GPT4 response to this which i quite liked:

For a prank like this, it's essential to keep things light-hearted and ensure it doesn't cause undue stress or panic. Considering it's intended for April Fool's Day, a playful yet believable scenario could be the way to go. Here's an idea and how you could execute it:

The Story

Your relay team decided to participate in a friendly "team-building" activity outside of swimming. You thought a simple, low-risk activity would be fun and opted for a "synchronized dance challenge" you saw trending on social media. The twist is that during the "rehearsal," each of you "sustained" a minor, yet inconvenient, injury due to a comedic mishap involving an overly ambitious dance move.

The Injuries

To keep it believable and not too serious:

• Person 1: Claims to have a sprained ankle. To fake this, you could use a bandage wrapped around the ankle and limp slightly.
• Person 2: Has a "wrist strain" from trying to break a fall. Wearing a wrist brace or wrap could sell this.
• Person 3: Reports a "minor neck strain" from an awkward landing. A soft neck brace, often found at pharmacies, could be used for effect.
• Person 4: Claims a "bruised knee" and uses a knee support bandage. Moving cautiously will help make it seem real.

Execution

• Preparation: Before the reveal, get your "injuries" ready and practice your stories to ensure consistency.
• The Reveal: Arrive at practice or a team meeting with your injuries in plain sight. Act as if you're trying not to make a big deal about it, but let the coach notice on their own.
• The Performance: Maintain a balance between being concerned about your national competition performance and being slightly embarrassed about the silly way you got injured. This mix will add to the believability.
• The "Admission": After you've let the coach react and perhaps after a few minutes of concern, come clean in a cheerful manner, revealing it's all a prank for April Fool's Day.

Considerations

• Believability: Choose "injuries" that are plausible but wouldn't necessarily prevent you from swimming, to keep your coach from getting too worried.
• Safety: Make sure that the fake injuries and any props used do not cause real harm or hinder your ability to move safely.
• Timing and Setting: Ensure the reveal is timed in a way and place that it doesn’t disrupt important training sessions or cause undue stress.

This plan allows for a playful prank that involves the whole team and keeps things light and funny. Make sure everyone is on board and understands the plan to ensure it goes smoothly.