What should I be doing??

What are your riding goals?

Jason

At this stage I'm looking to increase my fitness and endurance

Commute

I was and am in a similar condition. My weekday training is limited, however, I do get to rack up some good training time on the weekend.

I have progressed fairly well considering my limited time during the weekday and I used to use the spin bike based on a similar condition that you are in now. What helped me the most was understanding training principles and how those impact metabolic adaptations. On the its killing me.....thread on this forum there was a nice discussion, but here is a web page that helped as well to understand and to apply. What I like on this page is that Dr. Coggan added to the chart perceived exertion (RPE) and a description of how that feels.

home.trainingpeaks.compower training levels, by andrew coggan.aspxOpen ↗

I used this for a couple years before I was able to buy a power meter. It is the principles that is the most important aspect. The power meter only helps one hone in on the levels, but one can use the descriptions while using an unmonitored stationary bike. If you have a stationary bike that has watts that is good as well, but just note that the reading on those may not reflect the same as a bike with a calibrated power meter. Doesn't matter though since the bike will probably be consistent to itself.

Last week I used a Precor bike at a YMCA while traveling and it was reading 100 watts while it felt more like 240 watts.

The more limited your time is I would suggest going more for the top of Level 4 with 2 - 20 minute efforts. If you have a full 60 minutes or more you may want to do more SST type work, which is an area between L3 and L4. From what I have been taught, it is important to do at least 15 minutes solid of constant effort. The longer more constant timed session the better if you are in L3. (Of course the interval time will be shorter for VO2Max/L5 efforts or higher. I tend to keep my training in the aerobic zones)

The web page link above can be really useful to understanding how to train, regardless of available time, but when you are armed with knowledge of the principles of training for metabolic adaptations you can begin to shape your own specific training plan.

Here is another web page that I think explains it well and better than I can do. It is about working on your Functional Threshold.

flammerouge.jefuncthresh.htmOpen ↗