Analyzing MTB race results with power?

So we have a midweek race series that kicked off this month with individual time trials instead of mass start. So I have gotten to do about four races, 9-11 miles in length, 1000 ish vertical (47-55 mins ish). Start around 6000ft elevation. I train at about 4500.
My stats’ 311 ftp, 90.5kg
I’m seeing power of about 220 watts and about 290 normalized.
Speed is 12mph. HR avg 168, max 180 (41 yrs old)
How do I judge my performance? Should I be happy with these data or unhappy? What percentage of my ftp should I expect to achieve in a MTB race? To be clear, I’m taking 7th every race. As many as 7 minutes behind leader. So I already know I have room for improvement. I’m just concerned that I’m not hitting my current fitness numbers.
This is not to scrutinize my cornering or climbing or line choice. There’s minutes to be saved there. But am I hitting satisfactory power numbers?

    • What race category are you racing in?
    • How big is the field (7th out of how many)?
    • How long have you been racing?
    • How was your placing in previous race years (assuming same category)?
    • What power meter do you have on your MTB (dual or single side)?

What makes you think you’re not achieving what you should be? It’s difficult to use power data to judge performance for MTB racing. I raced with power all last year and never used power as a marker as it’s not representative of effort in MTB. Normalized Power is some indication I suppose but the 4 races I won last year my NP was no where near my FTP (although all my races were 1:15-2:00 hours long). To some degree you can analyze performance by looking at your power and if you went out too hard or faded towards the end of the race, but this is so variable because of terrain. If you have long hills you can see if you held a constant power or went out hard and burned out towards the top. Also think back to parts of the race where you wanted to push harder but couldn’t and look at your power numbers during those sections and preceding that. It could provide some insight for you to improve upon.

When racing I would all but ignore power during the race unless you have sustained climbs. Since it’s all TT races and you don’t have someone to race against, judging your performance will have to be a combination of placing in the field and a honest assessment of your effort. HR may be able to be used post race as well to provide additional insight. However, racing XC I can’t imagine your HR average was less than 80% of HRMAX at any time.

You can’t control who shows up to races and how they will compare to you. Since you have no-one to actually race, the race becomes against yourself. Control your controllables because you can’t do anything more. Analyze your race on what you can improve upon. Could you be more efficient, maintain speed, corner better, chose better/faster lines, pace better? Is your warm-up sufficient, did you pre-ride the course, are you mentally prepared? How was your fueling before and during (although your races are pretty short)?

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I’ve been looking a little bit at MTB pacing using IF (NP/FTP) since seeing it mentioned in the Keegan Swenson Everesting topic. As far as I can see it’s most valuable for longer races and as more of a cap for early effort.

MTB and especially hard and short XC racing is so variable and you will often just do the power required to get through whatever trail features present themselves. But, if you know what IF you can endure for your ~50min effort that could be a start point?

Just my 2 cents but I thought it was worth adding and I’m interested in other MTB pacing suggestions.

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How long’s the race in terms of elapsed time?

I’m racing expert. Last year raced sport and was podium in both appearances. There’s 8-11 in the expert class age 35-44. This is my third season racing and I’d imagine I’m racing a lot of veterans who are probably multi-discipline (cross, crit, fatbike, etc). So I am not expecting to win out if the gates.
Races are about 50 mins +/- 5. The leader was 41:20 and I was 47:10.
Power meter is a quark, single side.
There’s a lot about techniques in my time. I am aware of that. But i am just trying to get a sense for if I’m hitting decent power numbers in my post mortem analysis. Not monitoring it during race.
I think heart rate avg is pretty close to 90%. 161/179 is 89%. Did I typo above?
I’m not able to get on dirt much due to family so I’m definitely not going to get my technical skills polished this year. So I’m just trying to manage what I can control. And see if my expectations match up to my abilities.

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MTB racing even with 1,000 feet of vert is probably forcing you to surge a fair amount on short climbs and out of corners. Anytime you add variability you are going to see your numbers fall.

Take an old Cadillac and put it on cruise control across the Arizona desert. Set the cruise to 65 and the engine runs nice and smooth at 2,000 rpm’s. Gas mileage is probably about as good as it’s going to get at that speed. Take the same car through the Black Hills in SD and attempt to hold that same speed and your mpg is going to get cut in half.

If you averaged 12 mph for 9-11 miles you are racing something like 50 ish minutes. For 50 minutes your NP is 290 and your FTP is 311 so that’s 93% (IF). You have some room for improvement there but I would consider that to be a solid result.

If I had to guess the other 6 guys are probably lighter than you and if you have a fair amount of cornering they are reaccelerating faster than you and able to hold a higher average speed.

