Torwen:

Hello and welcome back to the Ideal Nutrition Podcast. Today, we’re doing an episode for athletes, coaches, and other dietitians listening. Specifically on nutrition for double training days. So, just reiterating who this is kind of tailored to. But, mostly those doing two longer and more intense training sessions within the same day. So endurance athletes, CrossFit athletes, team sports, or anyone who actually trains hard twice in a day. Less so people who do something like one strength session and one walk in a day.

Aidan:

Love that. Love the clarification. Because, yeah, sometimes I make a post on double training days. I’ll get comments from people who just don’t train hard. They’ll make a comment and say this doesn’t apply to me. And I’m like, so fair. It doesn’t apply to you. But yeah, I agree. So this is for people who train hard and train long. There’s a few things we can do to kind of optimise things. For improving performance in both sessions, and also recovering well for the next one. So we are going to go through quite a few things. We’re going to start by talking about refuelling.

The first place we’re going to start is glycogen. It is arguably our best fuel source for activity above a certain intensity. And if you’re training twice per day, and they’re long sessions, that matters. Even more so if you’re hitting the same muscle groups twice. Even if that is lifting and then running, for example. Or if you’re running twice, or whatever it is. There is a strong argument for replenishing glycogen stores as quickly as you can.

So you have more glycogen going into the second session. You can perform better in the second session. Then potentially that better stimulus can lead to better adaptation over time. Directly post-exercise, the body is more sensitive to converting incoming carbs into glycogen. We can take further advantage of that by having really easy-to-digest simple carbohydrates. It’s hard to give specific guidance here. Because it really does depend on your overall goals. That’s a common theme we’re going to talk about. This thing matters, but total intake does matter more.

I would say a good goal is having something like one gram per kilo of carbs per hour. That’s for the first few hours after exercise. If you’ve got really high workloads, I’d do simple carbs for the first one to two hours. Then switch to a more nutritious type of high-carb meal in general. The reason why I add that caveat is because what if that came out as the equivalent of three grams per kilo of carbs per day? And you were only aiming for three for the entire day? And you’ve just had that all in a few hours or something like that. So you would obviously have to tailor the space to your situation.

Torwen:

I like the number one gram. I think that is easy to remember and easy to implement. Most of the time, that works pretty well. Whether it can be that combination of fast-digesting carbs, and potentially from a meal as well. That works pretty well. In terms of protein, then we talk about protein for muscle repair.

So, another really important aspect of refuelling is supporting that muscle repair as quickly as possible. To support muscle protein synthesis, which speeds up recovery and adaptation from both sessions. Here, I like to go for around half a gram per kilo body weight. Within those first three to five hours is normally a pretty good guide. Or having something like a snack with 20 to 30 grams of protein afterwards.

Aidan:

Absolutely. People can debate how much this matters. I still do lean in favour of it actually mattering a little bit. It matters far less than total intake. But it still does matter a little bit. That is my interpretation of the research. And I’ve read a lot of research as well. Another stance that I have seen, through the lens of this not necessarily mattering heaps, is this. People have made the point like, well, let’s say you’re aiming for enough total protein intake.

And you didn’t do this. How are you going to hit that? If you’re aiming for 1.6 grams per kilo plus, do the maths on that. And you weren’t eating before or after your sessions. And you train twice in a day. When are you getting all that in? So it makes sense, even if you’re just caring about total intake. To do this as well, just from a logistics standpoint.

Torwen:

I guess when we talk about rapid repletion of glycogen, and supporting muscle repair, the last R is replenishing fluid. Hydration is often overlooked. And in double training days, it’s potentially even more important. If you start that second session already dehydrated, performance is likely to drop. So making sure that you drink regularly makes a lot of sense. Replacing around 150% of fluid loss in those hours after training.

Aidan:

If it’s a really tight turnaround, let’s say four hours or something like that, I’d even consider adding electrolytes to this. It is as simple as this. If you chart how much water or fluid people are absorbing per hour, there is a difference. One version has straight water. The other version has water plus sodium. The one with water plus sodium typically absorbs a little bit more of that water. Which would obviously matter a little bit more for this.

I think all athletes should just be well hydrated all the time, where possible. But even in elite sports, across all sports, our dietitians do hydration testing. If they say they’re going to do it every week, but they do a surprise one the first week, so many athletes show up dehydrated. If they come in next week, everyone’s hydrated. So it is just a good friendly reminder.

