Have you ever wondered if you could use a block period of condensed interval training to improve your cycling? After all, you’re not a professional cyclist. And if you were to try one, how often would you schedule intervals?
You may have already seen the research on the benefits of block periodisation of interval training. And the last six months of two interval sessions per week have brought you nowhere. You’re considering a block period, but you’re concerned about the risk of overreaching (rightfully so).
I was thinking about this predicament the other day when I decided to jot down some ideas on how to bridge the gap between traditional interval periodisation and your first block period.
Featured image: FiledIMAGE // Shutterstock.com
Before we dive into things, I should note that there are several interval parameters you could manipulate to tweak your training response. These include exercise intensity, effort duration and recovery periods. However, this post addresses the issue of when to schedule your interval sessions.
Two extremes of interval scheduling
Let’s consider the far ends of the interval scheduling spectrum.
On one side, you have the common amateur cyclist’s schedule:
Two interval sessions per week. This involves a mix of threshold and high-intensity sessions, perfectly aligned with the science of pyramidal training (1-2). This structure is repeated week in and week out.
The great benefit of this structure is that it’s easy and low-risk. It’s sustainable and promotes consistency. This drives development. Until it doesn’t – at some point, your progress will come to a halt.
On the opposite side, you have the Rønnestad block protocol, including five interval sessions within a single week (3). Then, the following three weeks contain a single interval session only. And so the cycle continues in a 1:3 weekly pattern.
When used for 12 weeks in trained cyclists, athletes on the block periodisation came out slightly stronger than those with the traditional pattern of two weekly intervals (3). When you crunch the numbers on all studies looking at block periodisation, it does indeed look like a promising method to improve performance (4-5). That said, not all studies find a difference between block periodisation and traditional periodisation (6).
Five interval sessions in one week are, of course, bonkers for the majority of busy amateur cyclists. But are there principles here that you could apply to harvest the benefits of block periodisation without throwing load management and recovery overboard?
I suggest there is.
The concept of increased intensity density
One reason block periodisation may work to improve performance is by providing an increased density of training stimulus. Simply put, you collect more minutes on threshold or high-intensity work over a given period of time compared to regular scheduling.
A few studies suggest that you can apply this concept even if you don’t do radical block periodising.
Tønnessen et al. found that when athletes performed two longer interval sessions per week, they achieved greater progress than athletes who completed the same intensity volume spread across four shorter interval sessions (7).
Greater density of intensity won.
In a different study, athletes who performed a single interval format only for four weeks before swapping format the next 4-week cycle outperformed athletes who used a mix of interval formats throughout the same period (8).
Both of these studies could be interpreted as supporting the value of compressing more training stress of the same character (of the same intensity) within a shorter time frame.
How to use this principle sensibly
If your performance is stuck with your two weekly intervals, here’s one way you could go about applying increased “intensity density”:
Say your weekly intervals are evenly spread out on Mondays and Thursdays:
- Monday: INTERVAL
- Tuesday: Easy day
- Wednesday: Easy day
- Thursday: INTERVAL
- Friday: Easy day
- Saturday: Easy day
- Saturday: Easy day
This leaves two easy days after Monday intervals and three easy days after Thursday intervals.
One way to increase the density of your interval stimulus is to schedule it for Monday and Wednesday instead. In theory, this could result in a more concentrated stimulus to drive the cellular adaptations you’re after.
- Monday: INTERVAL
- Tuesday: Easy day
- Wednesday: INTERVAL (added density of stimulus here)
- Thursday: Easy day
- Friday: Easy day
- Saturday: Easy day
- Saturday: Easy day
This would be a simple first step you could experiment with.
Before I continue, there’s an important caveat to consider. You still want to be able to execute your intervals with high-quality efforts (9). Scheduled too closely, before adequate recovery has occurred, your training stimulus will be blunted by decreased interval intensity (due to fatigue).
Further ways to condense stimulus
Let’s consider further progressions.
Imagine you go for our Monday + Wednesday solution. On the weekend, you often end up collecting some time on moderate and high intensity during a fast-paced group ride.
If you wanted to condense your weekly intensity stimulus further, you could opt for slowing down the weekend group ride. And instead, move that load to Monday’s or Wednesday’s interval by adding one more repetition to an interval session. Granted, that’s not always viable within a group ride, but in principle, this could work IF you tolerate the extended interval sessions.
More focused mesocycles
There are also further steps you could take if you wanted even greater density in intensity stimulus:
Instead of alternating between high-intensity intervals on Monday and threshold intervals on Wednesday, you could decide to do only high-intensity intervals for 2-4 weeks. And then, swap to doing only threshold intervals in the following weeks.
