-years of research into doping control.
LGC has been testing supplements and ingredients on behalf of reputable manufacturers and suppliers for over 15 years. It has tested tens of thousands of samples during this time and has also carried out a number of research studies to explore the prevalence of contamination with prohibited substances in products and ingredients.
LGC's research into supplements and contamination also includes several administration studies to investigate the levels of prohibited substances that could cause an athlete to fail a doping test. These have been published in peer-reviewed scientific journals. As a doping control laboratory, LGC works directly with sports authorities, national anti-doping organizations, and national governing bodies worldwide.
Is Extreme Endurance certified drug free by the NCAA?
There are no NCAA approved supplement products. The NCAA does not approve supplements. Since 2007, Xendurance has had thousands of NCAA student-athletes take Xendurance products and rely on the Informed-Sport certification which is a global testing method for banned substances. To learn more please find the Informed-Sport link.
Can Extreme Endurance be taken with caffeine?
Over the years we have found that some people have a very acidic diet and their diet may interfere with the dissolution of the product in the small intestine. On the other hand, one of our athletes drinks 12 cups of coffee per day and lives on Extreme Endurance with great results! Everyone is different but the few that have had issues cleared up the dissolution problem by limiting acidic drinks, red meat, and coffee when taking Extreme Endurance.
We now encourage people to take their caffeine within an hour prior to or after taking their tablets just as a precaution.Do I need to cycle off Extreme Endurance?
You don’t cycle with Extreme Endurance. You take it consistently, like a multivitamin; for training, performance, heart-lung function, and for better body pH and alkalinity.
Can an athlete take Extreme Endurance if under the age of 18?
We encourage a parent to email info@xendurance.com and provide the sport and activity level of their child and their age, and weight. We can then provide better guidance for the parent as to the experience we have seen with athletes using the product under the age of 18. We do not recommend anyone under the age of 14 use Extreme Endurance.
When should you take Extreme Endurance? What time of day?
The most important thing to remember when taking Extreme Endurance is to take it consistently like you would a multivitamin. You can split the morning and evening dosage to the time of the day that works best for you. Ex; If you take it at 6 am and 5 pm, we encourage you to try to take it around 6 am and 5 pm everyday. You can take it with or without food.
What is a “Load Dose”?
The normal dose of Extreme Endurance is 6 tablets per day: 3 in the morning and 3 in the evening. For athletes that will be having a significant event or an “extreme” event such as an ultra-distance race, a state meet, or an event that is more intense than your normal events, we recommend what is called a “load dose”. A load dose is taken 7-10 days out from the event and you increase the dosage to 8 tablets per day: 4 in the morning and 4 in the evening and you take 8 tablets for one day after the event and then drop back down to the normal dose of 6 tablets per day. In 2008, our pro-triathletes started using a load dose and they informed us they had their best results bumping up their dosage, so this is why we tell competitors in every sport to use the load dose.
What sports will benefit from using Extreme Endurance?
Since 2008 we have heard from every type of athlete, in every type of sport with the exception of “curling”. We are still waiting for a curler to come forward. So if you are a curler we want to hear from you! Runners, Ultra-distance, Marathon, Triathletes, Crossfit, Cycling, Jiu Jitsu, Swimming, Tennis, Golf, Surfing, Football, Basketball, Baseball, Motorcross, Paddleboarding, Skiing, Boxing, Rugby, Rock Climbing, Wrestling, Hockey - just not curling yet....
RUn Faster. Train Harder. Recover Better.
SET A NEW PR
Stop making excuses. Recover faster and perform at your best.
Proudly owned, manufactured and shipped in the USA, since 1998.
Get in touch: info@xendurance.comCompany Policies
