Half-Marathon Hydration: Drinks, Gels & Aid Stops

Plan drinks and fuel together

Think about the gel and the drink you’ll have with it. A gel can feel too strong with only a sip of water, while a sports drink and a gel together may give you more carbohydrate than you planned.

Write the sequence as one timeline. Note which stations provide water, which provide sports drink and where each fuel portion will be taken. Rehearse the same brands and approximate timing on long runs.

• Record prepared drink concentration, not just powder scoops.
• Check carbohydrate and sodium per serving.
• Keep an alternative if the stomach becomes unsettled.

Use a sweat test to set a starting range

A representative sweat test can narrow the starting range, but a result of 1.0 L/hour does not automatically create a 1.0 L/hour drinking target. The planner starts below measured loss and caps the range because full replacement may be impractical or promote overdrinking.

Try the test in different seasons. Use the result alongside how thirsty you felt, the temperature, your pace and how your stomach felt.

Plan the start and first station

The first station often arrives before much fluid is needed. Decide in advance whether it is a planned stop, an optional sip or one to pass. That gives you one less thing to decide when runners crowd around the station.

If you start with a sloshing stomach, feel bloated or keep needing the toilet, try drinking more gradually before your next race.

Adjusting when race day changes

If the forecast becomes hotter, revise pace, clothing, cooling and warm-up as well as drink opportunities. If it becomes cold and wet, thirst and sweat loss may be lower than the rehearsed warm-weather plan.

A delayed start also changes the timeline. Keep enough familiar fluid and food for the delay, but do not keep drinking continuously merely because you are waiting.

Work out when you’ll reach each station

Write each station’s distance and the time you expect to reach it. At 5:00 per kilometre, a 4 km gap takes about 20 minutes. At 7:30 per kilometre it takes about 30 minutes. That changes how much you’ll drink in an hour if you take a cup at every station.

Mark stations as planned, optional or pass. A planned station supports a fuel or refill decision, an optional station responds to conditions, and a pass prevents crowd behaviour from silently increasing intake. Recheck the schedule if your realistic finish time changes.

• Use the current organiser map and drink list.
• Estimate the amount actually swallowed after spillage.
• Identify where course congestion may make drinking difficult.

Try the plan at your expected race pace

Drinking and eating can feel different when you’re running harder. Try the same drink, gels and caffeine you plan to use during a faster section of a training run and see how your stomach feels.

Use at least one appropriate rehearsal to test the exact container, product concentration and timing at a controlled section of expected race effort. The purpose is not to run the whole race in training; it is to reveal handling, swallowing and gastrointestinal problems while changes are still possible.

Know what’s available at the finish

The finish area may involve queues, a walk to baggage and only unfamiliar drinks. Know what is supplied and keep a familiar recovery option available when practical. Begin gradually and combine fluid with normal food rather than rapidly chasing the largest estimated deficit.

Write down what you drank, leftover volume, weather, finish time, stomach comfort and any carefully measured body-mass change. If recovery time before the next demanding session is long, ordinary meals and drinking over several hours may be more appropriate than an aggressive replacement formula.