Truant19 wrote:
Hi All, I have spent the last few weeks looking at what fuel I am going to be using this season for my 70.3 and IM this summer so I can start training with it. After doing some research it all seems really expensive (especially in Canada), and I know in the past I end up not fueling properly in training because I am always worried about 'wasting it'. I want to start making my own, but I am always second guessing myself and worried about making something with a molarity that is to high that will bomb my guts. Can you guys just double check that this thought process is correct?
Proportions:
- 1:1 GLU-FRU ratio (can also do 1:0.8 GLU/FRU to make it a bit cheaper)
- Roughly 500-1500mg sodium per liter. Closer to 1500mg if sweating a lot. Closer to 500-1000mg if barely sweating. (tsp of sodium citrate = 1000mg of sodium)
- 600ml - 1L of fluids per hour
- No more than 120g of carbs per 1L of fluid
- High concentrations are ok as long as you are drinking enough fluids
- Are other electrolytes besides sodium required?
Ingredients:
500ml Home Made Mix: - 500ml water
- 30g Maltodextrin
- 30g Fructose
- 0.5tsp of sodium citrate
- 1 drop of mio
Thanks for the double check!Looks great!
On fluid: Some folks can handle more than 1L per hour. Sometimes by a lot. Just don't let sodium concentration dip towards the bottom end of that 500-1500mg range while simultaneously pushing 1.5L of fluid per hour. Hyponatremia is not performance enhancing. :)
On concentration: What you've said is a good safe bet. Higher concentrations, like 130g/L or 140g/L, and sometimes 150-180g/L can be handled in a well-hydrated state and when exercise intensity is that of a 70.3 or 140.6. But, that doesn't mean it's optimal. 120g/L is a great place to land on the bike, especially if you're able to intake ≥1 L/hr anyway!
It's when folks aren't sweating much that sometimes it's optimal to push for a slightly higher concentration. No need to onboard so much fluid when you're not losing it, but still very much optimal to target ideal carb intakes of 90-140g/hr, if it's a long event and you're well-practiced at doing so. Yes gut training matters, but practice fueling matters more (ie. don't be inconsistent, and practice listening to gut).
On potassium (and chloride, for fun): I'm not absolutely certain that potassium isn't necessary. But I'm getting very close. If it is helpful or useful, it's only helpful in tiny amounts, and is only very
very slightly useful. Read: I can't tease out performance benefits or any mechanism by which it would be directly performance enhancing.
Same statement could be made for chloride.
What I
am sure of, is that the amount of potassium and the amount of chloride, in most products, is more harmful than useful. It's inclusion in beverages, in any amount seems at least as likely to be harmful as useful, in most cases. Just more for your gut to deal with.
On maltodextrin + fructose, vs. sucrose, ratios, sweetness, & osmolarity: Reasons why some folks might want to use maltodextrin to drive a slightly higher glucose intake than 1:1:
- Reduced sweetness
- Reduced osmolarity
But, if targeting a 1:1 ratio of glucose:fructose, sugar actually has very slightly lower osmolarity than average maltodextrin products which average about 10 glucose molecules per chain, unless stated otherwise. And, about the same sweetness.
If ever targeting a ratio of glucose:fructose that is anything greater than 1:1 (ie. 1:0.9, 1:0.8, 2:1, etc), then maltodextrin is the optimal choice for providing that added glucose.
On flavor intensity and sweetness: Generally, unless you're my wife, most folks prefer lower flavor intensity and sweetness during exercise. She likes her drink to kick her in the teeth. I'm quite the opposite.
If you were making
my beverage, I'd say: add the tiniest drop of mio possible. For me, just enough flavor to mask the flavor inherent to the sugars is optimal.
Salt &/or sodium citrate can always be used to combat any sweetness overload, and probably should be. I find this to be one of the best reasons to include a very small amount of table salt (NaCl) in the beverage, along with the sodium citrate.
Keep in mind that flavor preferences tend to change towards less sweet, less intense flavors, and greater salt flavor the longer the training session or race goes.
The "kitchen taste test" will sometimes be misleading.
PS. You're going to love the app my team and I are building, but you may not even need it by the time we get it released. ;) It takes all this into account + your feedback, settings, and qualitative inputs about sweat rates, and makes it all brainless for every activity you do, every day. Shoot, maybe you can help beta test it when we release in public beta. Just a thought. Private beta starts next week. Public in a couple months. FWIW, neither potassium, nor chloride, are prescribed in the present app version and I have no formal plans for their inclusion.
Dr. Alex Harrison | Founder & CEO | Sport Physiology & Performance PhD
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