Objective To determine whether six weeks' of acupuncture has a positive effect on plantar flexion muscle strength and whether electroacupuncture (EA) has a greater effect than manual acupuncture (MA) on plantar flexion, so that the most beneficial method of acupuncture can be established for strengthening muscles. Methods A randomized controlled trial with parallel groups. A total of 20 participants were randomly assigned to three groups: a control/non-acupuncture group (n=6), a manual acupuncture group (MAG) (n=8) and an electroacupuncture group (EAG) (n=6). MAG and EAG received three 25-minute treatments per week for 6 weeks. The control group continued with their normal training activity and received no treatment. The maximal voluntary contraction (MVC) of the ankle plantar-flexors at 30° per second was measured using Biodex system 3. Results Both MA and EA had a positive effect in increasing plantar flexion strength. The likelihood for this happening was high; 69% for MA and 92% for EA when compared with the control group. However the effect size was small for both groups. There was only a trivial difference in the effect size between the EAG and the MAG in regards to average plantar flexion torque. Conclusion EA and MA have a beneficial effect on plantar flexion muscle strength compared with the control group in healthy population.