- It helps you improve your glide over the ground in sink and in a headwind.
- It helps you reach obvious climbs quicker.
- It improves your XC speed and therefore your distance.
- It might be needed to keep up with other pilots which will allow you to work with a gaggle rather than alone.
- Many gliders stiffen when you press some speed bar so actually feel nicer on the glide as they cut through minor turbulence better, rather than getting bounced around.
Of course using the bar has potential downsides such as the glider being more prone to collapse and it being more dramatic when it does go. Flying full speed is generally more stressful, especially in active air.
So... is there a balance to be struck for pilots not pushing at the front of a high level competition task? I think there is.
The most obvious first thing is to allow yourself enough terrain clearance. What comprises "enough" depends on a lot of individual factors but generally would be: enough height to recover a collapse. After that, a good starting point is to use 30% - 50% bar on every glide unless there is a good reason not to.. This setting gives you a healthy gain without the disadvantages stacking up too much. The rewards are less in downwind XC flying and greater if you are following mountain ridges. At the FlyFuther event in Slovenia, the pilots getting more from the days will be gliding significantly faster than trim whenever they feel it is safe to do so.
It takes practice and mental acclimatisation but if it becomes your new default, your flying can only benefit. You can build it into your on local soaring flights, so that you ready when the big day comes.
And remember - never apply brakes whist you are on the bar!