The common guidance for men is roughly 3 to 3.7 litres of total daily fluid, food included. In practice, most men do well aiming for about 2.5 to 3 litres of drinking water, more if you train hard, sweat heavily, or live somewhere hot. A SIMPLE STARTING TARGET Take your body weight in kilograms and multiply by 30 to 35 millilitres. An 80 kg man lands between 2.4 and 2.8 litres. Add 500 to 750 ml for every hour of hard training. HOW TO CHECK WITHOUT MEASURING Urine colour is the field test: pale straw is fine, dark yellow means drink, completely clear all day means you are probably overdoing it. Persistent afternoon headaches and 3 p.m. fatigue are frequently mild dehydration wearing a costume. HOW TO ACTUALLY HIT IT Front-load. 500 ml on waking, before coffee. 500 ml with each of your main meals. One bottle beside you during training. That is most of the target before evening, which stops the 10 p.m. panic-litre that wrecks your sleep. WHAT DOES NOT COUNT AS FREE WATER Beer does not count. Neither does a fourth coffee. Coffee and tea are not the dehydrating villains they were once called, but if caffeine is your main fluid source you have a different problem. DO NOT OVERSHOOT More is not better. Drinking far beyond thirst dilutes sodium and does nothing useful. Consistency beats volume. MAKE IT AUTOMATIC The reason men miss hydration is not disagreement, it is memory. Set a cumulative daily goal, log each glass as you drink it, and let a reminder handle the middle of the day. The Barracks water tracker resets at local midnight and keeps the daily history, so you can see whether your bad training weeks and your low water weeks are the same weeks. They usually are.

How Much Water Should a Man Drink a Day