Is this regression normal?

This fall towards the end of my season I was splitting about 23-23.5 for 40k, which was a huge improve on my 21.5-22 the year before. Anyway after this season was over I took about four weeks off; a little longer than I wanted but things got in the way and I took about 4-5 weeks off of cycling. Now, I’ve been slowly getting back into cycling again and put in about 4-5 hours the last three weeks mostly just fairly easy spins, but did intervals once both weeks. Anyway today I did my first FTP test and my results were 19.5mph on (somewhat soft tire) on KK fluid road. My wattage, according to the formula by KK was about 244. Should I be worried about this loss of where I was or is this about an average loss for how long I took off? And if so, at what point, when should I get worried and reevaluate my trainer workouts?

How do you know how much power you lost? Have you compared your last season FTP test on the trainer to your current 19.5? You won’t get an accurate estimate of FTP from your splits in a race, so you can’t really compare race splits to trainer performances.

I use a KK road trainer for my hard intervals and training as well. After about 3 weeks off after last season my FTP on the trainer went from 22.53 mph down to 22.05, so roughly 15 watts lost.

How do you know how much power you lost? Have you compared your last season FTP test on the trainer to your current 19.5? You won’t get an accurate estimate of FTP from your splits in a race, so you can’t really compare race splits to trainer performances.

I use a KK road trainer for my hard intervals and training as well. After about 3 weeks off after last season my FTP on the trainer went from 22.53 mph down to 22.05, so roughly 15 watts lost.

I don’t…I actually started using power this winter. Last year was my first year in triathlon so I really didn’t know/care about power/watts anything other than speed. ha. I just wondered if you’d be able to get a measure of how much fitness I lost. I know this isn’t a lot of information and i’m probably missing important stuff like you state above. I just didn’t know if this was normal or not to get this much slower or what i feel is so much slower.

If you aren’t racing anytime soon, I don’t think there’s anything to “worry” about with lower numbers this time of year. My highest FTP by the end of the 2013 triathlon season was 287, took all of November off, and when I tested for base training in December, it was 245. Rather than compare your current FTP to your last in-season FTP, compare it to your FTP this time last season. My first FTP test in January was 228, so I know I’m in a good place despite having lost 42 watts from peak.

There was a video interview recently on training on a trainer. They had Leanda Cave and Tim Don as guests. AdventureBear was the host
Tim said that he easily loses 25 watts when he becomes a “fatty fatty bum bum”
Leanda jokes that she would struggle doing 150watts when she normally does 200 for long long rides.

I don’t think those numbers are accurate or scientific, it’s just to say even the pros lose watts.

I personally find the short duration interval watts come back first,

— I took about four weeks off; a little longer than I wanted but things got in the way and I took about 4-5 weeks off of cycling. —
^^ THIS ^^ is the reason.

As they say, “use it or lose it.” Unfortunately, aerobic fitness and endurance deteriorate rather quickly. 4-5 weeks off the bike will be quite noticeable. Don’t worry too much, however, it will eventually come back if you put in the time.

Don’t worry about how much fitness you lost since there’s no way to know (or even if you could determine it). Worry about gaining fitness from where you are now

Were the improved speeds you were seeing on roads during a race or on the trainer? I would never take any stock on speeds while riding a trainer. Actually, you shouldn’t bother looking at that number ever while on the trainer because its irrelevant. Focus on power and HR numbers, the rest will take care of itself.

edit: you also need to lose some fitness to get better year after year. Continually trying to improve won’t work in the long run if you don’t take breaks every now and then. Just focus on getting better from where you currently are., as others have said.