The Endurance-Boosting Supplement that Every Crossfit Athlete Needs
#1 Improve Workout Time
Clinically proven to reduce lactic acid and improve workout performance - Extreme Endurance is a must have for any crossfit athlete or weekend warrior.
Whether you are just getting started with high intensity training or you want to keep setting PRs, this is a must have product to put to the test.
Put our Extreme Endurance to the test with a one week challenge backed by a 60-day guarantee.
#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.
Proven to increase oxygen uptake and maintain peak performance for longer periods.
#3 Improve Recovery Time / Less Muscle Soreness
By reducing Creatine Kinase (CK) levels by 6x means your muscles recover better during workouts and help speed up recovery.
One of the primary benefits of Extreme Endurance is its ability to reduce lactic acid by up to 26%. Lactic acid build-up during high-intensity workouts can lead to muscle fatigue and soreness.
By minimizing this build-up, you can experience decreased muscle burn during workouts, allowing you to push harder and recover faster post-workout.
#4 Increased Energy Levels
Maintain a higher aerobic threshold which lets you push harder in workouts before hitting a "wall"
An improved aerobic threshold allows athletes to sustain higher levels of intensity for longer durations without tiring, which can lead to better workout performance
#5 Clinically Proven + Tested By Informed Sport & Trusted by World Class Athletes
Supported by 12 Clinical Studies and certified free of banned substances by Informed Sport. It feels like a performance enhancing drug, but isn't.
As seen on
4.9/5.0 (1,000+ Reviews)
26% Reduction of Lactic Acid = Less Muscle Soreness
39% Reduction of Oxidative Stress = Improves Performance
6x Reduction of Creatine Kinase (CK) = Muscle Recovery
Increase in Aerobic Threshold = Better Vo2 Max
Benefits within 72 hours
Certified by Informed-Sport
PROVEN IN 12 CLINICAL STUDIES
JOIN 300,000 CUSTOMERS OVER 10+ YEARS
TRUSTED BY WORLD CLASS ATHLETES
4X CROSSFIT GAMES ATHLETE & FORMER NAVY SEAL
5X CROSSFIT GAMES ATHLETE
6X CROSSFIT GAMES ATHLETE
Any Crossfit athlete or weekend warrior like you works out to push the limits and reach new heights. We’ve developed a super-supplement to help power your along the way, allowing you to train longer and harder with less damage and strain.
Recover Faster, Live Better
Fights free radical damage & supports crucial cellular functions
Promotes anti-aging by reducing damaging oxidative stress
Increases aerobic threshold and VO2 max for a longer, healthier life
Starts working within 48–72 hours
100% Guaranteed & Backed by the Xendurance 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