Ant Gritton's scorecard
Manchester Marathon
Sunday 16th April, 2023
Within recommended ranges
Just outside recommended ranges
Significantly outside recommended ranges
94g
Carb per hour
480mg
Sodium per hour
160ml
Fluid per hour
3,000mg/L
Relative sodium concentration
4.17mg/kg
Caffeine per bodyweight
How Ant hit those numbers
1L x PH 1500 (Tablet)
1 x PF 30 Chew
2 x Almond Butter & Salted Caramel Porridge Pot
1 x Black Coffee
1 x PF 30 Caffeine Gel
1 x PF 30 Energy Chews
400ml x PH 1500 (Two Packets)
2 x PF 30 Caffeine Gel
1 x PF 90 Energy Gel
How Ant's hydration and fueling went...
- Ant had mixed feelings from his second standalone marathon, running a stunning new PB, but an unplanned bathroom break meant he missed his sub 2:30 target by just 11 seconds
- Having thought the race was over at the halfway point when his stomach discomfort arose, he restarted his fuel and hydration plan soon after, and closed strongly
Hydration
- With temperatures expected to be low on race day (average ~10℃ / 50℉), Ant still ensured he started optimally hydrated by preloading his sodium levels beforehand
- Whilst out for dinner the night before the race, Ant and Minty made sure they had a tube of PH 1500 Tablets with them, which they added to their glasses of water, increasing their blood plasma volume and help reduce cardiovascular strain
- During the race, Ant set off with a Soft Flask with two PH 1500 Packets in, which he planned to drink before halfway, where he was also going to switch his fluid intake to plain water from aid station to effectively dilute the concentration
- Unfortunately the stomach issues he faced around halfway delayed the consumption of his soft flask, and he only finished it at ~32k (20 miles). This meant his total fluid intake was far below his plan at just ~400ml (13oz), with an average of just ~160ml (6oz) per hour
- Furthermore, Ant’s sweat sodium concentration is 1,351mg per litre which means he’s a salty sweater. As he didn’t manage to pick up any water on course, the relative sodium concentration of the two PH 1500 Packets was ~3,000mg/L, or very salty
- As the race was only two and a half hours, thankfully, Ant didn’t experience any negative side effects from this, but found he was incredibly thirsty afterwards. In future, Ant could look to reduce the concentration of his Soft Flask when temperatures are low, or ensure he gets the required fluid intake to reduce the total concentration on-the-fly
Fueling
Quick Carb Calculator Recommendation
30g
carb 30 mins before
60-90g
carb per hour during
- Ant topped up his energy stores by carb-loading for a couple of days beforehand, and you can see exactly how he hit the recommended 8-12g of carb per kg of bodyweight here
- Then, on race morning, he had a high-carb breakfast and a PF 30 Chew to top off these glycogen stores. Whilst he stood in the start pen with ~20 minutes to go, he took another PF 30 Chew and ~10 minutes later he took a PF 30 Caffeine Gel
- This will have primed his blood glucose levels optimally, and circulated some caffeine into his bloodstream so he could reap the ergogenic benefits associated with it later in the race. In addition to this, Ant took another two Caffeine Gels during the race to keep his levels topped up, and ensure his intake was within the 3-6mg/kg body weight recommended range
- In terms of carbohydrate intake, in addition to the two Caffeine Gels, Ant also had a PF 90 Gel, which he sipped on throughout the run. In total, this gave him an average intake of ~94g per hour, including his pre-race Gel and Chew
- Despite his toilet stop, Ant rated his GI comfort a 7 (out of 10), and importantly his energy levels were also really good (10 out of 10). His glucose trace (check it out here) was somewhat surprising, with a gradual increase up until the point he stopped for the loo. After this brief stop, it then gradually declined for the rest of the race, even though his perception of energy remained high, and he picked off runners in the latter stages
- Ant felt his stomach issues were likely caused by nerves and anxiety in the early stages, which are known causes of higher-than-normal glucose levels (read more about this here). Thus, once he stopped, believing his “race was effectively over”, this adrenal response was suppressed, and his glucose levels fell to more “normal” levels
Conclusions
- Ant learned several valuable lessons both in the lead-up, and during this marathon. Firstly, carb-loading was tougher than he thought, and to hit the recommended target intake he actually had to focus his attention on reaching the recommended carb-loading recommendations, which are significantly higher than his usual day-to-day diet
- Secondly, he plans to race another marathon later in 2023, and will look to increase his fluid intake and/or reduce his sodium consumption to more closely match the saltiness of his sweat. This could also help reduce the likelihood of any future GI issues
Key info
Ant Gritton
Male
72kg
Sweat sodium concentration
1351mg/L
Sweat sodium classification
Very High
* determined by a PH Advanced Sweat Test
Event information
Sport
Running
Discipline
Marathon
Event
Manchester Marathon
Location
Manchester , England
Date
16th April, 2023
Website
Total Distance
42.2km / 26.2mi
Total Elevation
140m / 459ft
Race conditions
Weather Conditions
Cold
Precipitation
Rain
Min Temp
8°C / 46°F
Max Temp
11°C / 52°F
Avg Temp
10°C / 50°F
Humidity
89%
Athlete feedback
Race Satisfaction
9/10
Hydration rating
9/10
I possibly over-hydrated pre-race, which could have caused the toilet stop, but during I think I was fine
Energy levels
10/10
I didn't have any lows and was regularly picking off runners in the latter stages
Toilet stops
Yes
GI comfort
7/10
I had to use the toilet at 14 miles, but afterwards I was right as rain!
Cramping
No cramping
Ant's full stats
| Carbohydrate (g) | Sodium (mg) | Fluid (ml) | Caffeine (mg) | Relative sodium concentration (mg/L) | |
|---|---|---|---|---|---|
| Overall | |||||
| Total intake | 234 | 1,200 | 400 | 300 | 3,000 |
| Per hour | 94 | 480 | 160 | 120 | |
Data Confidence
1
2
3
4
5
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).