Aligning Your Nutrition With Your Training Goals
Standard sports nutrition recommendations, such as those cited in popular cycling and endurance sports literature, are generally geared towards optimising performance. A key example is the recommendation that for all exercise that lasts longer than 1-hour, you should consume carbohydrates both before and during the session (Potgieter 2013).
However, the goal of training is not usually to optimise performance. We’re usually not looking to hit PBs in training sessions. Instead, we’re looking to stimulate adaptations that will, over time, result in improved performance once the fatigue from training has been shed. Therefore, standard sports nutrition recommendations aren’t always appropriate when we’re looking to optimise training adaptations rather than performance.
A key example of this is low-intensity endurance rides, where a common goal of these sessions is to improve fat oxidation capacity. However, fuelling with carbohydrates before and/or during these sessions (as recommended in traditional performance-focussed sports nutrition guidelines) can sometimes undermine this training goal by shifting fuel use away from fats, towards carbohydrates.
As the body only has quite limited stores of carbohydrates, day-to-day nutritional recommendations have also traditionally favoured high daily intakes of carbohydrates for cyclists with high training volumes (Burke et al., 2011). However, more recently there has been increasing research interest in the concept of ‘dietary periodisation’ (Burke, 2015). This is the idea that daily macronutrient intake (i.e. the relative proportions of fat, carbohydrates and protein in your diet) is tailored to meet both the energy demands and intended purpose of the day’s session and wider training goals, rather than seeking to provide optimum performance in every session.
In our view, dietary periodisation is a better approach to day-to-day nutrition, especially where weight loss is sought, as it allows for a calorie deficit to be achieved by manipulating macronutrient intakes to suit the daily training demands.
With that in mind, this article aims to lay out some key tips for fuelling your training sessions, bearing in mind the goals and energy demands of differing sessions. We cover three areas:
Nutrition around training sessions
Day-to-day nutrition
Nutrition for weight loss
Nutrition around training
The table below provides some key tips for fuelling around your training sessions. A more detailed discussion follows further below.
Interval Sessions
For any high-intensity training sessions (i.e. those that involve riding at or above your threshold power), energy will be derived mainly through carbohydrate metabolism. In order that you can achieve the high power targets needed for these sessions, we recommend fuelling with a carbohydrate-based meal/snack beforehand. Ideally, this would comprise 1-2g of carbohydrates per kg of body weight, and should be eaten 2-4 hours before the session to avoid any gastrointestinal issues and to allow time for your blood glucose levels to stabilise before beginning exercise.
In relation to the above, many athletes train in the morning before work, and it’s not always possible to eat 2-4H before a session. In these circumstances, we recommend consuming a small carbohydrate-based snack or drink 5 to 10-mins before the session, or even during the warm-up. While it takes some time for these carbohydrates to reach your blood stream, they can provide an immediate boost to your subjective energy levels when receptors in the mouth detect the carbohydrates and send a signal to the central nervous system. Examples of snacks that work well immediately before a training session (i.e. which are low-volume and easily digestible so as not to cause gastrointestinal problems), include a sports drink, bar or gel, a banana, a slice of jam/honey on toast, a smoothie, milkshake or fruit juice, or some dried fruit or fruit loaf.
We recommend avoiding eating between 10-60 minutes before a training session, because after eating you will generally have a rapid rise and then fall in your blood glucose level before this stabilises. Beginning exercise during this period of lowered blood glucose can make exercise feel subjectively harder, and for interval sessions this is something we want to avoid as much as possible, because these sessions are tough at the best of times!
You might benefit from having some caffeine around 20-60 minutes before an interval session. This can help make a session feel subjectively easier. Tea, coffee, coke, caffeinated energy drinks, gels or gums and tablets can all provide caffeine in appropriate amounts.
Drink to thirst during these interval sessions, bearing in mind that your sweat rate can be high if you’re training indoors. Dehydration can make exercise feel subjectively harder.
