Heart Rate

During the intervention, a chest belt (Polar H7) and heart rate receiver (Polar M 430) continuously measured heart rate (beats/min). The maximum heart rate was selected for further analyses.

### Mechanical Pain Threshold

Before and directly after each intervention, the mechanical pain threshold (N/cm2) was determined. Participants reclined supine on a bench with their legs extended. With an algometer (FPK, Wagner Instruments, Greenwich, CT, USA) pressure was applied on the skin (1 cm2). Three measurements were taken in the middle of both mm. recti femoris. The average of the three measurements was selected for further analyses.

### Blood Sampling and Plasma Preparation for miRNA Profiling

In order to minimize pre-analytical variables that might influence the miRNA expression profile, care was taken in the collection of blood and the preparation of plasma to prevent blood cell contamination and hemolysis. Before and after each intervention, fingertip capillary blood samples (≥200 μL) were collected in microvettes (system for capillary blood collection) containing Ethylenediaminetetraacetic acid (EDTA). Blood samples were centrifuged for 10 min at 3000 rpm and 4 ◦C. After the first centrifugation step, the upper plasma phase was transferred to a new tube without disturbing the intermediate buffy coat layer. The plasma samples were centrifuged a second time for 10 min at 15,000 rpm and 4 ◦C. The cleared supernatant was carefully transferred to a new tube and frozen at −80 ◦C.

### Determination of Hemolysis

To assess hemolysis, oxyhemoglobin absorbance was measured at 414 nm in plasma samples using NanoDrop (peqlab Biotechnologie GmbH; Erlangen, Germany).