Torwen:

Timing of food becomes important. We’ve just mentioned a few things that we think are important to get in around a session. As well as making sure that you reach total energy and protein requirements. That can be hard. So I do like to say, ideally, getting three balanced meals plus snacks. Then that additional carb-rich pre-workout is important. And ideally, what to get in along with those extra carb snacks afterwards too.

Aidan:

And closer to training, you want things to be easy to digest. So you want low fibre and low fat. Noting that this is a bit individual. Some people could tolerate a bit more of those things. Some people could tolerate a little bit less. The goal is just to have it so that you’re feeling good. It doesn’t feel like it’s sitting super heavy in your stomach or anything like that.

We’re talking about protein around sessions. There is an argument that you could benefit from some level of protein before. Particularly if it’s like two hours before the session, or whatever. The closer it gets to the session, the less likely I would recommend that. One downside of this, particularly if you’re doing it twice in a day, is this. If you’re going with simpler carbs, easy to digest, both before and after, you start missing certain stuff.

And I think the next name of the game is this. How do I make up for the rest of that stuff throughout the rest of the day? How do I get more micronutrients in? How do I get more fruits and vegetables, just in general? How do I get more fibre alongside that? More wholegrain options? How do I get more healthy fats? So on and so forth. So suddenly now, the timing even matters for your meals that are not around your sessions too.

Torwen:

Especially when, like we said, lower fibre often means you need to eat a lot of that fibre at main meals. More so than at other times of the day. Along with tacking on iron-rich food sources, those protein sources, and maybe calcium and dairy as well. Which can come in as a nice after-training snack too.

Aidan:

Absolutely. You can see why I get more excited about people who are training twice a day. There are so many more things that still matter. I’m not saying when you train once a day, stuff doesn’t still matter. But some of you just have to be a bit more particular about this stuff if you want to optimise it.

Torwen:

We’re going to run through whether we think it’s important to do any sort of periodised intake. What that refers to is periodising intake with training phases. To optimise outcomes like fat metabolism, glycogen storage, and potentially gut function. It often moves beyond generic recovery advice, which we’ve just spoken about. So carbohydrates after and around training. One of those is training high and sleeping low. Aidan, what are your thoughts?

Aidan:

Yeah. So what we’re talking about is the traditional gold-standard way. But the train high, sleep low kind of approach is this. If you’re training twice a day, you could do some sessions in a high-carb state. Some sessions in a low-carb state. The training high part is, hypothetically, you did a session in the afternoon. Ideally, that is an intense session. And you’ve had heaps of carbs coming into it. Then after that session, you have almost no carbs and you go to sleep. So you’re sleeping low, so to speak. Then you do a fasted or low-carb session in the morning the next day.

Which ideally is a lower-intensity effort. The reason why they would structure it that way is this. One, getting those adaptations you spoke about. In terms of fat metabolism and mitochondrial adaptations, there are benefits to being in a low-carb state. Even just elaborating on that, high carb tends to outperform low carb a little bit in the research. But not as much as you would possibly expect. I would actually even make an argument that not as much as high carb outperforms moderate carb. That’s partly because there are some adaptations that occur in a low-carb state.

Researchers have obviously looked into whether we can get the best of both worlds. One thing that doesn’t seem to work is just going low carb. Then having heaps of carbs before a race and during a race. People don’t tolerate the carbs very well. So the logic is to get a bit of both. Why they would do it low intensity and high intensity is this. Let’s say you’re a runner and you’re doing intervals. If you do that in a low-carb state, you might not hit the same paces. Particularly later in the session. You get less of a stimulus for adaptation.

But if you’re doing a zone two run, you are going to hit those paces regardless. So doing it this way kind of allows you to always hit the intensity you’re meant to be hitting. But you could potentially be getting some more adaptations in the low-carb sessions. Which is the logic they are getting at with this.

Torwen:

I haven’t read too many studies. I had a look at a few acute trials. They did show an upregulation of lipid oxidation markers. That was versus someone who had that fed recovery state. But not necessarily changes in mitochondrial function. That’s an interesting one by Lane et al. I’m sure there are other ones out there. Any that you wanted to mention specifically?

