Delayed onset muscle soreness, otherwise known as DOMS, is simply a fact of life. The older you get, the more you know this to be true. No longer can you run around the field playing a game of tag football without feeling it the next day. The same goes for a tough workout. The soreness you feel 24-72 hours after intense or novel exercise is just part and parcel. DOMS can be particularly noticeable if your workout included eccentric exercises (where you lengthen a muscle while keeping it contracted, such as the downward part of a bicep curl).
The exact physiological mechanism that causes DOMS still evades scientists, but they believe it’s due to ‘microtrauma’ done to the muscles at the cellular level. Cell contents are leaked in the surrounding tissues causing a natural inflammation response. Somewhere in the process your muscles are built up stronger and more prepared than they were before.
Conventional wisdom holds that by warming up you cause the bundles of muscle cells (myofibrils) to move more easily and thus suffer less damage during exercise than they would without the warm-up. It also holds that by cooling down after a workout, it will somehow interrupt the cascade triggered by the microtrauma to the myofibrils, thus stopping or reducing the subsequent inflammation.
Now of course, onto the research. When it comes to eliminating soreness and preventing injury, warming up and cooling down have failed to make the cut. Numerous studies have been performed recently, and the vast majority of them show no benefit whatsoever to either warm-ups or cool-downs. It should be noted that one or two studies have found that warming up (not cooling down) has offered a slight benefit with a very minor reduction in pain, though this has not been replicated across the board by other studies.
Perhaps the most damning report came from the Cochrane review in 2007 that reviewed 10 of the largest studies ever performed on warmups and found that there was ‘minimal or no effect’ on muscle soreness experienced by individuals who performed a warmup when compared to individuals who did not.
Long story short, warm-ups and cool-downs are practises that are absolutely not mandatory or necessary when working out. If you do these things and enjoy them, then by all means continue – it won’t hurt you. However, if you feel stretched for time already and don’t have any interest in adding these to your workout routine then you can rest assured that you’re not doing yourself any damage.