Specifically for 70.3 racing? I sweat big time, both in fluid and salt content. I burned through three liters yesterday in a training ride of a little over 2.5 hours and probably could have consumed more. Two of the liter bottles had 1750 mg of sodium, one had 1500. Using precision hydration products. Wasn’t super hot, about 85 or so and some humidity and cloudy.
Is the general strategy for race day (70.3) to increase the salt content in the bottles and supplement with plain water from an aid station? How did you settle on how much salt was necessary? I’ll be racing in probably similar conditions as my training ride, likely in the 80s.
So I have done a few tests to see what my actual sweat rate is at different temperatures. I know at 30 celcius I sweat around 2L/hr and my race this weekend is around 20 so I am down to 1.5L/Hr.
To combat this I have a double bottle holder on the back, big profile design on the front and can store around 4L total in the bike. This is generally enough for me here. On the run, I wear a belt for a bottle and use that for 1L.
I generally haven’t needed aid station support on the bike, but sometimes walk through them on the run in the heat to grab a bunch.
Would suggest starting with testing and go from there because then you can see what your body needs.
I split up my nutrition/hydration/electrolytes so I can adjust depending on the course conditions. Just water in the bottles, a gel bottle BTS for calories, and salt caps in an M&M minis container in my trisuit pocket.
One thing to be aware of is that gels, drinks can have very different amounts of sodium.
PH includes practically no sodium in their gels: this is great to be able to control the three variables (carbs, sodium, water) separately but it means you have to purposely think about sodium. Maurten is another brand with almost no sodium content in their gels.
Other brands include sodium in their gels so if you rely on those then you don’t need to add much (or any) sodium.
If you’ll be using any of the products available at aid station then you’d need to keep this in mind also.
Have you completed a sweat test in representative conditions?
This has to be step 1 - being able to consume 3+ liters doesn’t mean that you need to.
Void your bladder
Weigh yourself
Ride at a representative intensity in appropriate conditions
Record what you consume
Weigh yourself prior to voiding your bladder again.
Repeat this across a range of conditions and times of year and you can get a good understanding of what you need and when.
Considering this is for a 70.3 distance, I would then look to limit you mass loses to 1-2% of starting body weight. It’s commonly thought that performance begins to decrease at 2% but there is some nuance to this.
Assuming your sweat rate is truly high, the biggest limitation is going to be your ability to carry enough fluids. If this is the case then I would begin experimenting with increased electrolytes immediately prior to the event (keep in mind that if you do this too soon, the effect is less pronounced).
If you want to try something that’s a bit more “Advanced” then you can look at supplementing with glycerol. It was previously banned as a plasma volume expander / PED masking agent, but as of this moment it’s currently allowed in and out of competition.
I often see advice about weighing yourself pre/post, which is fine but the biochemistry is a little more nuanced. The combustion reaction in your body runs as follows: CHO → CO2 + H2O (yes, pedants, I know it’s unbalanced but the point stands). You are losing water with every breath, so you need to be cautious attributing all water loss during a ride to sweat. The reason this matters is that exhaled H2O is free water, while sweat is an electrolyte mix. Obviously there are heavy and light sweaters (well played mathematics). But you may not actually be losing 2 L of sweat/hr, just because you’re 1kg lighter. But I agree with other posters that being able to titrate food, fluid, and electrolytes separately is a good idea.
Specifically for 70.3 racing? I sweat big time, both in fluid and salt content. I burned through three liters yesterday in a training ride of a little over 2.5 hours and probably could have consumed more. Two of the liter bottles had 1750 mg of sodium, one had 1500. Using precision hydration products. Wasn’t super hot, about 85 or so and some humidity and cloudy.
Is the general strategy for race day (70.3) to increase the salt content in the bottles and supplement with plain water from an aid station? How did you settle on how much salt was necessary? I’ll be racing in probably similar conditions as my training ride, likely in the 80s.
I aim for drinking 5-6 bottles in a 70.3 and ride 2:20-2:25ish. If it’s really hot I’ll have a couple extras prepped so I can chug one in T1 and another in T2.
I’ll start out of T2 with 4 bottles on the bike and jettison 2 or 3 at aid stations and pick up straight water over the course of ride.
Starting on bike/ person (down jersey):
1 bottle is just electrolytes
2 bottles is heavy concentration of tailwind for calories and salt
1 is plain water
My feeling is you aren’t drinking enough liquid given your sweat rate.
Thanks for all the replies. Lots of helpful information. Looks like I am going to be that guy that has a dual rear bottle carrier and three more on the bike.
I’ve weighed myself before and after activities somewhat regularly. It’s not uncommon for me to be down 8lbs or so after a hot long ride or a hot brick. That’s about 4% of my bodyweight.
Fall coming in the states so I likely won’t have to deal with the hot weather and huge fluid loss much longer, but my event is in Florida and it’ll certainly be warm.
On a hot day, I’ve come to peace with the fact is better to be that guy on the bike whose setup looks dumb (but has what he needs) than the guy with the sleek, pro looking setup that is walking the run
.
I live in Phoenix and have lost 20lbs on a training day. I use tailwind. 3 scoops per bottle and a relyte scoop per bottle on hot days 1/2 on cooler days. That’s 1700+ mg sodium per bottle.
I accept a certain loss in races and just do water gels and salt on a 1/2
Glycerol/Glycerin oil is really good for pre-race/pre-training hyperhydration. It was a thing in the 90’s but was put on banned substance list due to it’s ability to mask PED’s. It has been taken off the list but has been all but forgotten for endurance athletes.
It works really well when you expect to loose more than 2% of your bodyweight during exercise. Food grade Glycerol /Glycerin helps the body retains fluids. There are many good research articles on how use it and mix it according to your bodyweight. Tests have shown a notable increase in performance and decrease in fatigue in endurance athletes. Adding salt/electrolytes into the mixture helps even further. The mixture needs to be drank two hours before working out/racing. If you loose a lot of fluids/urination and are exercising more than 4 hours a diluted mixture can be ingested during activity.
Hardest thing was finding a good source for the oil. You don’t want it in powder form, it doesn’t mix well with water. Bodybuilding supplement companies sell it for increased vein “pump” but they usually contain extra things you don’t want and they are expensive. I found a source from an American company called Wildly. They make it (Vegetable Glycerin) themselves from Coconuts. Most oils online are made from palm oil in countries I wouldn’t trust for this product.
Overall it has worked really well for the intended purpose over the hot Texas summer and have had zero gastrointestinal issues. Will be doing 70.3 Waco in a few weeks and Roth in the summer.
For me, it’s a bunch of ice at every aid station down the sports bra. Can also go down the shorts for a really hot day. That + loads of gatorade and a little stash of salt if it’s going to be super hot.