The first few swings feel stiff, rushed or wild. Maybe the ball goes everywhere and you've already decided it's a bad day. Two things can cause this: a space you haven't checked, and a body that hasn't moved yet. Check the space and the gear first, then warm the body.
Check the space before the body
Do this first, with no ball on the mat.
One launch monitor maker, Garmin, lists adequate ceiling height and a clear backswing and follow-through as musts1. A retailer's setup guide says much the same thing in plainer words: take a few swings with different clubs in the intended space2. Do that slowly, and do it with the longest club you'll use. A longer club swings a bigger arc.
Then look at the people. Nobody should stand in the hitting area, or close beside it, while a swing is happening. That goes for kids and pets too. Ball rebound is real, so cover any hard surface near the hitting area the way your maker's guide says, and never aim into a bare wall or window.
Check the gear
Layout matters because the monitor reads your shot from a set position. For that Garmin model, the tee spot must be at least 8 ft (2.4 m) from the net when playing indoors1. The monitor goes on the ground between 6 and 8 ft (1.8 and 2.4 m) behind the tee1.
Your monitor may ask for something else. Read its manual and follow it for your own model.
Lining it up is easy. The same manual says you can lay a club on the ground between the alignment line and the tee spot to confirm they match1. If your numbers look odd all session, a nudged monitor is a cheap thing to rule out.
Warm the body
Think of a warm-up as a slow climb, not a switch. One description of warming up is a gradual increase in intensity in physical activity3. The same page says a warm-up should be specific to the activity3.
For golf indoors, that could look like this:
- Walk around the room, or swing your arms with no club.
- Turn your trunk gently left and right.
- Hold a club across your chest and rotate.
- Make slow swings with a short club, then a little faster.
Dynamic stretching means moving a body part through its range of motion3. That suits a warm-up better than long holds. The risks and benefits of mixing stretching into a warm-up are still disputed3, so keep it light. If anything hurts, stop. This site can't give medical advice, so ask a professional if you're unsure.
Ease into real shots
Start with a short iron. Hit a few half-speed shots, watching only whether the contact feels clean. Move to a mid-iron, then the longer clubs you plan to use. Leave the driver for later in the session, or skip it if today's job doesn't need it.
Don't read the numbers yet. Warm-up shots aren't data. Once you're loose, begin your first drill, such as a gapping session or some wedge work.
If the first swings are still bad
Slow down before you change anything. A rushed tempo is more common than a broken swing. Take a couple more practice swings with no ball, then hit one shot at easy effort. If the monitor is still odd, go back to the gear check.
Cited material
- Approach R10 Owner's Manual - Preparing for a Shot, Garmin
- How much space do you really need for your golf simulator, SimSpace Golf
- Warming up, Wikipedia