ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effects of Zingiber cassumunar (Plai cream) in either 7% or 14% concentration on delayed onset muscle soreness (DOMS).</p><p><b>METHODS</b>Seventy-five untrained healthy volunteers (28 males and 47 females), performed 4 sets of 25 eccentric repetitions of the dominant quadriceps muscle on an isokinetic dynamometry machine. Participants were then randomized into 3 groups: 14% Plai cream, 7% Plai cream and placebo cream. Two grams of the cream (strips of 5-cm long) were gently rubbed into the quadriceps muscles for 5 min immediately following the exercise and every 8 h thereafter for 7 d in all groups. Muscle soreness, muscle strength, jump height, thigh circumference and creatine kinase were measured before and after eccentric exercise.</p><p><b>RESULTS</b>Compared to the placebo cream the 14% Plai cream substantially reduced muscle soreness over the 7 d by -82% (95% CI = -155% to -6%, P = 0.03), but had similar muscle soreness effects to 7% Plai cream (-34%, -96% to 27%, P = 0.2). Compared to the placebo cream the 7% Plai cream resulted in a small non-significant reduction in muscle soreness levels over the following 7 d (-40%, -116% to 36%, P = 0.3). Compared to placebo cream there was little effect of Plai cream (7% or 14%) on muscle strength, jump height, thigh circumference or creatine kinase concentration.</p><p><b>CONCLUSION</b>Using 14% Plai cream over a 7-day period substantially reduced muscle soreness symptoms compared to 7% Plai cream or a placebo cream. The authors suggest that the administration of 14% Plai cream is a useful alternative in the management of DOMS.</p><p><b>TRIAL REGISTRATION</b>Thai Clinical Trial Registry TCTR20140215001.</p>