• After a strong 5th place finish at the 2022 Dragon’s Back race in North Wales, Sam was looking to secure another top-10 finish when taking on the gruelling 2023 Arc of Attrition in the South West of England
• Sam worked with the PF&H Sports Science team in the weeks building up to the race to refine his fuel and hydration strategy, with the aim of breaking the 24-hour mark for the 100-mile event

Hydration

• Sam drank ~450ml (14oz) of PH 1500 electrolytes with his breakfast on the morning of the Arc to ensure he was going into the race properly hydrated. Science shows that preloading with a strong sodium-based electrolyte drink ~90 minutes before endurance exercise can boost blood plasma volume, which will have helped Sam’s ability to regulate his temperature and reduced the strain on his cardiovascular system during the first half of the race
• Overall, Sam was able to drink an average of ~313ml (10oz) fluid per hour, with a relative sodium concentration of ~1,139 milligrams of sodium per litre (mg/32oz)
• We know from Sam’s Sweat Test that he loses 819mg of sodium per litre of sweat (mg/32oz), so his intake of ~1,139m/L was probably more than was required given the temperate conditions. Sam may have overdone his sodium intake slightly, which might well explain the “puffiness” he experienced
• This said, Sam was happy to share that he experienced absolutely no cramping, which has previously been an issue for him when he’s underdone his sodium intake during events like this
• Interestingly, when comparing his body weight pre- and post-race, Sam actually gained 3kg (~6.6lbs). This may partially have been due to a prolonged period of maintaining a relative sodium concentration which was too high for his individual losses and so resulted in some excess fluid retention
• Sam mentioned that he craved Coca Cola from around mile 21. Alternatively known as the ‘Red Ambulance’ in endurance circles, we often observe athletes turning to cola during the latter stages of races as it can provide fluid, carbohydrate and some caffeine all at once
• Interestingly, he also made sure to include some protein in his fluid intake, which isn’t something we’d say is necessary for performance during a ‘single effort event’ like this whereby he won’t be using it for energy, however it would almost certainly have had a benefit on muscle restoration, via protein synthesis in his post event recovery
• During extremely long events, especially when they take place throughout the night, it’s extremely common to see athletes exceed the general recommendations of 3-6mg/kg of caffeine. On this occasion, Sam far exceeded this, consuming 20mg/kg
• Sam has a high tolerance for caffeine and experienced no adverse effects during the race itself, although he reported excessive post race sweating. High caffeine intakes combined with muscle damage have been linked to this occurrence
• In future races, Sam is going to optimise the timing of his caffeine intake, especially overnight when he’ll be fighting his natural sleep cycle, to exploit the 4-5 hour ‘half-life’, and benefit from the increased perceived energy associated with it

Fueling

Conclusions

• Sam was mostly happy with how he executed his fuel and hydration strategy en route to a 9th place finish at the Arc of Attrition
• He rated his overall race satisfaction as a 7/10 and he’s focusing on a couple of aspects ahead of his next ‘A-race’
• Sam took on more sodium than he had in previous races and he reported that he was happy to avoid the cramping issues he experienced in previous ultras. He will look to reduce the relative sodium concentration of his intake, by either reducing his sodium consumption or increasing his fluid intake, to see if this helps avoid the post-race weight gain and “puffiness” he experienced
• Despite eating a wide range of foods and fueling products, Sam rated his GI comfort as a solid 8 (out of 10). He’s going to look at finding a bit more structure with the fueling products he uses going forwards