# How should you fuel for Ironman 70.3 South Africa?

Source: https://www.healthnews24.co.za/answers/ironman-south-africa-nutrition-plan/
Publisher: Healthnews24 (South Africa's supplement answer desk)
Updated: 2026-10-27

> For an Ironman 70.3 in South Africa, take most of your carbohydrate on the bike at 60 to 90 g an hour, with fluid to thirst and sodium if you sweat heavily, then 30 to 60 g an hour on the run. Eat a carbohydrate-rich breakfast two to three hours before and use caffeine late. Practise the whole plan in training.

Key facts:
- An Ironman 70.3 (1.9 km swim, 90 km bike, 21.1 km run) takes most finishers about four to eight and a half hours, so 60 to 90 g/h of carbohydrate on the bike is supported (Jeukendrup 2014).
- Aim for 30 to 60 g/h on the run, where the gut tolerates less.
- Fuelling 300 g of carbohydrate costs roughly R175 with 32Gi Race drink, R300 with Biogen Elite gels and R900 with Maurten Gel 100 (October 2026, our calculation).
- ISSN caffeine dose is 3 to 6 mg/kg; use a late top-up and test it in training.

## What does a 70.3 demand?

An Ironman 70.3 is a 1.9 km swim, a 90 km bike and a 21.1 km run. Most finishers take roughly four to eight and a half hours, which puts the event in the "over 2.5 hours" fuelling zone. South African race days add heat, humidity on the coast and often wind.

## What is the carbohydrate plan?

Jeukendrup's framework supports up to **90 g/h** beyond 2.5 hours with glucose and fructose, and 60 g/h for 2 to 3 hours. The gut copes best on the bike (seated, steady), so load there and ease off on the run.

| Leg | Typical time | Carbohydrate | Fluid |
|---|---|---|---|
| Swim | 30 to 50 min | none; eat before | none |
| Bike | 2.5 to 4 h | 60 to 90 g/h | drink to thirst, add sodium if salty |
| Run | 1.75 to 3 h | 30 to 60 g/h | sips at aid stations |

For a 5.5-hour finisher: about 210 g on the bike (75 g/h for 2.8 h) and 90 g on the run, roughly 300 g in total. Cost at October 2026 prices, using our cost per gram: 32Gi Race drink about R175, Biogen Elite Carb Gel about R300, SiS GO about R610, Maurten Gel 100 about R900. A common pattern is a carb drink in bottles on the bike and gels on the run. See [best carb drink for cycling](/answers/best-carb-drink-for-cycling-south-africa/).

## How much should you drink?

Sweat rates of 0.5 to 2 L/h are common, so run a sweat test on long bricks. Drink to thirst; overdrinking is the main cause of hyponatraemia, and slower athletes beyond four hours are at highest risk. Weigh in on rides: gaining weight signals too much fluid. See [what is hyponatraemia](/answers/what-is-hyponatraemia-in-endurance-events-south-africa/). Electrolyte sachets cost about R4.63 to R25 per serving (October 2026); read the sodium on the pack.

## When should you use caffeine?

ISSN supports 3 to 6 mg/kg. A common approach is a smaller pre-race dose, then a top-up late on the bike or early in the run. Maurten Gel 100 CAF 100 has 100 mg and costs R80 to R85. Test before race day. See [caffeine gels](/answers/caffeine-gels-for-endurance-do-they-work/).

## What about race morning?

Eat a familiar carbohydrate-rich breakfast two to three hours before the start, sip fluid, and carb load the day before ([how to carb load](/answers/carb-loading-for-a-marathon-how-to/)). Avoid new foods, high-fibre meals and large amounts of caffeine.

## Common mistakes

- Starting the bike too hard and running out of fuel on the run.
- Switching to gels you have never tried.
- Relying on salt tablets for cramps, which are not proven to prevent them.
- Skipping the swim-to-bike snack.

## Who needs advice?

Diabetes, kidney or heart disease, pregnancy, and medication affecting fluid or blood pressure need individual plans from a doctor or dietitian; Ironman 70.3 is an adult event. Treat heat illness (confusion, collapse) as an emergency.

## Products mentioned

| Product | Size | Price (source, date) | Servings | R per serving | Sweeteners |
|---|---|---|---|---|---|
| 32Gi Race High Intensity Sports Drink (900 g) | 900 g | R470 (Dis-Chem Living Fit, 2026-10) | 12 | R39.17 | None listed |
| Biogen Elite Carb Energy Gel, unflavoured (60 g) | 60 g sachet | R44.99 (Dis-Chem Living Fit, 2026-10) | 1 | R44.99 | None listed |
| Science in Sport (SiS) GO Isotonic Energy Gel (60 ml) | 60 ml sachet | R45–R49 (Sportsmans Warehouse via PriceCheck, 2026-10) | 1 | R44.90 | None listed |
| Maurten Gel 100 CAF 100 (40 g sachet) | 40 g sachet | R80–R85 (biket / goneoutdoor via PriceCheck, 2026-10) | 1 | R85.00 | None listed |
| Biogen Electrolyte (3 x 10 sachets, citrus) | 3 x 10 sachets | R139–R155 (Dis-Chem (electrolytes group), 2026-10) | 30 | R5.17 | Not published |

## Sources

- [Jeukendrup 2014, A step towards personalized sports nutrition: carbohydrate intake during exercise (Sports Med)](https://pmc.ncbi.nlm.nih.gov/articles/PMC4008807/)
- [Guest et al. 2021, ISSN position stand: caffeine and exercise performance (JISSN)](https://jissn.biomedcentral.com/articles/10.1186/s12970-020-00383-4)
- [Hew-Butler et al. 2015, Third International Exercise-Associated Hyponatremia Consensus Statement (BJSM 49:1432)](https://bjsm.bmj.com/content/49/22/1432)
- [Thomas, Erdman & Burke 2016, Position of the Academy of Nutrition and Dietetics, Dietitians of Canada and ACSM: Nutrition and Athletic Performance](https://pubmed.ncbi.nlm.nih.gov/26917108/)