• The Precision Fuel & Hydration team first worked with French ultrarunner Pierre Meslet in 2021 when he attended a Sweat Testing workshop in London prior to competing in the Marathon Des Sables, a seven day multi-stage desert race in which he finished 9th. Since then, Pierre has been targeting faster, shorter distances with the Manchester Marathon being a target race
• Pierre’s aim for Manchester was to run below two-and-a-half hours but unfortunately suffered a tear in his calf just four weeks out from race day. This meant his final weeks of preparation were spent focusing less on high-quality preparatory sessions and more on whether or not he would be able to sustain a good pace for the duration of the marathon
• Despite the less than optimal race build-up, Pierre had a great day out in Manchester, setting a new marathon personal best of 02:35:25 and finishing 24th in his age-group (M35-39)
• Pierre felt that the disruption caused by managing injury during the few weeks before the race meant that he didn’t plan his fueling and hydration strategy for this race as well as he should have. But he still consumed an impressive amount of carbohydrate whilst suffering no GI issues, and took enough fluid and sodium to see him through the race without any major detriment

Hydration

• Pierre felt his hydration strategy left plenty of room for improvement. He chose to run with a 500ml/16oz soft flask which he finished around the half-marathon mark and then picked up one small bottle of plain water to refill it. Pierre estimated that in total he drank ~750ml/24oz over the course of the race, averaging ~290ml/10oz per hour
• Whilst this is a relatively low fluid intake (especially for Pierre who we’ve seen consume in excess of 1L/32oz per hour when racing in the heat at the MdS), it’s important to note that the conditions in Manchester were cool on the day (~9ºC/48ºF). Therefore, Pierre’s sweat losses would be expected to be lower and as a result his fluid intake should fall in line with these lower losses
• That being said, Pierre did feel like he required a bit more fluid during the race, estimating a further ~300-500ml (10-16oz) would have been optimal. Within 20-minutes of finishing the marathon, Pierre had drunk 500ml/16oz of a recovery drink mix, after which he felt much better; which would suggest that taking on some more fluid was necessary
• Similar to his fluid intake, Pierre felt as though he underdid his sodium intake towards the end of the race, commenting that he “didn’t carry enough sodium and should have carried some electrolyte capsules”
• Pierre preloaded before the race with PH 1500 as per recommendations and carried a sodium-rich drink mix with him during the first half of the marathon, which is a lot more than most athletes would do. In total, he consumed ~945mg of sodium (~366mg/h), which when we account for the fluid he drank, equated to a relative sodium concentration (a measure of sodium to fluid ratio) of ~1,290mg/L
• When we account for Pierre’s sweat sodium concentration (921mg/L), the relative sodium concentration of his intake was very good. Where Pierre may have improved his strategy was by drinking a greater absolute volume of fluid (and increasing his sodium intake to keep the relative sodium concentration the same), particularly towards the end of the race
• Pierre did experience some twinges of cramp from ~35km but managed to push through until the finish. Rather than this being directly associated with his sodium intake, Pierre suspects that this was a result of a lack of specific conditioning in the final weeks due to his injury
• Pierre’s recovery was slower and poorer than normal, rating it only 3 (out of 10), which he speculated may also be linked to his injury and lack of conditioning

Fueling

Conclusions

• Despite a less than optimal race build-up as he attempted to manage his calf tear, Pierre had a good race at the Manchester Marathon and clocked a new personal best. With his focus being on whether he could rehab his calf to a point where he would race, Pierre felt he didn’t prepare his fueling and hydration strategy for the marathon as well as he should have, falling short on fluid specifically, and felt that his lack of specific conditioning in the weeks prior affected his performance
• Overall though, Pierre had a great run given the circumstances, hitting very high carbohydrate numbers (>100g/h), with no gut issues or drops in energy levels, which bodes well for future marathons when the run-up to the race has hopefully been slightly smoother