As humans with a goal or purpose we like to know that we are making progress and moving in the right direction. To this end athletes and coaches have worked on developing the tools to quantify what we do and that we are indeed making progress. Over time this developed into an attempt to predict the future and tools such as the PMC (performance manager chart) were born.

Owning the tool and understanding how to use the tool are fundamentally different. It is understanding the tool and how it relates to it's specific reality, in this case how chronic load of training causes adaptation in the athlete, that make the tool valuable. With the PMC it has long been my observation that there is a disconnect between what we think we see on the screen (blue going up indicating improved fitness, blue going down indicating dropping fitness) and what is actually happening with the athlete's, or our own performance in real life. 

Initially we seek to make that blue line (the one we've come to associate with fitness) go up, and indeed if we are new to structured and consistent training we find that as that line goes up we get fitter. Initially. After time we start to discover that it's not quite that simple, and line going up sometimes means we go slower, even once we taper back. We also find that sometimes we improve when the chart tells us we are losing fitness. As a short term tool, and especially with anyone new to consistent training, we can say there is a fair correlation between blue line up and fitness up. For everyone else we need a smarter understanding of how the human body adapts over time, when fitness actually declines, and what makes one athlete's 100 CTL that much faster than another athlete's 150 CTL.

In very basic terms I see that "time spent at a level" is a much better indication of actual fitness and performance potential than the blue line having gone up. An athlete who has lived at a constant, lightly undulating range of say 75-105 CTL for 3-4 years will pretty much always outperform someone who is at 130 CTL but got there in just 6-12 months before which time they were living at a level between 10 and 30 CTL. It's time spent at a certain habitual level of stress that creates longterm and meaniningful changes, not the short term radical attack over a few weeks or months. Consistency is the big player when it comes to fitness.

If we move away from the chart and think purely in athletic terms. Let's say we choose our favourite pro athlete to analyse their data. Let's say for arguments sake that they are a top marathon runner. They run 100 miles a week, nearly year round with some undulations in volume but rarely dipping below a 70 mile week and rarely peaking above 110 miles for a week. They've done this for the past decade, and we have to recognise that it is more about the decade consistently running 100 miles most weeks, more than the single act of running 100 miles in a week, that has made them who they are as an athlete.

Now take me, let's assume I take up running more seriously. I've done it for a while and I've typically average 30 miles a week. I decide to add 10% each week and "get serious".

Week 1: 33 miles

Week 2: 36 miles

Week 3: 40 miles

Week 4: 44 miles

Week 5: 48 miles

Week 6: 52 miles

Week 7: 57 miles

Week 8: 62 miles

Week 9: 68 miles

Week 10: 74 miles

Week 12: 81 miles

Week 13: 89 miles

Week 14: 98 miles

Week 15: 100 miles

OK, it's been 15 weeks and now I'm running as many miles per week as our favourite pro runner. So I'm just as fit right? Duh... Everyone knows the answer right? The pro is fitter, and a much faster athlete, because he's been running 100 miles every week consistently, for a lot longer than I have.

The PMC chart and how we can use it to predict fitness is exactly the same from my experience. It's not hitting a number that makes my fitness. It's the weeks, months and years of consistently sat above a number that have the biggest bearing on how fit I become. When I raced Elite XCO I was very rarely ever below 80 CTL. When I moved to 24 hour solo and started winning them I rarely ever dipped below 100 CTL. There were periods of upslope quite close to a race of caused by the races themselves. There were periods of downslope where I was training EXACTLY the same as the period before the upslope and still imprioving my fitness. I was constantly keeping the bucket of training stress topped up. 

This is my chart for 2024. It peaks out at 128 CTL but the average is 89 and it's that average which is the important number to establish and work on. 

Which brings us back to our old friend: CONSISTENCY.

