Long runs on warm days - How much weight do you loose?

marathon2022

Hydration - only messing, not opening that can of worms(yet)

I started the Pfitzinger and Douglas 18/70 plan this week and as per the book, the first thing recommended is to read the book.

On hydration the (page 33) it advises weighing yourself before and after a long run to gauge how much you should drink to re hydrate. 1.5 x weight in water lost.

I went for a 16 mile medium long run at Heart rate reserve of 66-78% which is a HR of between 135 to 150 for me. Stayed around 142 for the run(7.45/mile average)

Weight before 80.1kg

Weight after 77.85

Using the recommendation I would take over 3 litre to rehydrate by the next day.

Is anyone else interested in throwing up maybe the odd weight before and after some long runs in the summer? And if you have a bespoke hydration method, what is it? Does the pee color test suffice of is it more rigorous?

If not now worries, I know its a bit personal and I'm just curious so no biggy

witnessmenow

I lost just less than 2kg on a 8k run last week.

I didn't have an exact before weight but was 90.1kg after which is basically 2kg less than expected, and returned to normal later in the week when I weighed again

marathon2022

https://www.boards.ie/discussion/comment/120736393#Comment_120736393

Thanks, I drank the prescribed 3 liters of water yesterday and was back to normal this morning. I hope the rehydration regime has a positive effect on recovery.

skyblue46

I'll join in on this over the next few weeks...an interesting topic as I really suffer with any heat.

Marty Bird

I’ll post my stats when I finish my run this Sunday.

Murph_D

I would not be afraid to take water with you in long runs in this weather - good flip belt with a couple of soft flasks. We hydrate during the race, no need to do long runs ‘dry’.

marathon2022

https://www.boards.ie/discussion/comment/120743697#Comment_120743697

Thanks Murph, I forgot to mention I had 500ml on the run Sunday past. At present I would use a simple rule of thumb( suitable to me, not recommending it for anyone else). A threshold or interval type session or anything over 10 miles easy and I take water.

Marty Bird

Just for comparison with the long runs, small run this morning.

Before: 69.4KG

After: 68KG

14km @ 4:36/KM.

Average HR140 a little high for that pace.

marathon2022

https://www.boards.ie/discussion/comment/120749417#Comment_120749417

1.4 kg down, the p&d book would recommend 2l extra hydration on top of your normal amount. So minimum of maybe 4 litres. A lot of water 🙂. Before I read this I wouldn't have kept track and more than likely not drank that much.

Marty Bird

Long run done.

Before: 69.4KG

After: 67.1KG

25km @ 4:26/KM.

Average HR146 again a little high for that pace but I put that down to having a few pints last night at a gig.

Murph_D

How long was the run?

Have to say I can’t imagine bothering to weigh before and after a run. I think if the session has been done to plan, it’s unlikely to require major intervention in the weight replenishment department. Sure, a good protein intensive meal for sure for recovery - scrambled eggs on toast is my go-to. And generally eating to hunger.

Open to correction. Always learning.

marathon2022

https://www.boards.ie/discussion/comment/120764952#Comment_120764952

Have you adhered to a P&D plan? The focus of my interest lies within the hydration chapter of the book. The chapter suggests a method of weighing oneself before and after runs in order to determine the appropriate amount of fluid intake (refer to "how much to drink," page 30, pages 30-34, third edition). I apologize for not providing a picture due to concerns of potential copyright infringement. If you happen to have access to a copy, you could refer to it briefly.

Essentially, in addition to your regular daily fluid intake, the recommendation is to consume 1.5 times the weight loss in kilograms during the run in liters of fluids.

For instance:

On Thursday, I engaged in a 5-mile recovery run while utilizing the Heart Rate Reserve (HRR) scale to maintain my heart rate at approximately 125 bpm. I experienced a weight loss of 1kg, with the outside temperature at 22°C.

On Sunday, I completed a 16-mile run, consisting of 8 miles at marathon pace with 4 miles on each side(130-148 bpm). During the MP my heart rate reached around 150 bpm, with the final couple of miles in the mid-150s. I lost 2.5kg during this run, with the outside temperature recorded at 20°C.

