Indoor Cycling: Train Low-Sleep Low For a Better FTP This Winter?

This week, we explore how daily carbohydrate manipulation can enhance endurance training adaptations in trained cyclists.

Specifically, can cyclists increase their FTP (functional threshold power) by eating the same amount of daily carbohydrate (CHO) but timing intake differently?

The concept of 'train low' has been around for a while: The depletion in muscle glycogen during exercise while withholding CHO post.

It's important to note that a 'train low' diet is not a low CHO diet. The rider will still consume adequate amounts of CHO based on their daily needs; however, CHO is distributed within the day differently.

It's been shown that a reduction in muscle glycogen can activate certain adaptive pathways associated with enhanced endurance adaptations.

A hallmark measure of enhanced adaptation is the greater amount and efficiency of mitochondria in the muscle and, therefore, an improvement in fat utilisation.

Therefore, the cyclist can use more fat for fuel during prolonged, sub-maximal cycling. In return, sparing muscle glycogen.

In theory, this can improve higher-intensity performances during more intense phases of a ride/race when under normal fuelling conditions.

That being said, RPE and training quality during sessions may worsen due to training under low CHO availability. However, poorer training quality could be an acceptable compromise for the enhanced molecular adaptations to the muscle.

Although this sounds very promising, the translation of these enhanced adaptations to 'real world' race day performances remains limited.

Bennett et al. (2021) investigated the nutritional impact of 'train low-sleep low' (TLSL) in trained cyclists. The TLSL programme consisted of three phases:

1. In the evening, complete a high-intensity ride (6x5 min at 105% FTP) to deplete muscle glycogen by approximately 50%.
2. Withhold CHO post to 'sleep low' and enhance the adaptive response (not recovery).
3. Perform a lower-intensity fasted ride in the morning (1 hour at 75% FTP) under low CHO availability.

This home-based training protocol was performed thrice a week on consecutive days for three weeks during the COVID-19 pandemic (lockdown).

This training method was designed with a more' real-world' practical application for cyclists who have time constraints and typically train indoors during the winter months, using apps such as Zwift or Trainer Road.

The participants cycled up to 1-1.5 hours of low-intensity rides daily for the remaining three days of the week.

The control group and TLSL were provided with a 6g/kg CHO diet (but ate ~5g/kg). The control group evenly distributed their CHO intake throughout the day, whereas the TLSL group followed the below schedule:

• RIDE: LIS fasted
• Breakfast: 2g/kg CHO
• Lunch: 2g/kg CHO
• Mid Afternoon snack: 2g/kg CHO
• RIDE: HIT
• Dinner: 0g/kg CHO

Following the three week training study, the cyclists retested their FTP. Both groups improved with the TLSL protocol having superior results:

• Control = 272W pre to 275W post (1.3%)
• TLSL = 271W pre to 282W post (5.5%)

Despite RPE being consistently higher in the TLSL, 5 min power improved in both groups to the same extent; however, 1 min power plateaued in the TLSL, where it improved in the control.

Based on these findings, a 'train low-sleep low' protocol may be worth considering to enhance the efficiency of your training plan and gain greater adaptations when the time available to train is limited.

Assuming this protocol aligns with your food preferences and levels of food focus at meal times, I recommend exploring this option, especially if you already perform twice/day sessions.

However, this approach wouldn't be appropriate or applicable for the rider who doesn't have time constraints and can perform large training weeks as they'll promote a robust adaptive response via the same mechanistic pathways, even when fuelling with high amounts of CHO.

We recommend fuelling the ride for these riders to ensure they can complete more high-quality sessions and hit their targeted weekly volume. Ultimately, time in the saddle is the most potent method of improving your fitness. However, if time is tight, especially during the winter months, we now have options available to enhance the adaptation further and get superior results, without having to do any extra work.

- Coach Chris