Sparkling water and flat water are both great hydration options. Some sparkling water may provide small amounts of minerals (sodium, calcium, magnesium potassium). Some people find it easier to meet their fluid needs with sparkling water as they enjoy the flavors and carbonation. The carbonation and flavors may also promote a sense of satiation, which can be a helpful substitute to sugary drinks and/or snacks. The carbonation may help with some indigestion, such as helping someone release trapped gas by inducing burping. Hydration needs depend on your size, age, activity level, and factors such as medications that affect your fluid loss. A general guide for adults is about 9 cups fluids a day for women (1 cup=250mL), and 12 cups of fluids a day for men, but you may need more in the heat or if you're active.
I'm not a medical expert or nutritionist, so I can't speak to the technical hydration science you're asking about. But I can share something relevant from my nine years of sobriety that might actually be more valuable for your readers. When I was drinking, I was severely dehydrated--alcohol is a diuretic, and I'd lose massive amounts of fluid. My skin looked sunken, my eyes were perpetually puffy, and I'd wake up feeling like absolute rubbish. The morning after drinking, I'd skip water entirely and order greasy takeaway, making everything worse. In early recovery, sparkling water genuinely saved me. I mentioned in my story about mocktails how I struggled with not holding a wine glass--that psychological component of drinking is massive. Sparkling water in a nice glass gave me something sophisticated to hold at social events without the 0.05% alcohol content that alcohol-free beers contained, which was a dangerous trigger for my alcoholic brain. For anyone in recovery reading this, the carbonation makes a real difference psychologically. It feels like an event, not a punishment. I'd recommend brands like San Pellegrino or Perrier because the glass bottles and the ritual of opening them mimics what we miss. That mental game matters more than people realize when you're rebuilding your life sober.
My name is Jesse Feder, a personal trainer & Registered Dietitian and contributor to https://www.mycrohnsandcolitisteam.com/I saw your query and I thought you might find this useful. There are no real nutritional/hydration benefits of sparkling vs flat water. Both contribute equally to you daily hydration goal. Sparkling water may make you feel fuller more quickly and therefore potentially cause you to drink less fluid. All types of sparkling water are hydrating. However, those with added salt and/or sugar, may be less ideal for hydration. This can be especially true for those that are not sweating or very active, as in this case you do not need any added salts or sugars. Hydrations varies person to person and is based on several factors such as weight, height, age, activity levels, sweat levels, environment, and health conditions. In general men want to consume ~3.7L/day on average and 2.7L per day for women. You can also use 1mL per calorie consumed as a base estimate as well. Beyond hydration, sparkling water may increase feelings of satiety and also help with indigestion. If you need any more information, I'm happy to reply as soon as possible via jfeder12@gmail.com. Please let me know if you have any questions, if it's not too much trouble my preferred link would be to my website https://www.mycrohnsandcolitisteam.com/