Based on the simplified calculation, I would need to consume an additional 2 liters of fluids following a slow and easy 5-mile run, and nearly 4 liters after a long run to replenish my hydration levels. I shared this information out of curiosity. Previously, I relied primarily on drinking to quench my thirst, but since I am following the P&D plan, I decided to read the book and consider the author's recommendations. Given the nature of the 6-day plan and the summertime conditions, I am striving to maintain optimal hydration in the hopes of enhancing my recovery process.

Murph_D

https://www.boards.ie/discussion/comment/120771183#Comment_120771183

Yes, I've done the P&D plan a few times but have to admit I did not follow that hydration advice too closely. In retrospect I didn't get the best out myself on P&D - overtrained if anything, but I'd put it down to lack of base conditioning rather than the nutrition/hydration. That said, I struggle with weight (losing too much) at the height of a marathon block and I find it hard enough to eat and drink enough to maintain a healthy weight. Will be interesting to see how you get on with paying more attention to these aspects!

marathon2022

https://www.boards.ie/discussion/comment/120777358#Comment_120777358

That was the one thing I was worried about on this plan, lots and lots of running at steady pace, also a near 25% increase in mileage on any previous plan. If it doesn't work out for me I plan on Hansons or one of the other popular plans next ;-)

marathon2022

Been busy lately so forgot about this till I read an article online yesterday. Seems the weighing pre and post run to help with hydration and recovery is widely known.

https://www.worldmarathonmajors.com/content-hub/fluid-dynamics?utm_campaign=July+2023+Newsletter&utm_content=July+2023+Newsletter&utm_medium=email_action&utm_source=customer.io

7. Weigh Yourself

Mild dehydration, consisting of losing at least 2% of your body weight in water, can negatively affect your run performance and result in symptoms of dehydration.

So, if you weigh 160 pounds, your goal is to drink enough that you weigh no less than 156.8 pounds at the end of your run. (Every pound you lose during your workouts signals 16 ounces of water gone, Williams explains.)

For the most accurate measurements, weigh yourself naked before and after your training runs. After runs, your clothes will be weighed down with sweat.

8. Go the "Extra Mile"

You don't stop losing sweat the second you cross the finish line. So, to fully replace any sweat losses, you need to drink more than you think within 90 minutes of your workout.

"It's recommended to drink 1.25 to 1.5 times the fluid volume that you lost," Williams said, adding, "For every pound (16 ounces) you lose in body weight, you should drink 20 to 24 fluid ounces of fluid."

Yesterday, I completed an 18-mile run with heart rate readings ranging from 139 at the beginning to 144 towards the end during which I maintained an average pace of 8:00 minutes per mile. During the run, I took 750ml of water, and since I wasn't feeling particularly energetic, I brought two gels and wore my alphaflys for an added boost. Additionally, I took a salt tablet before starting.

As a result of the run, I noticed a weight drop of 2.1kg. Following the recommendations from P&D (Pfitzinger Plan) I should consume an additional 3.5 liters of water on top of the usual 2 liters I would normally drink, amounting to a total of 5.5 liters throughout the day.

This marks Week 4 of my P&D training program, running over 100km for the first time. I'm hopeful that these efforts will aid in my recovery.

Annie get your Run

5.5 litres, that's a lot of water and it seems excessive to me. I don't own a scales so can't check what I lose on a run. Even if I could, I would struggle to drink even half that amount in a day. Did you drink the 5.5 litres and did it make any difference to how you felt or your post run recovery?

marathon2022

https://www.boards.ie/discussion/comment/120865358#Comment_120865358

I had the same thought when I read the book and did a couple of weighings around long runs. I suppose that was the primary driver for posting the query.

On a Sunday I find myself taking on at least 5l of fluid before, during and after long runs. About 500ml water in the morning prior, 750 ml water on the run, a 750ml bottle of sports drink straight after the run while stretching, then I open a 2l of fizzy water(juice of half a lemon in) which I would finish by afternoon. Then I try to take another Lt in the evening with meals etc.

I can't say for sure if it's helping and I am tired after long weeks doing p&d but other recovery habits like stretching and shoe choice for long runs also aid recovery.