After completing an interval session, we generally recommend having a snack within ~30-mins of the session. This should ideally comprise carbohydrates to replenish your muscle glycogen stores, and ideally some protein to help with repair and generation of new proteins in the body. This 30-minute window is when your muscles are most receptive to carbohydrates and the muscle’s glycogen stores will be replenished most effectively. However, eating outside this window will still help replenish glycogen stores, so don’t worry if you miss this window!
An exception to the refuelling guidance above is if you’re planning to do a carbohydrate restricted ride the next day in order to increase the stimulus for adaptations linked with fat oxidation (see here and here for more information on this strategy). In this case you can restrict carbohydrate intake after an interval session, sticking mainly to protein and fats in your post-workout meal(s). We wouldn’t recommend doing carbohydrate restricted sessions like this more than 1-2 times per week though due to the risk of inadequate total energy intake when following this strategy. For this reason, we’d also recommend avoiding this nutritional strategy entirely if you already have a very low body fat, are susceptible to illness, or have low bone mineral density and/or symptoms of RED-S (see below).
Endurance Rides
We define endurance rides as any ride that lasts more than 1H and is typically done predominantly at a Zone 2 intensity (~55-75% FTP), possibly including some Zone 3 intensity (75-95% FTP). These rides are predominantly fuelled by a combination of fat oxidation and carbohydrate oxidation. The extent to which you favour fat vs carbohydrate oxidation depends on your genetics and training status (plus some other factors such as prior fuelling, environmental conditions and time of day). Even the leanest cyclist will have sufficient fat to fuel exercise lasting several days, but the body’s carbohydrate stores are in much shorter supply – enough to fuel around 1.5H of all-out exercise.
Shorter endurance rides generally don’t require any specific fuelling considerations, as the intensity will be low enough and duration short enough that your fuel stores will be minimally impacted. That said, we’d recommend avoiding eating too much in the ~1-2 hours before a session to avoid gastrointestinal problems, but beyond that, you can eat as convenient.
Shorter endurance rides (up to ~2H) can be good sessions to employ carbohydrate restricted training, if this fits with your training goals. See here and here for more information on this.
Longer endurance rides may require some fuelling during the ride. The amount of fuelling needed depends on your ability to use fats for fuel. You’ll get a sense of how much you need to eat during these rides with practice. Given the low intensity of these training sessions, approximately 30g/hour of carbohydrates is a good target for many people when rides are between approximately 2 to 4-hours. If you’re riding for longer than this, and/or you know you tend to burn carbs at a high rate you can aim for slightly higher intakes in the region of 45-60g/hour.
We don’t generally recommend consuming carbohydrates at rates that greatly exceed your individual requirements, because this will tend to shift your metabolism towards carbohydrate rather than fat oxidation, whereas a key goal of endurance rides is typically to improve fat oxidation ability. Thus, consuming excessive carbohydrates can undermine this goal. There are some exceptions to this, however. A key one is if you need to eat during the ride in order to meet your overall energy demands. This might occur if you’re riding for most of the day, in which case you won’t have much time before/after the ride to make up the calories you’ve burnt. Other examples include athletes who already have a very low body fat, are susceptible to illness, or who have low bone mineral density and/or symptoms of RED-S (see below). In these cases, it’s safer to consume higher carbohydrate intakes.
Group Rides
Group rides are generally more intense that a typical endurance ride, and are usually focussed more on performance and enjoyment, rather than promoting specific adaptations. These rides will likely include high-intensity portions where energy is mainly derived through carbohydrate oxidation. These rides are also often long, meaning you may be at risk of depleting glycogen stores. It’s therefore advisable to ensure you have a carbohydrate-based meal or snack before these sessions, and also consume carbohydrates regularly during. See the table above for guidance on amounts and frequency.
