This is a really good point and I think was just covered in the latest podcast on bonking. I do find it odd how Tim Noakes is referenced a lot on the pod e.g. Waterlogged when now his whole fascination is low carb as a means of driving performance. For me it’s now very clear, I need carbs and lots of them.
This is a very good point and perspective. I think my point was not about fasted rides but about doing high intensity work on a limited, not very low, carb diet which from the experiments I’ve done is not suitable to performance.
200g a day of carbs is not really “low carb”. But if you reduced carbs from say 500g to 200g a day, did you replace the missing calories? Eg reduce carbs by 300g you need 1200kcal extra per day from fat and protein to compensate.
First off Tim Noakes is a joker, I would take nothing he says seriously.
The science shows in general you are better off with eating more carbs for better performance.
Of course with any study (especially nutrition) there are going to be outliers.
There is a reason MOST top endurance athletes don’t restrict carbs for any extended period of time.
hey John, just wanted to share my experience, as I also got on the carb cycling train for a bit, as it was recommended by some respectable coaches, but it didn’t work well for me.
I wasn’t trying to lose weight, but was told to eat less carbs as I didn’t need them if I wasn’t riding as much on Monday or Friday, a recovery day.
But then my Tuesday workout wouldn’t be totally 100%. Something seemed off.
I got back to always eating carbs, but they have to be nutrient dense and a variety…I love rice, but too much and I don’t feel 100%. I’ll try to mix it up, rice, potatoes, fruit, bread.
Carb loading for big mega days or races, and leaning my diet towards carbs the day before high intensity, and I haven’t found a reason to go on and off a carb routine.
From athletes I’ve spoken with and raced, no one at the front of the race is doing low carb.
Good luck with your riding!
I have 2 x take aways here but most of below is just my N=1. I have no scientific background or professional racing experience etc. Just thought it would be good to hear from someone doing a similar program.
I have found that build phase isn’t the time to be targeting weight loss. The main priority should be ensuring your body has enough fuel to complete the workouts, and also enough macro and micro-nutrients to recover and recover well. This may mean that your weight remains stable and/or you increase a little as you build more muscle mass, retain more water etc.
Base phases are a good place to target body composition changes e.g dropping a few kg’s. A lot of the base Endurance sessions you can target fasted and can really tighten your diet. That isn’t to say that fasted rides have no place in Build - I ride fasted in the Sweet Spot and Tempo sessions in GBHV program, but I always make sure that I have pasta the night before, and a banana and toast the morning of, a VO2 or Anaerobic session in the program.
I have found that body composition changes happen naturally in the Build program depending upon your genetics and the way your body handles the training stimulus etc. My weight has fluctuated quite a bit in the program as I have built up muscle but lately I’ve lost a few kg’s mainly because I have been adding on low IF Endurance extensions to sessions to build up FatMax etc.
Nutrition in Build is huge. You are basically breaking your body down to build it back up.
This by @toribath97 below
The benefit of training? Mitochondrial biogensis. More Mitochondria = more glucose uptake. Rest week = more chance for those good ol’ Glycogen stores to be restocked. Just like a Supermarket at night. The shop closes and all the punters go home, and the night fillers come in and re-stock the shelves ready for the next morning (AKA the next week of VO2 and Threshold workouts). Glycogen loves water.
A few studies that I have read lately about sustainable weight loss, have been about the fact that a lot of the rapid weight loss that occurs on low carb diets and after really high intensity sessions may be because of depleted Glycogen stores and the water weight that comes with it. The moment you load up on carbs the Glycogen stores, and the water, comes back with it. Interesting stuff.
So basically you have trained hard and depleted Glycogen stores etc. Then you have altered your diet and not let those stores build back up again (knowing and accepting that in rest weeks you generally will put on a bit of weight as the stores build up and water follows), and then gone into an FTP test with super depleted Glycogen stores. Unfortunately, something has to give - performance.
Muscle glycogen is maintained just fine. Not 100% sure on early transition period, but chronic low carb athletes have similar amounts and replenishment-rates of muscle-glycogen to carbed-up athletes. The liver however does not refill with glycogen, so that’s a few hundred grams of glucose and quite a bit more water – gone quick, but comes back quick as you note.
Also, the reduced insulin levels signal the kidneys to excrete more sodium. Water goes where the salt goes, so you lose a bit of fluid (and weight) that way.
Whats the reason for dropping weight? Often people get way too hung up on wkg. I’ve been there myself, looking at power to weight ratios, spreadsheets, how 1kg less weight give you an extra 30 seconds.
I looked around at the people i was racing with and kept wondering why i wasn’t dropping everyone given i probably had a full watt/kg more than them. w/kg makes little difference to most courses most people race. It helps for climbing mountains, power climbs are what most race courses have. Grand tours are really the only place there are that many proper mountain stages.
You need to focus on power. Better power means better in cross winds, flats, etc which is what most of a race is. If you’re FTP is only 270, you’re always going to be at a disadvantage on the flats and short climbs.
A year ago, i was 64kg, FTP about 310, not great but not terrible either. I was decently lean, but to stay like that required constant under fueling, and i just plateaued. Was stuck at that same power for a long time, and always thinking about food because i was always hungry.
Now, i’m closer to 68kg, FTP around 350 eating a lot more. Wkg not really that different. All my numbers are better, I can hang around on the cross wind sections, and still be there for the last climb. I gained 30-40 watts in about 6 months after being at the same level for maybe 2yrs.
This is a fantastic response in this thread! Really puts things into perspective.
It makes sense what you say. Unless you’re going to be riding up the Col Du Galibier or Mont Ventoux as part of your racing, W/KG is less of an importance than first thought.
Just to add my opinion on targeting both sides of the w/kg balance…
If my calculations are correct, for me:
adding 10w to my FTP increases my w/kg by 0.13w/kg
losing 1kg of weight increases my w/kg by 0.04w/kg
So, unless you’re really stuck/optimised in building power, I’d stick with focusing on performance rather than weight loss.