midtoad's messages

You may well ask, if I can’t feel my legs, how can I tell whether the exercise I am doing on my FES bike is overdoing it or not? Good question. I use a couple measures to help me determine I level of fatigue:

1.  if the level of stimulation goes up to 100%, and then the automatically controlled resistance begins to reduce and reduce and reduce, that’s a sure sign that my legs are getting tired.
2. When I am doing an intense interval with manual control of resistance, then the machine will not reduce my resistance even if my legs are getting tired (though the RPMs will fall). In this case, I can look at the average power per lap during the session and see whether it was falling towards the end. Also, I can monitor my power output during the exercise and see whether it is stable or decreasing.
3. In addition, when I do more than one session of the same type I can monitor whether my power output was higher in the second session than the first, or whether it is beginning to decline with each succeeding session. A variation of this, when I am doing an easy session, is to see whether the level of stimulation required increases in each successive easy session.
4. Lastly, though I can’t feel the skin on my legs, it seems that after an intense workout my brain can sense that the legs are tired. There’s a heaviness that I don’t sense prior to my workout. This is fascinating, because my injury is considered complete, which means my brain receives no sensation from nerves below the entry level. How is it possible then that I can sense fatigue?
5. Related to this, if I had a really hard workout, afterward I find that I cannot stand in my chair for very long without my consciousness fading away. When I am fresh, I can stand much longer.
6.  If I have pushed too hard during a workout, when I stop, my blood pressure may fall precipitously and I will bonk seriously. If I have trouble remaining consciousness after a workout, that’s a sure sign that I have overdone it.
7.  And finally, if I do two identical workouts several days apart and experience much worse results on the second workout, that’s a sign that I am either fatigued, or coming down with a cold, or something similar. It’s a clear indication that I should take it easy for the next couple of workouts.

There are a few graphs from today’s workout illustrate my points.

In the graph above, the black line shows average power per lap during this session. Average power was higher in the second left in the first as my legs got used to the level of work required, and was only 10% less in the third lap. After a 15 minute break, the average power during the last lap was nearly as high as in the second lap. Conclusion: in this session, fatigue is not an issue.

Well now, let’s look at the two easy sessions I did during this workout. In the first, below, the stimulation level (blue line) rose to nearly 100% and then stayed fairly constant around 95%. In the second easy session, further below, the stimulation level only rose to around the 80% level, indicating that my legs were not worn out yet. However after two hours of riding, I was ready to take a break!

LSD (long slow distance) session 1:

LSD (long slow distance) session 2:

Any questions?

Tags: exercise, FES

Well, if I keep riding an FES bike, I might have to reuse the title of this post a few more times in the future. but still, I did enjoy a great ride on Saturday this week.   I have learned that I enjoy my rides more, and often get better results, if I mix it up a bit and don’t simply do the same thing for my entire workout. So in this latest workout, I actually logged four different sessions in succession. First, I did a 20 minute warm-up where I gradually increased both stimulation level and RPM, so my muscles could slowly get warmed up and get used to the stimulation level. Then, I moved on to interval training to work at a high, intense, level. After half an hour of that, I dialled it back and took it easy with some LSD [long slow distance], where I tried to recover my energy with some nice easy pedaling. Finally, one last blast with the interval training, which is where I achieved a new record energy output.  More on that below.

Here’s how the warm-up looked:

My idea for the warm-up, as outlined in a previous post, is to slowly increase both speed (green line) and resistance (magenta line) so that that the stimulation level (light blue line) gradually increases up to a maximum of 100% at or near the end of the 20 minute warm-up.  On this day, I hit the 100% level after 18 minutes, and the machine did not substantially reduce the resistance during the last two minutes of the workout. My average power (black line) during the last step of the warm-up was around 20 W, while maximum power (black dots) was around 22 W.  Warmed up muscles: Mission accomplished!

After one intense interval session, as I mentioned earlier, I took it easy for a while. Here is what that easy interval looked like:

At first, I had the resistance sent too high, so the machine rapidly increased the stimulation level to 100% and then had to begin reducing the resistance so that my legs could keep up. In the second lap, I got smarter and reduced the resistance. Then the machine slowly increased the resistance level but it never got to 100%. As you can see the average power output was higher in the second lap than in the first lap.   Now I was ready for one last intense session. Here’s what that last workout session looked like:  

I did four laps, each one at the maximum resistance of 20.75 Nm and the maximum speed of 55 RPM, followed by 30 seconds of taking it easy. Each successive lap, my average power output increased, with the last one being at 77 W. My overall energy output during this session was over 55 KCalories per hour. That is equivalent to an average of 64 W over the 20 minute period.   After my nearly 2-hour workout, I was both happy and tired, and ready for a nice cold beer!   Final word: as always, I owe a huge debt of thanks to my fiancée Julie, without whose assistance none of this would be possible.

Tags: exercise, FES