RickH wrote:Whilst caffeine (not just in coffee) is a mild diuretic its effects, at least on most people, do not mean you will pass more fluid than you take in. If you have a 1/2 pint (10 fl oz for any readers of an American disposition) mug of medium strength coffee or tea you probably get the hydration benefit of at least 9 fl oz of the liquid. Plus any rest, emotional & social benefits that you may also get.
The performance benefits of making sure you don't get mildly dehydrated also should not be over-exaggerated for a leisure cyclist either. The 3% dehydration giving 10% loss of power may well be true & relevant for athletes performing at or near maximum power. For the rest of us it probably mean that that steep hill that we would normally get up at 60% of capacity needs us to run at nearer 70% if we're running a bit dry. It may make us huff & puff a bit more or, on harder terrain, ride a little slower, but it isn't generally going to have a huge impact.
In the United Staes, a PINT is 16 oz, so 1/2 pint is 8 floz.
32 oz is a quart. The usual Mickey D cola, enough for an 1800 kCal, 80 - 100 km bike ride.
Warning. Be careful when you drop a High5 Zero tablet in full sugar cola. It throths up like a fire extinguisher.