Cortisone shots offer quick pain relief for joint and tendon problems. How we manage you afterwards depends on factors such as what was injected and how active you were beforehand. So do you need to rest after a cortisone injection, and when can you return to weight training and running?

What happens right after a cortisone injection?

Once you’ve had a cortisone shot, offload the injected area for the rest of the day. A knee or foot injection means reducing your step count; a shoulder injection means avoiding lifting or reaching with that arm. Key aftercare for the first day:

  • Keep the area clean. Leave the bandage on until the end of the day, then wash the area.
  • Don’t submerge it. Showering is fine, but avoid hot tubs and swimming pools for 24 hours.
  • Manage any flare. Apply ice for 10-15 minutes every 2-3 hours and take ibuprofen 400mg three times daily until a flare settles.
  • Avoid heavy activity (walking, running, cycling) after hip, knee, or foot injections.

(Cortisone has other potential side effects beyond the flare – we cover those in full on Are Cortisone Injections Bad for You?)

What to do for a cortisone flare

The commonest reason for pain after a shot is a cortisone flare. It usually starts after about 6 hours and lasts up to 5 days (one study found an average of around 4 days). It happens because cortisone can form tiny crystals that briefly irritate the soft tissue.

If you get a flare, rest from activities, including the gym and running, until it settles, ice the area for 10 minutes every 3-4 hours, and take ibuprofen 400mg three times a day.

How long do you need to rest after a cortisone injection?

As a general rule, rest the injected area for two days, then gradually increase activity. If a flare is still present after two days, keep resting until it settles.

After that, the return to activity depends on what was injected. Joint injections need less time; tendon injections need longer – usually 1-2 weeks, and longer still for weight-bearing tendons such as the Achilles, patellar, gluteus medius, and peroneal tendons.

Returning to the gym after a cortisone injection

men weight training after a cortisone injection

Return to the gym generally around 3-4 days after the shot, starting with body parts away from the injected area, then gradually loading the injected structure from about day 7, protecting it to day 10.

Example: modified gym programme after a shoulder tendon injection

  • Days 1-2: Rest the shoulder. Ice every 4 hours and take ibuprofen until any flare settles.
  • Day 3: Return to the gym for lower-body exercises and lower-limb aerobic work.
  • Day 7: Reintroduce lighter back- and pulling-focused exercises; avoid pushing (shoulders, chest).
  • Day 10: Reintroduce lighter shoulder and chest work at 50% of your previous load, and restart physiotherapy.
  • After day 10: Gradually increase weight and intensity under a physiotherapist’s guidance.

Returning to running after a cortisone injection

For upper-limb injections, you can repeat after 2 days or once the flare settles. For lower-limb injections, rest from running for about seven days – generally 7 days for joint injections and 10 days for tendon injections.

Example: modified running programme after a hip joint injection for hip arthritis

  • Days 1-2: Rest the hip. Ice every 4 hours and take ibuprofen until any flare settles. Cut your step count by 50%.
  • Day 3: Upper-body weights and swimming without kicking.
  • Day 7: Cross-training – cycling and lower-body weights.
  • Day 10: Restart physiotherapy.
  • Days 14-21: Return to graded running under a physiotherapist’s guidance.

Frequently asked questions about resting after a cortisone injection

Will activity straight after a cortisone injection ruin it?

Not usually. Activity soon after a shot can increase the risk and intensity of a flare, but if you haven’t developed a flare, a bit of walking is unlikely to undo the injection. The main reason to rest is to avoid provoking a flare and, for tendon injections, to protect the temporarily weakened tendon.

Can I walk after a cortisone injection in my knee?

Avoid heavy walking straight afterwards, and reduce your step count for a few days – especially if a flare develops. Using public transport, a car, or a taxi for 3-4 days after a knee injection helps.

Can I drive home after a cortisone injection?

Best not to drive yourself immediately. Insurers often require you to be able to perform an emergency stop, and cortisone can briefly cause dizziness or affect your vision. Arrange a lift, taxi, or public transport, and resume driving the next day if any flare is mild.

How long after a cortisone shot can I drink alcohol?

Alcohol increases blood flow and bleeding, so avoid heavy drinking for 24 hours after a shot.

Can I take painkillers after a cortisone injection?

Yes – paracetamol and ibuprofen are both fine, and ibuprofen also helps with a flare.

Why shouldn’t I use heat after a cortisone injection?

Heat increases blood flow, which can worsen swelling and pain. Use ice (10-15 minutes every 3-4 hours), not heat packs, in the first few days.

Final word from Sport Doctor London about resting after a cortisone injection

As a rule, rest the injected area for at least two days. Depending on what was injected and why, returning to the gym or running takes from 7 to 14 days. An experienced doctor will tailor this to your injection and your goals.

To discuss a cortisone injection with Dr Masci in London, contact the team here or call +44 (0) 203 488 0350.

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