< Back to case studies

Andy Blow's scorecard

ÖTILLÖ Swimrun World Championship

Monday 5th September, 2022

Within recommended ranges

Just outside recommended ranges

Significantly outside recommended ranges

  • 81g

    Carb per hour
  • 444mg

    Sodium per hour
  • 338ml

    Fluid per hour
  • 1,315mg/L

    Relative sodium concentration
  • 6.90mg/kg

    Caffeine per bodyweight
  • How Andy hit those numbers

    2 x Plain Porridge Pots
    1 x White Bread Roll
    1 x Caramel Waffle (~20g carb)
    1 x Cup of Coffee
    1L x PH 1500 (Drink Mix)
    9 x PH Electrolyte Capsule
    1 x PF 30 Gel
    3 x PF 30 Caffeine Gel
    1 x PF 30 Chews
    4 x PF 90 Gel
    1.7L x Plain water
    3 x Energy gel (25g carb)
    2 x Energy gel with caffeine (25g carb, 100mg caffeine)
    300ml x Energy drink mix (32g carb)
    3 x Milk Chocolate Squares
    6 x Wine Gums

    How Andy's hydration and fueling went...

      • In what was Andy’s 4th trip to the iconic Swedish island race as part of the World Swim Run Championships, he and his race partner Lars Finanger achieved his fastest ever time of 8 hours 53 minutes and 43 seconds
      • Andy and his partner managed to execute a solid fueling and hydration strategy and finished strongly as they spent the last couple of hours picking off their competition


      • Andy has been prone to cramping and other hydration-related issues in the past. Considering his very high sweat sodium concentration of 1,800mg/L and a high sweat rate, he knew that staying on top of his sodium intake was going to be important
      • In his attempt to stay on top of his hydration, Andy took two PH 500ml/16oz Soft Flasks which he carried in his swimrun wetsuit pocket. To save weight, he added one PH 1500 (Drink Mix) packet to each flask, but didn’t add any water to them until he reached one of the early aid stations, when he began his hydration strategy
      • Once Andy had finished these bottles, he continued to take on sodium by taking nine Electrolyte Capsules, and in total he took ~3,945mg of sodium. Once his soft flasks were empty of electrolytes, he continued to fill them with plain water regularly throughout the race, totalling ~3L/96oz of fluid with a relative sodium concentration of ~1,315mg/L
      • Andy’s ability to add fluids to his bottles was restricted by the on course aid stations and the fact he was unable to drink whilst swimming, so he confessed to “not getting my hydration strategy quite right, but I don’t think it was too bad”
      • Interestingly, Andy’s fluid intake and relative sodium concentration were both lower than his 2019 attempt, which perhaps could in part have caused his hydration related issues such as muscle cramps in the latter stages of the race
      • Towards the latter parts of the race, Andy noticed a few twinges of cramp in his hamstrings and lower legs which progressively got worse as the race ensued. Around 10 minutes before the finish line he got such a strong cramp in his hamstring he had to stop running briefly, but was able to get across the finish line after this passed. This could be due to a slight electrolyte imbalance developing throughout the race, but could also be down to a lack of specificity of training his leg muscles for this type of event, given he only signed up three months prior!
      • In future, we’d recommend Andy preloads his sodium levels with a strong electrolyte drink the night before and again the morning of the race. This will ensure his blood plasma volume is optimally high, thus reducing the initial strain of exercise on his cardiovascular system, and slowing the decline in hydration expected with an event of this nature. Furthermore, perhaps taking a couple more Electrolyte Capsules along the way would bring his relative sodium concentration to be more in line with his sweat sodium concentration