Recovery Rides
These rides are short (generally 60-min or less) and low-intensity, generally being fuelled predominantly by fat oxidation. Accordingly, there are generally no special nutritional considerations for these sessions, and you can eat as convenient around these sessions.
Day-To-Day Nutrition
A varied and well-balanced diet has arguably the biggest part to play in allowing you to continue to train consistently and effectively.
A detailed discussion your day-to-day nutrition is beyond the scope of this article. However, we’ve set out below some general guidance around energy and macronutrient intake, as well as some things to be aware of.
Energy Requirements
It can be hard to reliably estimate your daily energy requirements. It’s also tedious and time-consuming to track your energy intake daily, so we think the best gauge of whether you’re meeting your daily energy requirements is to monitor your body weight (and ideally body fat) to ensure this is remaining stable, or declining slowly if you’re aiming for weight-loss (see below). You can also pay attention to your mood, training motivation and energy levels as these can all be signs of inadequate energy intake.
One helpful tip, if you use a power meter, is that the work done during a ride (in kJ) will equate almost exactly to the number of calories burnt in kcals.
So, if you do 1000kJ of work on the bike, then you’ll have burnt around 1000kcals. Knowing this can help you identify days where you may need to eat more or less than the norm. (Note if you’re riding off-road, energy expenditure might be higher than is indicated by your power, as you’ll burn calories negotiating technical/rough terrain in addition to those burnt pedalling).
If you really do want to track your calorie intake, then you can estimate your requirements using an online calculator such as this.
We recommend using a calculator that allows you to input percentage body fat, as the relative proportions of fat and muscle that make up your total body weight strongly impact energy expenditure.
Most energy expenditure calculators allow you to pick an activity level in order to work out total energy expenditure. We recommend picking an energy level that corresponds to your NON-TRAINING activity level (e.g. if you work at a desk, this will likely be low-activity/sedentary, even if you train lots). This will give you an estimate for your baseline energy requirements, to which you can add the calories burnt in your daily training.
As an example, you may calculate that your daily requirements as a female who is sedentary outside of training, is 1800kcals. Then if you did a training session burning 600kcals, then your daily requirements overall would be around 2400kcals.
Macronutrient Requirements
The table below shows approximate macronutrient requirements for different types of training day. These will need to be tailored to meet your energy demands, alongside training goals, but should provide a useful starting point.
Again, we don’t advocate continual tracking of your macronutrient intake. However, it can be helpful to record what you eat over a few days using an app such as MyFitnessPal as this will help highlight if you’re a long way above/below the recommendations for any macronutrients.
Risks of inadequate energy intake
It’s worth noting that when training volume is high, some people find it hard to replace the large amount of calories burnt. Others may intentionally restrict energy intake in order to keep body fat low. Over time this can lead to inadequate energy intake (meaning energy intake is not sufficient to support regular bodily functions alongside training). This can result in a condition known as RED-S (Reduced Energy Deficiency Syndrome in Sports), which can have a negative impact on training and both mental and physical health (Mountjoy et al., 2014).
Key warning signs of inadequate energy intake include rapidly decreasing body weight (more than 0.5kg/week), low on energy, mood and/or motivation, and in females, irregular or missed periods. It’s important to ensure you’re getting adequate energy intake to support your training sessions, and you may need to focus on incorporating more snacks within your day to help you achieve this. If energy intake has been low for quite some time, you may have RED-S without experiencing any weight loss. If you think you might be at risk of RED-S or suffering symptoms, we recommend consulting a doctor or a qualified sports dietician/nutritionist.
Nutrition for weight loss
An area we get asked about often is how to manage weight loss alongside training.
By far the most important thing to understand is that weight loss should be a slow and gradual process.
