Training & Nutrition - "Opening Up": Benefit or Bunk?

I've heard a lot of cyclists talk about "opening up" the legs the day before a big event by doing a short ride with some jumps or intervals. On the strength of these rumors, I've even done it myself. But I haven't seen any literature that explians why we do this.

Is there a real physiological benefit to doing a short ride with efforts above LT the day before a long, hard ride? What's really going on with the body?

I'm a big believer of opening up right before the race. My legs take forever to feel good in a ride so I was finding myself feeling good 20 minutes into a 30 minute crit. So why not try to simulate that first 20 minutes prior to the start and then my legs are ready and willing when it is time. It is pretty hard to simulate actual race intensity without a power meter..so what i usually do is ride for almost an hour before the crit and incorporate intervals and jumps.

As far as road races go, i just try to spin my legs 20 minutes prior as you have plenty of time to warm up on the road.

I've never particularly ridden the day before a race with the purpose of "opening up" the legs but I also usually treat the day before the race just like any other training day unless my legs are tired.

I've heard a lot of cyclists talk about "opening up" the legs the day before a big event by doing a short ride with some jumps or intervals. On the strength of these rumors, I've even done it myself. But I haven't seen any literature that explians why we do this.

Is there a real physiological benefit to doing a short ride with efforts above LT the day before a long, hard ride? What's really going on with the body?

I've done this a couple of times, and my (anecdotal) feeling is that if I don't do that (and just taper), I tend to feel a bit flat on the long ride.

The physiological explanation is that your body is more ready for the high-intensity efforts.

I'm a big believer of opening up right before the race. My legs take forever to feel good in a ride so I was finding myself feeling good 20 minutes into a 30 minute crit. So why not try to simulate that first 20 minutes prior to the start and then my legs are ready and willing when it is time. It is pretty hard to simulate actual race intensity without a power meter..so what i usually do is ride for almost an hour before the crit and incorporate intervals and jumps.

I've done the same thing before a time trial. If I don't warm up well for at least 40 minutes, my effort will be all over the map (well above/below LT) for the first ~10 minutes of the TT. However, I haven't noticed a great difference between my TTs when I do and do not ride the day before.

I used to worry about unnecessary glycogen depletion by riding the day before a long event, but I've read that as long as you (a) get plenty of rest and (b) take in plenty of carbohydrates, glycogen stores should replenish within 24 hours. Thus a short ride shouldn't be a problem.

But I'm still curious whether there's any real advantage?

For a bigger race, I'll take off the day 2 days before. The day before the race, I'll go on a relatively short, very easy ride. Maybe 10-15 miles to get lunch or some other sort of easy ride.

It doesn't work any magic, but it does seem to keep you 'loose' for raceday.

On raceday I need 12-15 miles prior to the start to feel like I'm ready to go. I think I take a little longer than most, but this does make a difference for me.