Quote:
Originally Posted by LisaS
I've read to be up and about for 30 minutes.
|
Eric Cressey seems to agree with you!
http://www.tmuscle.com/free_online_a...B953C73F.hydra
Quote:
Time of day is also significant with respect to injury risk potential, as there's a diurnal variation in spine length due to the in- and outflow of the fluid within the intervertebral discs. At night, while you’re lying horizontally and the spine isn’t loaded, fluid enters the disc; when you wake up and start moving around, fluid begins to leave the disc. By the end of the day, you’re actually shorter!
Oddly enough, you’re safer in the "short" scenario. The increased fluid content present when you first wake up is associated with increased stiffness of the spine when you bend (because the discs have expanded). Because the muscles can’t just adapt to compensate for this alteration to spine length, the discs and ligaments take on more of the stress.
Body temperature is also lower upon rising, so range of motion (ROM) is compromised even further. As the day goes on and you move around more, body temperature increases and the fluid flows out of the disc, improving ROM and reducing ligament stress. McGill (2004) noted that in the morning, disc-bending and ligament stresses during forward flexion were 300% and 80% greater than when performed later in the day. Moreover, lumbar flexion ROM increases by 5-6° during this same time period (2).
Basically, you need to give your spine at least thirty minutes in the morning to "wake up," and I’d prefer that you wait at least three hours to train. This recommendation is largely based on the increase in body temperature that you experience in this time. The data from Armstrong presented above actually shows that maximal grip strength and body temperature peak at approximately the same time of day (~4PM). Speaking anecdotally, this is the time of day at which I seem to have my best training sessions. This would obviously be influenced by how early in the day you arise, though. If you’re up earlier, this time would likely be shifted forward a bit.
|
I guess I'll try to wake up a little earlier (ugh!) and spend a little more time warming up before doing any heavy compound movements.
My question (there's always another question with me isn't there?) is whether these studies took into account how doing a warmup protocol effected ROM, spinal length, risk, etc. I'm betting they didn't. Which goes more to OldGuy's point, that a proper warm up should help to minimize any risk.