Key takeaways

Allergy shots, a form of immunotherapy, can alleviate allergy symptoms by desensitizing the body to allergens, but may cause mild side effects that can be exacerbated by strenuous exercise.
Experts recommend avoiding exercise both one to two hours before and after receiving allergy shots to reduce the risk of increasing allergic reactions due to enhanced blood flow and allergen spread.
While regular moderate exercise can improve immune function and allergies, vigorous or strenuous activities should be avoided immediately before and after allergy shots to prevent potential reactions.
Light activities such as grocery shopping, stretching, or household chores are generally safe after allergy shots, but activities that increase heart rate and cause sweating should be postponed to minimize adverse effects.

When oral antihistamines and OTC nasal steroids don’t effectively treat allergy symptoms, people often seek relief from injections, also known as allergy shots. “Allergy shots are a form of immunosuppressive therapy that can help patients avoid triggers for a prolonged period of time,” says Sabrina Barata, MD, a primary care doctor at Mercy Personal Physicians.

Whatever your particular allergens are—often confirmed via formal allergy testing at an allergist’s office—allergy shots target your immune system’s response to those allergens, desensitizing your body enough to reduce the allergic reaction you typically have when you come into contact with them.

The problem? The desensitization process can cause some mild side effects, which may be worsened by any kind of strenuous or vigorous exercise. If you’re planning to get on an allergy shot regimen, here’s what you need to know about exercising before and after your appointments.

Can you exercise after you get allergy shots?

Even though 99% of expert-given health advice recommends exercising regularly, there are exceptions to that popular rule. Before and after receiving immunotherapy for allergies, commonly referred to as allergy shots, is one of those rare exceptions.

Dr. Barata says this is because allergy shots work by introducing small amounts of specific allergens to your body in order to trigger an immune response. That means there is a possibility of minor side effects, sort of like when you get a flu shot and feel achy, sore, or tired.

It also means that exercising can exacerbate this immune response, increasing your likelihood of symptoms.

“When you exercise, you increase blood flow and heart rate throughout your body,” says Kathleen Dass, MD, an allergist and immunologist in Michigan. “This causes the allergens to spread faster, which can increase your risk for an allergic reaction.”

So how long should you space out your workouts and your allergy shot appointments? “It’s generally recommended that you wait one to two hours before or after exercise,” says Dr. Dass, who adds that this recommendation applies to allergy shot appointments in both the buildup and the maintenance phases

Basically, regardless if it’s your first time getting an allergy shot or you’re an old pro, the recommendation is to avoid exercise immediately before and after your appointment.

What about allergy testing?

You should also avoid exercising right before and for three hours after allergy testing, according to the American Academy of Otolaryngic Allergy (AAOA). Again, it can increase your chances of having an allergic reaction, which can both skew your test results and cause severe reactions.

Can exercising boost or reduce your immune response to allergy shots?

There’s not much evidence either way that exercising before or after allergy shots has an effect on your body’s immune response. The risk with exercising too close to receiving your allergy shots is only about having an increased chance of reaction, not about increasing or decreasing immune function.

Dr. Dass notes that exercise in general has been shown to help improve allergies; it’s widely accepted that regular moderate exercise improves immune function, and some studies have suggested that this can have benefits on allergic rhinitis symptoms as well.

That said, other studies caution that there are benefits and drawbacks to engaging in physical activity if you have allergies and asthma, so make sure you always get your provider’s approval before performing vigorous or excessive exercise.

Are any workouts okay to do after allergy shots?

Generally, says Dr. Dass, the recommendation to avoid working out before and after allergy shots applies to all exercises. But she adds that strenuous and vigorous exercise has been reported more often as increasing your risk for a reaction—so while some normal physical activity as you go about your day is likely fine, anything that really gets your heart pumping should be avoided.

Types of activity that are usually okay

You don’t have to put yourself on bedrest before and after your shots; as long as you can do so without sweating or needing to catch your breath, it’s okay to move your body and perform light activities such as:

Going up and down stairs
Stretching
Vacuuming or cleaning the house
Walking back and forth to the subway for work
Gardening
Grocery shopping

Activities that should be avoided

Any exercise that helps you break a sweat is good for you…as long as it doesn’t happen right before or after your allergy shots. You should plan to avoid activities such as:

Running or jogging
HIIT exercises or other types of cardio
Lifting weights
Strenuous forms of yoga and Pilates
Dance classes like Zumba

Symptoms to watch out for

After you receive your shots, your provider will usually require you to wait 30 minutes before leaving the office so they can monitor you for adverse side effects. One symptom you probably won’t note, thankfully, is fatigue: “Although fatigue is a common symptom patients note with allergies,” Dr. Barata says, “it is not a common symptom after an allergy shot.”

Common allergy shot side effects include:

Redness or irritation at the injection site
Hives and itching
Tightness in the nose, throat, or chest

Rarely, patients may experience anaphylaxis after allergy shots.

The common symptoms often appear quickly, but Dr. Barata says they can occur up to two hours after receiving your shots. They’re also less likely to appear in people who are in the maintenance phase, or who have received allergy shots before. Still, if you experience any of these symptoms after you have left your provider’s office post-shot, call your provider ASAP, consider going to the nearest emergency room, or if necessary, call 911. If you’re prone to severe allergic reactions, your provider may also prescribe an epinephrine pen for you to have on hand, in case of emergency.

If you do find that your allergy shots make you uncomfortable (i.e., you feel itchy or have a runny nose), Dr. Barata says you can ask your provider if it would be beneficial to take an antihistamine prior to testing to avoid the possibility of allergic reactions. Consider having your allergy shots done in the morning and wait in the physician’s office for 15-30 minutes afterward.

Bottom line

If exercise is a part of your regular routine, that’s great! But you should take a break from any kind of strenuous or vigorous exercise immediately before and after receiving allergy shots to reduce your risk of allergic reaction. Basically, if your exercise regimen increases your heart rate and makes you sweat, skip it.