For your weight you can crank that FTP higher or lose some kg’s or maybe even both. I wouldn’t point to your NP/FTP (IF) as your primary concern to be honest. I think your results there are actually pretty solid and you are performing pretty well for your FTP. You can post a race file and we can take a look for you.

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Good morning,

I‘ve done some MTB ITTs on crosscountry laps in the past. What I saw was always a NP output ~10% below FTP for a one hour effort. Different pacing strategies didn’t play a major role. As said above: the track dictates what numbers are possible and reasonable (unless you knock yourself out at some point).

https://www.strava.com/activities/3661919044 here’s the actual race. note that the first 1.5 miles is pre-race. i didn’t think to stop and restart my recording. i don’t think it’s significant.
Thanks for all the feedback so far.
In trying to just address one variable, i am getting the sense that I did not have a particularly subpar performance and that is encouraging. I just wanted to get cross some things off my list so I know where to focus my improvement efforts:

  1. weight loss is key (i am definitely 20,30+ kg heavier than the other racers)
  2. I’m doing fine as far as power is concerned
  3. My initial concerns that i was losing time on the descents is true. THis is, unfortunately, the worst case scenario though.

Regarding 3. this is definitely bad. this has kind of always been my limiting factor. You’re supposed to never get passed on the descent. but looking at strava segment times, i am losing time to the leaders here. The pandemic and young children at home has reduced me to 1 outside ride per week, typically. hard to really practice my cornering and descents when that 1 ride is often a race.
I’m trying to take all of this in stride. I’m not expecting to win/podium in expert, but i am trying to maintain an eye on improvement.

Ah. i hadn’t thought about IF. Garmin says .98 for IF and that includes a few minutes warmup. so i guess that’s a pretty good answer.

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You’re not too far off from my experience. Last year I started off racing Sport and won my first 4 races and took 2nd in the 5th race for an overall series win. I then moved up to Expert for the last two races and took 7th and 6th with my second Expert race being a 2 lap TT.

For reference, last year I was 42, 6’1” tall with 298 FTP weighing 175 lbs (3.75 w/kg). My Expert races had about 15 racers and I was front of the mid pack. The top 3-4 finishers were well ahead of everyone else and belonged in Elite. So I’d say you’re right where you should be, so keep at it.

Thanks. this is encouraging.
I tried one race last year in expert, but flatted and (no surprise) was last. Even without the flat, i would’ve been last for sure. The courses overlapped heavily with last year 2 miles and 400 feet longer. My time dropped from 1:15ish to 47:08. The flat did not account for more than 6 or 8 minutes, i’d wager (just slapped a strip in there and co2 fill.
About a month later, i switched to Sport and took 5th and 2nd respectively. So i saw a similar experience to yours. Looking at sport this year, the courses are identical so my times would have put me in 2nd each race by less than a minute for each.
I don’t mind not getting on the podium (other than the 2nd place season total would score me a free season pass for next year). I’m still able to see improvment from last year, and can track some improvement week over week this year.

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Power on the MTB for XC is to look at the data afterwards, I might be echoing so forgive me if I am. I would think about all it the times you think you were losing time when power to the pedals was a factor. Was it the short punchy moves, a more sustained climb, power out of corners? If you can look at your power file over laid with the terrain you can get a sense of what energy system to target in training.

Average power for a MTB ride will always be disappointing, NP, while better is also not as valuable as compared to road. Instead it’s best to look at those key areas, I think about being able to quickly ramp up to say 500w even for just a few seconds to clean a tricky uphill and be able to repeat that, recover and go again. Repeatable power is also very important.

I bet based on your numbers you stand the most to gain from technique though. I know you say you’re challenged with adequate time to develop skills but when you do get out there to practice keep it super fun. Last weekend I had planned on an outdoor workout on the MTB but didn’t feel good enough to do threshold work so I decided to take the opportunity to hone some skills. There’s one 4 mile section of single track that I love riding, but it’s pretty technical, I decided to try something different and just do two laps on the same trail (I never do that sort of thing, but I should) after the first lap I felt really connected to my bike and decided to go for a PR. I got it, even though I wasn’t 100% I was still able to get to maybe 90% of my fitness that day and I focused on momentum preservation more than power output. That’s the beautiful thing about off road cycling, so much comes down to technique and not 100% fitness. It’s also the reason why looking at a raw power file after a XC race may not always provide with enough insights for improvement. Of course if you start throwing in sustained climbs over a few minutes long that can change.

Here’s the race profile. Note that the race started about mile 1.5. i neglected to stop/restart my watch after my pathetic little warmup.


Looks to me like I maintained adequate, perhaps not stellar power for the final climb (called Somewhere Elks). I dropped a cog or two and went with higher cadence on a sustained climb. I did hit a rock and stalled - something i consider evidence of fatigue. it was just short of the crest (shame).