Recent studies describe the potential effect of cycling while on antihistamine and antibiotic medications.
As the weather changes around the World and the season turn, many riders seek to reap the fitness rewards of their virtual cycling gains by venturing outdoors. Spring is a time of rebirth, with blooming flowers and budding trees lining your route, but it also signals a reawakening of runny nose-causing pollen and other sneeze-causing stuff.
Cycling while on antihistamines is common in athletes experiencing allergies and related ailments.
The usage of antihistamine medication to relieve allergy symptoms is a common and accepted practice. The incidence of allergies and the use of antihistamines in athletes is double that of the average population. (1)
The tendency for cyclists to breathe through their mouths during periods of aerobic stress causes an increased exposure of deep lung tissue to allergens. In addition to the long periods of time spent outdoors during endurance training and multi-day events.
Histamine has been found to assist in regulating blood flow in muscles, especially following exercise-induced stress. The increase in blood flow is suggested to aid in the repair and growth of muscle fibers following training. Therefore, the blockage of histamine production may profoundly affect exercise and athletic performance.
A recent study published in the Journal Science Advances provides evidence of the possible correlation. To establish a potential link, researchers conducted two experiments.
Experiment One: Short-Term Effects of Cycling While on Antihistamines
The test subjects rode an exercise bike for 40 minutes without taking antihistamine medication, then repeated the protocol while ingesting antihistamines.
After medication administration, a substantially reduced post-exercise blood perfusion of the musculature resulted in diminished training adaptations and impaired muscle recovery.
Experiment Two: Long-Term Effects of Cycling While on Antihistamines
The researchers provided half the subject pool antihistamines before performing the protocol above. They all then engaged in a six-week cycling regimen, exercising three times per week, and repeated the pre-test protocol.
In the chronic training group that took antihistamines, marked reductions in training-induced effects on aerobic capacity were noted.
Maximal exercise performance (like VO2 max, peak power output, and time to exhaustion), was moderately affected. Still, aspects related to submaximal performance (like submaximal heart rate and exercise efficiency) were severely impaired.
The authors also suggested that antihistamine medication blunted the body’s insulin and inflammatory response.
Author's Note:
The above literature search is a cross-section of the available studies and is in no way meant to be exhaustive or representative of all research, for or against. Please consult with a health professional before starting or stopping any medication program.
Should Athletes Cycle While on Antihistamines?
Histamine in our body contributes to elevations in skeletal muscle blood flow following exercise, which raises the question that antihistamine medications may impair performance and recovery.
In addition to the recent research cited, several other studies suggest that blocking histamines during and following exercise increases muscle damage (as evidenced by increased levels of markers of muscle damage), increases inflammation, and contributes to the severity of delayed-onset muscle soreness.
There are also several studies examining the role of antihistamines on athletic performance that contradict the above findings or have proved inconclusive. (2)
In addition, the sample size of the above study was relatively small and the precise role of the body’s histamine production on the muscles may not be fully understood. For this reason, further study and examination of the interaction between antihistamine medication and athletic performance and recovery must be performed.
You should follow your health professional’s advice when making drug choices and cycling while on antihistamines. In this case, the negative training and performance effects of suffering allergy symptoms may counteract the harmful effect of their treatment. Keep in mind, however, that research does show a potential impact on performance.
How About Antibiotics?
Just as cycling while on antihistamines, taking antibiotics as prescribed by your healthcare provider is generally safe. However, there are a few things to keep in mind.
- The sulfa-based antibiotic class can cause increased sun sensitivity making athletes more susceptible to dehydration and heat-related illness. Consider this when hydrating before, during, and after your event.
- Some athletes experience diarrhea and stomach upset while on antibiotic medications due to bacterial changes in the gut. Fluid loss resulting from gastric upset combined with sun sensitivity can cause dizziness, muscle cramping, fatigue, and headaches. Probiotics may help.
- Tendon strain and rupture are side effects of the Fluoroquinolone class of antibiotics (common ones are Cipro, Levaquin, Avelox, Floxin, and Factive). Consult your healthcare provider before exercising.
- Recent studies in mice reveal no link between training adaptations or performance, but antibiotics may affect your motivation to exercise—food for thought.
Tips For When Your Cycling While on Antihistamines and Antibiotics
- Be sure to communicate with your coach about your illness, your medications, and how they affect you. Your performance team will be able to provide an objective assessment of your training load and your body’s response and adjust accordingly.
- Keep a journal or include observations in your training log tracking fatigue levels and hydration needs while on medications. It will give you a good picture of what to expect in the short term and future.
- If an event falls during the time you’re taking medication, have a support crew available to provide water, electrolytes, sun protection, and observation of your status.
- If you experience any of the symptoms noted above, stop immediately to assess the situation and notify your healthcare professional if they persist or worsen.
Conclusion—Cycling While on Antihistamines
If your doctor prescribed antihistamines or antibiotics, there must be a reason. You’re sick, have allergies, or have an infection. Whatever it is, you’re not at your best, and your body is trying to win the race for your health.
It’s safe to cycle while on antihistamines and antibiotics, and your performance might not suffer, but your body’s ability to fight the intruder might. If you’re feeling run down, a workout can make things worse. Add stomach upset, dehydration, and ligament soreness, and you have a recipe for suffering.
Consult with your healthcare provider before making medical decisions. Look to your common sense when making health and wellness choices. Rest may be just what the doctor ordered.
Do you have allergies that get in the way of your riding?
Have you found an alternative to traditional antihistamine medications that work for you? Your fellow virtual cyclists would like to know!
(1) “Ample use of physician-prescribed medications in Finnish … – PubMed.” https://pubmed.ncbi.nlm.nih.gov/16586342/. Accessed 20 Apr. 2021.
(2) “A single dose of histamine-receptor antagonists … – PubMed – NIH.” 1 Mar. 2017, https://pubmed.ncbi.nlm.nih.gov/27493198/. Accessed 20 Apr. 2021.
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Semi-retired as owner and director of his private Orthopedic Physical Therapy practice after over 20 years, Chris is blessed with the freedom to pursue his passion for virtual cycling and writing. On a continual quest to give back to his bike for all the rewarding experiences and relationships it has provided him, he created a non-profit. Chris is committed to helping others with his bike through its work and the pages of his site.
In the summer of 2022, he rode 3,900 miles from San Francisco to New York to support the charity he founded, TheDIRTDadFund. His “Gain Cave” resides on the North Fork of Long Island, where he lives with his beautiful wife and is proud of his two independent children.
You will read him promoting his passion on the pages of Cycling Weekly, Cycling News, road.cc, Zwift Insider, Endurance.biz, and Bicycling. Chris is co-host of The Virtual Velo Podcast, too!
Short story : Aller Bee Gone.
Too short to read! Where’s my friend Doug and what did you do with him?
LOL. Totally pinned down w three grandkids under 6yr here in Monroeville all week!