A cortisone injection delivers a potent anti-inflammatory medication, often combined with a local anesthetic, directly into or near a joint or tendon to manage pain and inflammation. This treatment is frequently used in the shoulder to address conditions like tendinitis, bursitis, or impingement syndrome. While the relief can be substantial and rapid, the body requires a careful period of rest and recovery to maximize the injection’s benefits and prevent complications. This guidance provides a typical, safe timeline for returning to shoulder exercise, emphasizing that this general advice does not replace the specific instructions provided by a physician.
Immediate Restrictions After the Shot
The first 24 to 48 hours following a cortisone injection are a mandatory period of absolute rest for the shoulder. This initial restriction allows the corticosteroid medication to settle into the targeted tissue and begin its anti-inflammatory action effectively. Patients must avoid heavy lifting, pushing, pulling, or any strenuous physical activities involving the injected shoulder. Routine activities, such as light walking, are generally permitted, but the goal is to significantly limit the use of the arm.
A temporary increase in pain, known as a “cortisone flare,” may occur within the first 48 hours after the procedure. This reaction is thought to be caused by the body’s response to the crystalline nature of the injected steroid solution. Applying a cold compress or ice pack can help manage this temporary discomfort, but heat should be avoided as it can increase blood flow and potentially exacerbate the initial inflammation. It is also important to refrain from submerging the shoulder in water, such as in hot tubs or swimming pools, for at least 24 hours to reduce the risk of infection at the injection site.
The Progressive Return to Exercise Timeline
The safe return to full exercise is a gradual, phased process that prioritizes protecting the healing tissue while restoring mobility and strength.
Days 1–2: Complete Rest
The initial phase requires almost complete rest, with the shoulder remaining still. Only gentle, passive movements are permitted if explicitly approved by the treating physician. This minimal movement helps prevent stiffness without stressing the injection site.
Days 3–7: Gentle Range-of-Motion
Focus on resuming light daily activity and introducing gentle, controlled range-of-motion exercises, such as pendulum swings or finger walks up a wall. It is crucial during this week to avoid all overhead movements, lifting anything heavier than a small book, and any activity that causes a sharp increase in pain. The initial pain reduction from the cortisone should be taking hold, making it easier to gauge the body’s true tolerance for movement.
Week 2: Low-Impact Activity
The beginning of the second week marks the time to introduce low-impact exercise that does not engage the shoulder. Activities like walking, stationary cycling, or using an elliptical machine are acceptable, provided the arms remain relaxed and the shoulder is not subjected to repetitive impact or resistance. Resistance training and sport-specific movements should continue to be avoided, as the injected area remains vulnerable to strain despite the reduction in pain.
After Two Weeks: Strength Training
The gradual return to strength training begins after a minimum of two weeks post-injection. At this point, the temporary weakness induced by the steroid should have subsided, and the long-term anti-inflammatory effects are more fully established. When restarting resistance exercises, begin at a significantly reduced intensity, typically 25% to 50% of the pre-injection weight or resistance level. A slow, controlled progression, with careful attention to pain signals, is necessary to safely rebuild strength without risking a setback or injury.
Understanding the Cortisone Mechanism for Recovery
The primary goal of a corticosteroid is to rapidly suppress the localized inflammatory response that causes pain and swelling in the joint or tendon. Cortisone acts by inhibiting the release of chemicals that drive inflammation, offering substantial pain relief that can be felt within a few days. This quick relief, however, can create a false sense of security, encouraging a person to push the shoulder before the underlying tissue has fully stabilized.
The mechanism of cortisone also involves a temporary, localized effect on connective tissues, which is the scientific reason for the required rest period. Glucocorticoids can interfere with the metabolic processes of tenocytes, the cells responsible for maintaining tendon structure. This can temporarily lead to a disorganization of collagen fibers and a reduction in the tensile strength of the tendon at the injection site.
Studies have shown that this biomechanical weakening effect can significantly reduce the load-bearing capacity of the tendon for up to three weeks following the injection. Applying excessive force or engaging in high-intensity exercise during this window of vulnerability dramatically increases the risk of serious injury, including tendon rupture. The waiting period is a protective measure, allowing the anti-inflammatory benefit to be realized while minimizing the risk associated with the temporary tissue weakness.
By adhering to the prescribed rest period, the shoulder joint benefits from the reduced inflammation, and the transient negative effect on the collagen structure has time to resolve. This coordinated approach ensures that the return to exercise is built upon a foundation of reduced pain and restored tissue integrity, rather than simply masked symptoms.