    Quick Carb Calculator Recommendation


    carb 30 mins before


    carb per hour during
      • Andy knows (and has experienced) the ramifications of under-fueling long endurance races, so to make sure he didn’t experience any “bonking”, he carb-loaded in the days leading up to the race so his fuel stores were optimal come race day
      • On the morning of the race, Andy rose at 3:40am to get his pre-race meal in with plenty of time and get to the 06:00am start time without rushing. He topped up his muscle and liver glycogen levels with two pots of porridge, a bread roll and a caramel waffle (~20g carb)
      • Andy felt quite full after his rather large early-morning breakfast, so decided to skip his pre-race 30g gel. We usually recommend a last-minute carb hit around 15 minutes before the start to ensure there’s adequate glucose circulating in the blood when the gun goes off, thus sparing the stored energy for later in the race. However, due to the early start and his large breakfast, Andy made a judgement call and didn’t want to feel uncomfortably full heading into the race
      • The nature of swimrun ensures you’re largely self-sufficient in terms of carrying fuel which presents challenges. Having said that, Andy still managed to consume 692g of carb across the 24 run sections (totalling ~60k) and 23 swim sections (totalling ~9.1k). This gave him an average carb intake of ~78g per hour, which is a touch higher than the 75g/h recommendations from our Fuel and Hydration Planner
      • Furthermore, this intake of ~78g/h is an impressive 23g/h more than the last time he raced at the World Championships, where he averaged just 55g/h. Andy said “for certain, the increase in carbohydrate intake compared to last time was the most significant differentiators which lead to a better performance on the second half of the race”
      • Andy achieved this intake by carrying four PF 90 Gels, one PF 30 Gel, three PF 30 Caffeine Gels, and one PF 30 Chew (Mint and Lemon). He also picked up three more energy gels, two caffeine gels and three squares of chocolate at the on-course aid stations
      • He rated his perceived energy levels across the whole race 8-9 (out of ten), suggesting he did a solid job at consistently fueling himself, and said he “felt no real dips in energy”. Despite this, his level of GI comfort deteriorated throughout the race, as he rated this 8 out of 10 for the first five hours or so, but dropped to a 6 out of 10 towards the end, and he tapered his intake accordingly
      • Andy is a frequent caffeine user, and therefore chose to draw upon the performance boosting properties of caffeine during this race. In total he took ~500mg of caffeine, averaging ~6.9mg per kilo of bodyweight, which is slightly higher than the 3-6mg/kg that the scientific literature would recommend, but he saw no negative side effects and was therefore likely within his individual tolerances


      • Overall, Andy rated his race satisfaction 9 (out of 10) saying “it couldn’t have gone much better, but I’m a hard task master so don’t give 10s very easily”. With his partner Lars also fueling and hydrating adequately, they showed the importance of a rigorous strategy
      • Similarly to previous years, Andy has said this will be his final time doing this iconic race, but we’ll wait and see how that lasts as his memories of this race begin to fade and his competitive instincts take over!

    Key info

    Andy Blow

    Sweat sodium concentration
    Sweat sodium classification
    Very High
    * determined by a PH Advanced Sweat Test


    Overall Time

    Event information

    ÖTILLÖ Swimrun World Championship
    Sandhamn, Sweden
    5th September, 2022
    Swim Distance
    9.0km / 5.6mi
    Run Distance
    61.0km / 37.9mi
    Total Distance
    70.0km / 43.5mi

    Event conditions

    Weather Conditions
    No Rain
    Min Temp
    9°C / 48°F
    Max Temp
    15°C / 59°F
    Avg Temp
    12°C / 54°F

    Athlete feedback

    Event Satisfaction
    Hydration rating
    I didn’t nail this but it was not too bad
    Energy levels
    Solid energy nearly all day
    Toilet stops
    Yes many many times in the swims. Probably as much as 7 times. May be partly due to the cold water
    GI comfort
    It went in waves and deteriorated through the race. First 3-5 hours were an 8, ended on a 6 and tapered my intake accordingly
    Twinges but not full-on cramps

    Andy's Thoughts

     I couldn’t have gone much better!

    Andy's full stats

     Carbohydrate (g)Sodium (mg)Fluid (ml)Caffeine (mg)Relative sodium concentration (mg/L)
    Total intake7183,9453,0005001,315
    Per hour8144433856

    Data Confidence







    There is good confidence in the accuracy of the data reported. An athlete feels that the numbers closely reflect what they consumed despite a couple of estimations which may carry some degree of error. The majority of what was consumed is recorded to a high level of specificity (most volumes are known through the use of bottles brands quantities flavours). The numbers are very plausible and align with previous data recordings (if an athlete has collected data previously).

    Andy's recent case studies

    see all

    Related case studies

    Nail your next event with a FREE Fuel & Hydration Plan
    Get started