Can anyone explain why the first under after a rest period feels so damn hard?
I rode Kennedy -1 today and was surprised to find that my RPE for the first under of each under/over set after the recovery period was higher than the actual over that followed.
A forum search turned up a few threads about the first interval of a set feeling the hardest, but nothing that appeared to explain what I experienced.
I’m using ERG so I know I’m hitting the power targets consistently, but my legs just felt like they were full of concrete in the first under of the second and third set. The sensation lasted pretty much the whole under. The following over? Fine. The next under? Also fine.
I think I can rule out apparent gradient as the start of the second interval was uphill but the third was downhill.
Firstly, since you’re doing in ERG mode in Zwift, the gradient makes NO difference. Well, the only difference is the speed at which the virtual bike is travelling. So terrain plays absolutely no role - and that is ideal for structured training.
We’re all different. So that might just be your body struggling to get going again after a recovery period. For me, the first set of intervals is always hardest. But it’s almost as if my mind goes “okay now I know what’s coming - been there, done that” and from the second set I’m fine.
What MAY play a role as well (esp in ERG) is that you relax too much in your recovery and your start with a low cadence in interval 1 of each set. If that is the case, just consciously spin up just before or as you hit the start of the work interval, even though it’s an “under”. (I know because I sometimes tend to completely switch off during recoveries! :D)
I should clarify the gradient thing - I mean in terms of an unconcious perception of effort based on visual stimulus. I notice that sometimes on a virtual uphill in ERG my cadence increases by itself as if I was downshifting in prepartion for the climb, even though I know perfectly well I’m in ERG.
Returning to the workout for a moment, I made sure to return my cadence to my normal interval spin about 5-10 seconds early, but maybe I should try making the switch a bit earlier still.
I think there is some wonky ERG mode in Zwift with the uphills and downhills, slightly easier on uphill portions and slightly harder on the downhills. I have no idea why it is this way but believe I’ve seen it mentioned other places and feel like that’s been my experience.
I always find the first interval after the initial rest portion hard. Don’t know if it’s some of the lactic acid in the muscles that didn’t get worked out or what but always takes a couple minutes to stabilize
I feel it but I have written it off to my brain thinking the downhills should be easier when it’s the same power. Just like pedaling faster on the uphills with no speed gain.
Your muscles need oxygen to function. That oxygen is shuttled around the body via blood according to need. The heart is the pump delivering that blood but of course the heart does not respond to need INSTANTLY. (hence the important difference between anaerobic and aerobic fitness.) It takes a short while for the brain to register increased load, for the heart to ramp up to speed and get the needed blood to the muscles. During that lag it feels awful because you’re not fully fueled yet, your heart rate is still rising to meet the effort and the muscles are not fully supplied yet. Your body is drawing down more anaerobic systems to bootstrap you until the aerobic systems catch up. So it feels way harder because it IS way harder. Your muscles are working with less than the full supply of oxygen they need. Once the heart catches up you feel much better because the muscles have the supply they need and you’re off to the races!
It also makes me wish (for a moment) that the last recovery minute was a ramp up, right up until I realise that the first under feeling awful is just as important a stimulus as the rest of the interval. Maybe even more so.
Absolutely. Some TR workouts do have ramp ins and I definitely find those easier. But as you say, it’s a different stimulus and worth training the “hard start” systems.
Also, a detail I didn’t include in my first response which may seem obvious now… the reason you only noticed this in the 2nd and 3rd interval is that you entered your first interval from zone 2 so your muscles were already reasonably well supplied and warmed up. Interval 2 and 3 though came out of an easy zone 1 recovery spin so there was more work to be done to get up to threshold power.
