The necessary rest time interval between exercise bouts is not fully understood. We know that delayed onset muscle soreness peaks between 24-48 hours after exercise and can take up to 7 days to dissipate, however it’s not necessary to wait 7 days to workout again.
The soreness is likely caused by multiple factors associated with muscled damage including swelling, the release of noxious chemicals in the muscle cells, the stimulation of pain receptors and other by products of local inflammation.
For those of you who were wondering…’lactic acid’ has nothing to do with it <– this is just gym talk for those people who don’t understand exercise physiology.
The muscle damage and soreness we feel from time to time after our workouts seems to be more closely linked to the eccentric phase of each rep (the negative phase) rather than the concentric (the push or up phase)
Even if you don’t purposefully do ‘eccentric’ exercises most heavy weights require a controlled eccentric contraction as well (ex: when lifting in the 5-8 rep ranges)
It is possible to train through soreness however there is likely a limit to how sore you can be and still get a good workout in.(there doesn’t seem to be any danger training while sore, but you just might not be able to generate enough force to make the workout worthwhile)
A good rule of thumb might be: Train through mild to moderate soreness, but hold off through the worst soreness until it dissipates to a more manageable level.
On a scale of 1-10 that might mean it’s ok to train through soreness levels of 1-6, but back off if your soreness level is a 7 or higher.