With this approach, there’s another caveat to consider. Any physiological property you don’t stimulate for some time, tends to retreat towards its baseline level. As such, if you’ve done 3 weeks of high-intensity work and aim for 3 weeks of threshold work, it could be worthwhile considering including a single maintenance session of high-intensity within your threshold period. This way, you could still increase the density of threshold work while maintaining the properties acquired from your previous high-intensity period.
Straight out block period
The final transition towards even greater intensity-density would be to experiment with careful use of block periodisation.
However, transitioning straight from two intervals per week to Rønnestad’s five interval sessions per week may quickly turn disastrous for most age group amateurs (my experience, no papers on this).
But, if your training base is strong and you’re already training with strong control of your load and recovery, you could experiment with miniature block periods:
Instead of doing intervals on Monday and Wednesday every week, you could distribute the intervals in a block pattern within two weeks.
In week 1, you do three interval sessions on Monday, Wednesday and Friday. Then, in week 2, you only do a single interval session on Wednesday. The result is the same bi-weekly training load as with two weekly intervals, except with a greater density of intensity work.
If you’re highly trained or an elite athlete, this principle could be extended to four and even five weekly intervals within a 2- or 3-week period. If timed correctly, and executed well, this could potentially drive greater adaptation if you’re stuck in the same interval routines week in and week out.
A word of caution
The challenge you’ll face when attempting this approach is to balance the increase in interval density with adequate recovery and load control.
Therefore, when you are experimenting with increased density in your training, I recommend you progress with baby steps. Make small adjustments only, carefully control intensity during workouts and always focus on achieving strong session execution. Indeed, the experience of coaches and athletes who succeed with block periodisation suggests that intensity control and quality in execution are key (9). If you fail to complete a session strongly, it’s likely a sign that you’re doing too much or not resting enough in between.
A stepwise approach to added intensity density
Here’s my pragmatic approach to increasing your interval density summarised. The assumption being that you’re starting from a point of weekly intervals with a mix of threshold and high-intensity work:
- First, ensure adequate load balance (you should be frequently well-rested)
- Schedule intervals closer together within a single week
- Focus on a single intensity/modality for some weeks at a time
- Add repetitions to the interval session (do so carefully to maintain point 1!)
- Experiment with a careful block period of frequent intervals within a 2- or 3-week period (re-distribute sessions for higher density within that period)
As a final word of caution, I must emphasise that I’ve seen a lot of athletes mess up their training by approaching the above steps too aggressively. You should only attempt these steps after you’re CONFIDENT that you’re in tight control of your training load and recovery.
But done correctly and in appropriate situations, these principles can be useful to nudge your performance upward (particularly in the later stages of race preparations).
Best regards,
Martin
References:
- Galán-Rioja MA et al. Training periodization, intensity distribution, and volume in trained cyclists: A systematic review. International Journal of Sports Physiology and Performance, 2023;18:112-122
- Magalhães PM et al. Effects of a 16-week training program with a pyramidal intensity distribution on recreational male cyclists. Sports (Basel), 2024;12(1):17
- Rønnestad B et al. Effects of 12 weeks of block periodization on performance and performace indices in well-trained cyclists. Scandinavian Journal of Medicine & Science in Sports, 2014;24(2):327-335
- Mølmen KS et al. Block periodization of endurance training – a systematic review and meta-analysis. Open Access Journal of Sports Medicine, 2019;10:145-160
- Solli GS et al. A microcycle of high-intensity short-interval sessions induces improvements in indicators of endurance performance compared to regular training. European Journal of Sport Science, 2025;25(1)
- Almquist NW et al. No difference between 12 weeks of block- vs. traditional-periodized training in performance adaptations in trained cyclists. Frontiers in Physiology, 2022;13:837634
- Tønnessen E et al. Interval training frequency on time-trial performance in elite endurance athletes. International Journal of Environmental Research and Public Health (IJERPH), 2020;17(9):3190
- Sylta Ø et al. The effect of different high-intensity periodization models on endurance adaptations. Medicine and Science in Sports and Exercise, 2016;48(11):2165-2174
- Karlsen T et al. Intensity control during block-periodized high-intensity training: Heart rate and lactate concentration during three annual seasons in world-class cross-country skiers. Frontiers in Sports and Active Living, 2020;2:549407
- Rønnestad B et al. 5-week block periodization increases aerobic power in elite cross-country skiers. Scandinavian Journal of Medicine & Science in Sports;26(2):140-146