Impact of a low-intensity exercise prior to infrared thermography measurements on skin temperature under conditions of muscle soreness

The aim of this study was to determine whether a low-intensity exercise may influence outcomes of skin temperature measured by infrared thermography (IRT) in the presence or not of delayed-onset muscle soreness (DOMS). Seventeen participants were recruited (12 men, age 24 ± 6 years, body mass 72.6 ± 12.5 kg, and height 1.8 ± 0.1 m). They visited the laboratory on two days with 48 h in between. On day 1, participants performed a 10-minute low-intensity treadmill walk followed by a squat protocol to induce DOMS (10 sets of 10 repetitions at 70% of body mass). On day 2, when participants reported DOMS, they returned to the laboratory and completed another 10-minute low-intensity treadmill walk. On each day, quadriceps DOMS was assessed using a numerical pain rating scale, and skin temperature was measured using IRT on both days. The skin temperature was higher before (p = 0.01; d=-0.44) and after walking (p = 0.03; d=-0.39) on the second day when significant DOMS was reported by the participants. However, skin temperature was not altered by light walking prior to the measurements on day 2. In conclusion, low-intensity walking did not induce detectable changes in skin temperature in the quadriceps before or after DOMS, suggesting that that acute, low-intensity exercise is unlikely to be a relevant confounder or enhancer of IRT-based assessment of DOMS.