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Paul Newsome's scorecard

Rottnest 19.7km Swim

Saturday 25th February, 2023

Within recommended ranges

Just outside recommended ranges

Significantly outside recommended ranges

  • 43g

    Carb per hour
  • 254mg

    Sodium per hour
  • 356ml

    Fluid per hour
  • 714mg/L

    Relative sodium concentration
  • 0mg

    Total caffeine
  • How Paul hit those numbers

    500ml x PH 1500 (Tablet)
    1 x Bowl of Porridge
    1 x Tbsp of Honey
    1 x Effervescent vitamin tablet
    1 x Double shot espresso
    1.25L x PF 60 Energy Drink Mix
    1.5 x PF 90 Energy Gel
    500ml x Plain water

    How Paul's hydration and fueling went...

      • Paul is an extremely experienced swimming coach and marathon swimmer, who has previously crossed the English Channel and won the 48km Manhattan Island Marathon Swim in 2013
      • Paul took on the Rottnest Swim for the 12th time in 2023 and, having tried to break 5 hours for the 19.7km distance since he was 31, he was incredibly happy to cross the finish line in 4:55:46 at 44 years old. For the first time ever, he even felt like he could have gone harder, which he partly attributed to his pacing and partly to nailing his fueling better than during any previous attempt


      • We know from experience that getting fluids on board during long swims can be difficult due to the practicalities of stopping to drink, so it's important to make sure you start hydrated. Paul sensibly made sure he was optimally hydrated by preloading with a PH 1500 tablet in 500ml (16oz) of water before the race started
      • Paul drank a total of ~1.75L (62oz) of fluid while swimming, which averaged out to ~356ml (13oz) per hour. The one thing Paul would have changed about this race was drinking a little bit more. However, he was held back by some bladder discomfort, and being unable to pee in his very tight swim skin suit
      • Because Paul weighed himself before and after the race, we’re able to work out his hourly sweat rate. With a loss on the scales of 1.8kg in 5 hours, and an approximate weight of the drinks he consumed totalling 1.75kg, his total losses across the race were roughly 3.55L (125oz)
      • This works out at an hourly sweat rate of ~720ml (25oz) and does suggest that a higher fluid intake on the day would have been appropriate. For context, if he hadn’t drunk anything, he would have lost ~3.5kg (123oz) in sweat, this is equivalent to ~4.5% of his body weight
      • This is important to know, as the scientific literature generally suggests that physical performance may start to decline in individuals after around 2-4% dehydration, and so could have caused some issues. Although, having done this successfully for a long time, it’s likely that Paul’s tolerance to moderate dehydration is more robust than others
      • Paul sensibly added electrolytes to his drinks in the form of PF 60 Drink Mix. This resulted in him taking on ~714mg of sodium per litre (32oz) of fluid that he drank. As Paul has previously had a Sweat Test he knows that he loses 819mg/L (mg/32oz), and so can be confident that on this occasion he replaced a good proportion of his losses
      • Having ensured that he mitigated against the onset of muscle cramping due to electrolyte related causes, Paul was very pleased to report no cramps whatsoever throughout the race. This is especially pleasing as it’s normally something he struggles with in his quadriceps


    Quick Carb Calculator Recommendation


    carb 30 mins before


    carb per hour during
      • Having caught up with the Sports Science team, and his old swimrun World Championships partner Andy at PF&H, Paul planned to focus on fueling with more carb per hour than he ever had previously, which ended up being ~43g per hour
      • While from a scientific point of view you would have to double this carb intake to reach the top end of general recommendations for optimal performance at an event of this length and intensity, this was still a significant increase for Paul and provided him with more available energy than he’s had for his previous 11 outings at this race
      • In this situation, it’s often not sensible for an athlete to try to immediately increase their intake to 90g per hour and higher, because it can lead to stomach discomfort. To comfortably transition into taking more carb per hour a period of gut training can help massively
      • During the race Paul also had to contend with the impracticality of having to tread water and not touch his accompanying paddler’s boat while fueling, which naturally makes getting anything on board very tricky
      • With a strategy of stopping every 30 minutes, Paul alternated between taking ~⅓ of a PF 90 Gel with ~100-150ml (4-5oz) of water and ~250ml (9oz) of PF 60 Drink Mix. This strategy resulted in him taking ~43g of carb per hour and ensured he rated his energy levels on the day as a 9 and his gastrointestinal comfort as a 10 (out of 10)
      • Paul also had some jelly sweets and Coca Cola available in his boat throughout the swim, but never felt like he wanted them.
      • In future events of this length, Paul may look to reap the benefits associated with caffeine. Weighing in at ~77kg he would need to take 230-460mg to optimise his intake. An easy tweak to his race strategy if he were to do this is to swap out the PF 90 Gels for PF 30 Caffeine Gels, although he’d have to consider the practicality of the smaller packages when in the water


      • In a race field containing several Olympians, Paul was incredibly satisfied with his new personal best time and the achievement of finishing in under 5 hours. He said he ‘felt very well supported by his fuel & hydration strategy’, which gave him plenty of energy for the race and confidence going into the next one
      • Going forwards, Paul may look to increase his fluid intake slightly in order to avoid accumulating as much dehydration related to body weight loss, as well as position himself in a way where he will be able to pee comfortably if needed

    Key info

    Paul Newsome

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


    Overall Time
    Bodyweight change

    Event information

    Rottnest 19.7km Swim
    Perth, Australia
    25th February, 2023
    Total Distance
    19.7km / 12.2mi

    Event conditions

    Weather Conditions
    No Rain
    Min Temp
    17°C / 63°F
    Max Temp
    33°C / 91°F
    Avg Temp
    25°C / 77°F

    Athlete feedback

    Event Satisfaction
    Hydration rating
    I felt I could have taken on more fluid, although the practicality of swimming made this hard to achieve
    Energy levels
    Just the usual fatigue in my shoulders, I definitely didn't bonk which I think is part fueling and part pacing strategy
    Toilet stops
    I really needed to go from around the halfway mark but my swim skin suit was too tight!
    GI comfort
    No cramping

    Paul's Thoughts

     I'm really happy to have achieved my quickest time here at 44 years of age, having tried to go sub 5 hours since I was 31

    Paul's full stats

     Carbohydrate (g)Sodium (mg)Fluid (ml)Caffeine (mg)Relative sodium concentration (mg/L)
    Total intake2101,2501,7500714
    Per hour432543560

    Data Confidence







    There is some confidence in the quantities and brands of products consumed but the data may lack specifics (e.g. volumes, specific flavours). A high number of estimations have been made and the room for error is moderate-high. There may also be the possibility that some intake has been grossly over- or under-estimated.

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