Changes

[[File:Length Tension Curve and DOMS.jpg|right|thumb|500px|A chart of a subject before and 7 days after DOMS inducing hamstring exercise. The chart shows the angle and the torque developed, indicating that after training the hamstrings are not only stronger, but are able to generate power at significantly longer length. This may be part of the underlying mechanism for the repeated bout effect.]]The DOMS that follows an initial bout of eccentric exercise is much less on subsequent similar bouts. This is often called the Repeated Bout Effect (RBE)<ref name="Howatson-2008"/><ref name="Cheung-2003"/>. The initial bout does not have to cause significant soreness or damage<ref name="Clarkson-1987"/>. As few as 2-10 maximal eccentric repetitions can protect against a subsequent larger bout (24-50), but the initial bout must be close to maximal effort<ref name="Brown-1997"/>. By contrast, eight weeks of training with 50% of the maximal eccentric load did not provide protection against a subsequent maximal bout<ref name="Nosaka-2002"/>. There is some cross-over of protection between different forms of exercise. For instance, eccentric weight training protects against soreness and weakness in subsequent downhill running<ref name="Eston-1996"/>. The protection from the RBE is long lived. One study showed that while the initial weakness was not reduced by the RBE, the recovery of strength was much faster for up to 9 months, and soreness was less for up to 6 months<ref name="Nosaka-2001"/>. Another study showed that 30 minutes of downhill running provides protection for between 6 and 9 weeks<ref name="Byrnes-1985"/>. There is evidence that the RBE may rapidly start to provide protection from soreness and weakness<ref name="Mair-1995"/>, within 5 days<ref name="Ebbeling-1989"/>, and possibly within 24 hours<ref name="Chen-2001"/>. One study<ref name="Brockett-2001"/> demonstrated a change in the length-tension curve of DOMS trained muscles. As shown on the chart to the right, 7 days after a bout of DOMS inducing exercise, the hamstring is able to generate more force and generate it at a greater angle.