Consistency builds everything, by stealth, it's very obvious but it's not very sexy. We don't get fit enough for ultra racing by doing massive rides and having lots of rest/being broken for long periods of time between them. We get really fit for ultra by consistently sending small and slightly challenging signals to the body telling it to change. We can see a radical change of short lived performance by battering ourselves with Vo2 max intervals, but it's short lived and form dips radically not long afterwards. However we can consistently give ourselves a hard session, maybe once or twice week for a short period, or once a week for longer periods, and see constant improvements. We can starve ourselves and lose a lot of weight real fast, but it's usually all coming straight back on, in nearly as short a time, and often brings with it a bit of extra weight just for good measure. However we can consistently make very good dietary decisions and we will end up, and stay at an ideal bodyweight and healthy fat level. 

Consistency.

It's boring.

We try to deviate from it, but it is the sure fire recipe for pretty much anything we want to achieve in our own little sphere of sport and performance. The PMC chart is the same if we want it to predict how fit we are. Rather than looking for peaks we should look for troughs, and in future years try to minimise the troughs to some extent. Flatter blue lines, but at higher average levels, are what deliever and predict high fitness in my experience. Look for the averages over time and send those higher rather than stressing over the short term changes and undulations. 

Of course there are caveats and ways to mess up the chart. The first thing we have to be sure of is that we always set FTP correctly and that we update it regularly. I prefer to use a 1 hour effort as my marker rather than a 20 minute test, and I never use a ramp test. Personally I know that I have 1-3 minutes of power that compares to the top 5% of my age group worldwide. I can skew a ramp test very easily. I can even skew the 20 minute test. 1 hour and that physical gift is not going to touch the data in any meaninful way. FTP has to be set correctly because it is the anchor for generating all the TSS numbers and knowing ourselves is key to knowing if we set it well. 

Second thing to know is that consistency is a more powerful driver for change than inconsistency or to be perfectly blunt: big rides and lots of time off. 10 x 1 hour sessions creates better fitness than a 10 hour ride on the weekend and then 6 days off. BUT they both produce the same change in the PMC chart. So big rides can skew the data and we need to consider this. From my observations I reckon that anyone with a ton of big rides in their data (consistently going  over 4 hours) needs to knock about 20-40 CTL off their average to compare to what their average could be if they were consistently training 5 days a week or more instead. 

Third thing: crap in = crap out. If the TSS score was produced by group riding and it's a load of messy spikes of data, and there's loads of anaerobic efforts, then it's probably skewed the data a lot and will give a false high compared to training to build a bigger aerobic engine.  

Forth... If we stop a lot whilst out riding then the metabolic demand is a lot different to a constant effort. Group rides, especially off-road, are really good at skewing a chart. I've worked with athletes one-to-one where the only thing I've changed is to get them to ride alone more and not stop anywhere and their performance has gone through the roof on exacty the same volume and intensity of training as they were doing previously.

...and lastly number five: specific stimulus creates specific change. Yes, running can make us better at the marji bike, cycling can contribute to a good Marji run, and yes regularly lifting weights can aid in our task to absorb and survive the Marji through to the finish, BUT they only make a worthy contribution if we are hitting the baseline requirement for the actual sport we are participating in. If we are short of time then we should always ditch everything but our main sport(s), the one we will be racing, if we want the best results and outcome from our race on limited time available to train. Cycling makes us good at cycling. Running makes us good at running. Everything outside of our sport is a BONUS not the main driver of performance. This is a critical consideration for the PMC chart. I have lost count of the number of accounts I've analysed where the athlete can't understand why they can't complete or compete in their main sport, and when I remove everything but their actual race sport we discover that there is nowhere near enough of their main sport being trained. For the purposes of my own PMC, as a bike racer, I adjust my strength, and recreational sports to 1 TSS per session (If I even record them at all) I set running at whatever is lower between rTSS and hrTSS, and I cut down my long rides TSS to <250 TSS if I've not been consistently training my main sport around them. I find my chart is very predictive and reliable to how I might perform.  

So, to recap: A tool is just an object until we understand how to use it. The PMC is better thought of as an check for averages over time. Good data in = good data out. House keeping with data really matters a lot. Specificity is very important to improvement in our key sport and Consistency is KING when it comes to increasing fitness no matter what the blue line does.