Aidan:

So, the first thing I did want to mention is this. We’ve spoken off air about our preparation process for podcasts and stuff like that. We obviously put a lot of work into this. I’ve said off air just before that one of the last things I do is go to AI. I don’t go to AI first. But I don’t want to miss it completely. Because there is value in it. The reason why I don’t want to go to it first is this. Sometimes it would make me more lazy with checking other stuff.

Secondly, it can kind of lead you in odd directions. And something I’ve noticed more and more over the last few months is this. If I ask the same question to AI, it gives me different answers on different days. Even if I use the same model. Very different. I’ll use this example before I talk about this. I was looking at endo and creatine. One day it was kind of like, yeah, it makes sense for women with endo to not have creatine.

Then the next day, same kind of question, it was like the risk is pretty low. I was like, geez, if I was a woman with endo, I would be very concerned by that. What I was going to get at with this is I did the train high, sleep low stuff. There are times I’ve put it in and it has been like, no, it’s not beneficial. It’s like the research shows that it doesn’t matter. Then other times it’s been like, it absolutely matters. It’s something that improves performance for sure. A lot of elite athletes are doing it. They’re doing this concept of fuelling for the work required.

Which is a bit more of a nuanced way of doing this, and so on and so forth. But looking at research, this is 2021 that I was looking at. Obviously, there’s a bit more research now. But there was a meta-analysis looking at nine studies on the topic. That found no improvement in performance. That is the metric I care about. That is the outcome that I care about. That therefore means, at best, if there is an improvement, it can’t be a large improvement. Because it would be showing up there. At worst, it can’t be making people worse.

So, in terms of where I kind of stand, I do actually see potential for it. I wouldn’t rule it out for people. Particularly if somebody is enjoying it and has personally found benefit from it. I think, go for it. I do also stand by my at-worst kind of statement. There are many people who have a super early morning session. It is a low-intensity thing, and they don’t like eating before it. And I’m like, all the power to you. This shows you that you don’t need to. It’s fine.

I think you can pick and choose. I do still stand by this. If you’re doing intense sessions, you should probably carb up before that. Whether it’s the day before or the morning of. I’ve got one more thing, or two more pieces of nuance. I’ll go through. One, it could be a more complex way of achieving the same outcomes. It definitely makes easy sessions feel harder than they need to be. This absolutely shows up in the research.

I think it massively slides under the radar. There are people doing these zone two runs and they feel like trash doing it. But they’re hitting the pace. But it’s like, well, this should be easy. It’s called an easy session. So it makes things harder than they need to be. There is also a little bit of concern about RED-S. I don’t know if you had thoughts on that.

Torwen:

Not necessarily.

Aidan:

No, I don’t know where I fully stand on this. I think this can be misled by the fact that people with low carbohydrate intake might have lower calories as well. But the current consensus does seem to support the fact that there is research showing this. Carbohydrates specifically can be protective against some issues associated with RED-S. Therefore, more so working with a female athlete population, particularly if they are at risk of underfuelling, I am a bit cautious. Cautious of this idea of saying just go for it.

Like, if you want to do a fasted run, go for it. There should be a little bit of caution applied there as well. But if RED-S wasn’t a factor for you, and just confirming that stands for relative energy deficiency in sport, then I would stand by this. You could also make a case that this approach isn’t worse. So, although everything we’ve spoken about has been gold standard, so to speak, if you did lower-intensity sessions in a lower-carb state, that could also be fine.

Torwen:

And bringing it right back down, total energy and nutrition intake across the day is most important. If you’re struggling to get that, and you’re not refuelling after sessions, potentially this isn’t for you either as well. Any other thoughts?

I have another thought in terms of generally fuelling for double training days. It does take a bit of preparation and planning. Because it’s a lot of food. It’s a lot of thought about what you’re having prior, during, after, and between sessions. So if possible, getting some advice and input is always positive, I think.

Aidan:

Absolutely. Taking everything we spoke about with the train high, sleep low stuff out of it, I do think this can be one of the simplest ways to improve performance. There are so many athletes I speak to where, when they start implementing this, their second session of the day is so much better.

Their general health and energy levels improve as well. Because we haven’t even spoken about this. Refuelling after that first session makes you feel better throughout the day. If you train twice a day, you probably also work a job in the middle of the day. You probably feel way better with this as well.

Torwen:

Anything else you want to talk about?

Aidan:

We’ll wrap up there. So this is episode 252 of the Ideal Nutrition Podcast. We talked about nutrition for double training days. As always, if you have not left a rating and review, we would massively appreciate it.