Drop in MAP numbers

Is it common to see a drop off in MAP after 6 weeks of non-structured outdoor only rides?

Structured training started in earnest in January and I was pleased with an increase of 10 - 12% across the board since my initial 4DP

HM in early April completed 409w on ramp before stopping (382 MAP; 307 FTP). Continued with a mix of Suff workouts and outdoor rides through April and May.
Suff workouts mainly MAP / AC type intervals e.g. revolver, the shovel, the cure, joyride, the trick. I found these hard but achievable based on the HM numbers and felt I had made further improvements.

Since June rides have been outdoors only, average 100 - 150 miles per week. Mix of 2-3 hour tempo / threshold rides, a couple of long endurance rides and a couple of hard efforts on club “fun” TT’s (10 mile solo and 23 mile pairs). Average speed has generally been up with lots of Strava PB’s.

HM ramp tonight, found anything above 300w tough and packed in after struggling through the 374w step (345 MAP / 37w drop).

Disappointed and a bit disheartened with the result if I’m honest. Felt okay and well rested but don’t really enjoy indoor rides in the higher summer temperatures.
Also wondered about possible calibration issues and if I should’ve completed a spin down on my Kickr beforehand. Perhaps that’s just wishful thinking.
Maybe it’s just a simple lack of focus on MAP targeted training.

Anyone else had experience of this?

It’s very common to see a drop in your numbers when you stop doing structured training. That’s just how it works.

I always calibrate my trainer before doing a ramp.

Fitness is one of those things where if you don’t use it you lose it, I’ve seen drops of upto 25% in MAP following a months inactivity.
Article here has some explanations
Detraining: The truth about losing fitness | Cycling Weekly

But sounds like you have been riding plenty, so my guess is that is that you’ve either been overdoing it on the outdoor rides and you are fatigued and need to rest, or you have been missing that top end intensity on your outdoor rides and your MAP really has dropped as per the link above.

Do you have a power meter on your outdoor bike to see if you have been hitting your MAP numbers outdoors? Do you monitor fatigue via HRV or TSS?

Are you in the UK? The heat has been intense, ramp test indoors in this would be crazy unless you have A/C

@JGreengrass no not got a power meter on the bike so any efforts are RPE / HR based. Most of my rides include a hill or two ridden at a reasonable effort which I thought would sustain MAP levels. Perhaps a bit fatigued but had 4 days off the bike before trying the HM.

@Jim yeah, west coast of Scotland though so nowhere near as extreme as other parts of the UK. Mind you anything over 18.deg feels pretty extreme to me. Did find it uncomfortably humid but enough to result in a 10% drop?

Hopefully just a combination of the above and a bit of an off day. I’ll maybe try again in a week or so and if the results are similar I’ll just need to knuckle down to the intervals again.

Based on the description of the writing you have been doing, it would have been surprising if your MAP didn’t drop. When shifting towards outside riding, higher volume, and lower intensity, you’re going to see a shift in your 4DP profile. When you remove that high intensity from your weekly training, you’re naturally going to see a decrease in those capacities.
That’s not necessarily a bad thing. Especially if your goals for riding outside are to go longer/further/keep up that tempo pace for longer durations.
The training you’ve been doing is called reverse periodization. Meaning you start off the season with higher intensity and lower volume. As you transition to riding outside with a higher volume, the overall intensity has to drop.
Starting your outdoor season with a better aerobic ceiling meant that you could ride at that base tempo or sub-threshold intensity at higher absolute power. That higher power means higher training load and ultimately means greater improvements in your ability to maintain those sub-maximal efforts.
With an increase in volume, there is always going to be a risk of increased fatigue. How rested were you going into this Half Monty test compared to your previous Half Monty test?
Riding at tempo or sub-threshold intensity exacerbates the fatigue you’ll experience from increased volume. That blunts your top-end power. It’s possible you were overly tired or not rested enough going into Half Mony this time around. Was your peak 1-minute heart rate lower for this more recent test?
As you mentioned, and others have pointed out, the calibration on your trainer could be a factor here, especially if the ambient temperature in your pain cave was higher for this test than the last time you tested. We’d always recommend calibrating your trainer before doing any fitness test of any training session that will push you right to your limits.


Hi, I had exactly the same experience. Mainly doing indoors for some 6 months in the Covid lockdown period improved all my 4DP scores by approx 20%. Thereafter doing mostly outdoor rides, and after about 9 months of mostly outdoor rides, my MAP score is down by 10%, whereas all the other three dimensions are even slightly better than before… I must however say that my outdoor performance of long fast rides with my friends ( 3 hours plus) is the best ever, despite the drop in MAP??


Thanks @Coach.Mac.C for your comprehensive explanation. It’s certainly possible that I wasn’t as rested as I had thought. I did have 4 complete days off the bike beforehand but the ride prior to that was a 2up TT. My partner was a strong rider and I was on my limit for an hour (to even hold his wheel at times). Max heart rate for the HM was 167 compared to 172 in April but it felt more like a lack of strength in the legs that caused me to stop.

@philip.potgieter I could understand a 10% drop after a significant time away from indoor training but it was only 6 weeks and if the results are correct then my MAP levels are right back down to my January 4DP starting position.