I'm up over 100km for the week now for the first time in my life so anything that might help is tried

Posted from my phone so apologies for the messy prose

RickNally

https://www.boards.ie/discussion/comment/120866119#Comment_120866119

Hey there,

Just a quick note on this that might be helpful. While taking on fluids is one of the most important parts of rehydrating during/after a long run (or "prehydrating" before a run), a lot of articles or programs forget to mention the fluids that we get from eating solid foods. We've all heard that a typical person needs to drink around 2L of water per day, but the original research this is based on actually suggests 2L of fluid intake, most of which you'll get if you eat a balanced diet. So that 5kg weight drop from fluid loss doesn't necessarily mean that you have to drink 5L of water. A mix of solid foods and fluids can help to get back to your original weight.

Do you look to replace your salt levels as well as taking on water?

event

5 and a half litres of water a day? I'd never be out of the toilet!!

That seems a bit extreme to me tbh. I think people can get lost in the weeds about stuff like this

ger664

5 liters of water WTF I would up and down all night to the bog.

Please bear in mind when you run we burn a thing called Glycogen. It's stored in the body with 3-4 parts water.

The body is smart Burn one part glycogen body temp rises sweat 3 parts water body temp reduces.

On warm days there will be extra water required to cool the body so water and salt intake would be needed during that run to prevent dehydration.

Post-run replace the glycogen stores with a good healthy diet and sufficient water. Judge this by thirst not you need to drink 2/3/4/5/ Litres of water.

marathon2022

https://www.boards.ie/discussion/comment/120959929#Comment_120959929

5 liters a day is madness in the context of normal hydration but I wasn't implying this (see first post).

The topic was spurred on by the hydration chapter in the P&D Advanced Marathoning book with an emphasis on warm weather (which it was in June) longer runs so I posted to see others opinions and maybe get a measure of other peoples weight loss to make sure mine wasn't an edge case, which it seems not be . After I read the chapter and look further into it, is appears this is a very well established post run hydration technic, Have a gander at the article below.

https://www.runnersworld.com/uk/nutrition/a761780/rws-complete-guide-to-hydration/

Quoted from above- "Replacing fluid after a run is just as important. For every kilogram of bodyweight you lose, you need to drink one-and-a-half litres of fluid. Try to drink around 500ml in the first 30 minutes after your run and keep gulping every five to 10 minutes until you have reached your target. If you pass only a small volume of dark yellow urine, or if you have a headache or feel nauseous you need to keep drinking – a sports drinks or diluted juice (with a pinch of added salt) are your best options." seems to agree with this method.

Overdrinking could also be an issue as the article points outs but it would seem sensible that weighing before and after in circumstances like long runs in warm weather would give a measure of understanding of hydration levels to be replaced.

https://www.boards.ie/discussion/comment/120963328#Comment_120963328

There are many online studies and article on this, if you have a small bit of time you might find the one below interesting. My post and topic was related to a very specific part of the recommendation with regard to understanding how to re hydrate specifically on longer run days in heat where hydration levels are effected more than normal days.

https://www.triathlete.com/nutrition/are-you-doing-thirst-right-the-science-says-probably-not/

Lumen

https://www.boards.ie/discussion/comment/120989864#Comment_120989864

I have serious doubts about an article which references the "Gatorade Sports Science Institute (GSSI)" without any obvious signs of irony or discomfort.

Losing weight during a run does not mean you're "dehydrated" in a meaningful sense (of having performance or health impacted during the run), although gaining weight during a run would be a very bad indicator for obvious reasons.

On holiday I was running 15ks in mid-20s temps and found 500ml during was plenty. I've cycled in 40C temps before and got mild heatstroke even with plenty of drinking. That was bad. 40C is bad. Don't do 40C.

This is Noakes' 2012 article

https://www.outsideonline.com/health/running/tim-noakes-serious-problem-overhydration-endurance-sports/

I agree with drinking a decent amount after a long, hard run. That's obvious since glycogen storage requires water, but personally I just judge by urine colour.

marathon2022

https://www.boards.ie/discussion/comment/121005626#Comment_121005626

.....

Annie get your Run

I just noticed an estimated sweat loss stat on Garmin Connect! Never saw this before, I must look up how they calculate it. It's giving me 784ml for a 6 mile hill run this morning which I'd say is probably about right. Given how bad I am at hydrating in general, this might be really helpful in improving that..