This is not only because aiming for rapid weight loss may compromise your ability to train and may result in loss of muscle mass, but also because rapid weight loss can kick off energy-conserving processes, where your body begins to suppress non-essential functions (e.g. the menstrual cycle in females). This can result in reduced bone mineral density, hormonal disturbances, increased risk of injury and illness and other negative physical and mental health conditions. This change also doesn't immediately reverse once you stop restricting food intake, which makes it hard to maintain any weight loss, as your baseline energy requirements will have been suppressed. This is one of the key reasons for 'yo-yo' dieting where people lose weight and then put it straight back on.
A safe rate of weight loss is around 1 lb or just under 0.5 kg per week. This corresponds to an energy deficit of approximately 500 kcals per day. In order to achieve this deficit while supporting training, we’d generally recommend cutting down fat intake closer to 15-20% of total energy intake. You can also aim for lower daily carbohydrate intakes, provided fuelling around the training session is sufficient to meet the session goals (see below).
We’d encourage you to keep intakes of protein and fibrous foods such as vegetables and legumes high, as these foods are satiating (help keep you full) and the protein should also help minimise loss of muscle mass.
In the final section of this article, we’ve summarised some specific guidance on how to adapt the guidance above with weight loss in mind.
Interval Sessions
With these sessions, we think that nutrition in the 2-4H before is the most important thing to focus on; aiming to get 1-2g/kg body weight carbohydrates within that window so that your carbohydrate stores are sufficient to allow you to hit the power targets required.
If possible, it can be good to try to time your meals and training sessions, so that you have a main meal falling within that 2-4H window, rather than needing to have an additional snack beforehand.
Outside that 2-4H pre-training window, you can reduce your carbohydrate, fat and energy intake. In particular, given that the next training day is likely to be either an endurance ride or a recovery day, then getting a high-carbohydrate recovery meal/snack right after your interval session is not critical, and you can just wait until your next regular meal to eat, or consume a low-calorie snack if you’re hungry.
Endurance Rides
As we've discussed previously, there's a benefit to doing these sessions with restricted carbohydrate availability, as this may augment the stimulus for fat oxidation. Restricted carbohydrate sessions can also be a good way to reduce your daily kcal intake.
For shorter endurance rides (1.5H or less), we don't think there's an urgent need to have a recovery meal right after your ride, so you can just wait until your next normal meal or snack, and this doesn't necessarily need to be particularly high in carbohydrates, as the session probably won't have impacted your glycogen stores very much.
For longer endurance rides (>1.5H), particularly if done with restricted carbohydrate availability, we do think it's more important to get a carbohydrate-based meal/snack in afterwards (aiming for 1g/kg body weight), because your glycogen stores and blood glucose levels are likely to be quite low, which can compromise your immune function if these remain low for extended periods.
Recovery Days
Although your energy expenditure is likely to be lower on a recovery day, we wouldn't overly restrict energy or carbohydrate intake on these days, because this is where most of your training adaptations will take place, and we don't want these to be impaired by having inadequate energy availability. Additionally, you are quite likely to have an interval/hard training session the following day, and will need to be adequately fuelled for that. It's fine to aim for the 200-500kcal energy deficit on these days, but take care not to go too far beyond this.
References
Burke, L. M., Hawley, J. A., Wong, S. H., & Jeukendrup, A. E. (2011). Carbohydrates for training and competition. Journal of sports sciences, 29(sup1), S17-S27.
Burke, L. M. (2015). Re-examining high-fat diets for sports performance: did we call the ‘nail in the coffin’ too soon?. Sports Medicine, 45(1), 33-49.
Mountjoy, M., Sundgot-Borgen, J., Burke, L., Carter, S., Constantini, N., Lebrun, C., ... & Ljungqvist, A. (2014). The IOC consensus statement: beyond the female athlete triad—relative energy deficiency in sport (RED-S). British journal of sports medicine, 48(7), 491-497.
Potgieter, S. (2013). Sport nutrition: A review of the latest guidelines for exercise and sport nutrition from the American College of Sport Nutrition, the International Olympic Committee and the International Society for Sports Nutrition. South African journal of clinical nutrition, 26(1), 6-16.