# The Relationship between Training Load Measures and Next-Day Well-Being in Rugby Union Players
## 2 Materials and Methods
### Training Load  
TL was calculated using different methods based on HR, sRPE and Microelectrittromechanical systems (MEMS) (GPS 10 Hz, Tri-axial accelerometer 100 Hz; Catapult S5, firmware 6.75, Catapult Innovations, Melbourne, Australia). They were measured for each player in every training session and competitive match for six weeks during the regular season, from November to December. HR was measured using a short-range telemetry HR transmitter strap recording at 1 s intervals (Polar Team 2 System, Polar Electro Oy). Raw HR data for each training session and match were exported into dedicated software to determine individual session individualised Training Impulse (iTRIMP), [PERSON]'s TRIMP (bTRIMP), [PERSON]'s TRIMP (luTRIMP) and [PERSON]'s TRIMP (eTRIMP) [19]. Calculation of bTRIMP were based on training duration, HR, and a weighting factor using the following formula where; \(\Delta\)HR = (HR\({}_{\text{ex}}\) - HR\({}_{\text{rest}}\))/(HR\({}_{\text{max}}\) - HR\({}_{\text{rest}}\)), \(\mathcal{E}\) equals the base of the Napierian logarithms, 1.92 equals a generic constant for males and \(x\) equals \(\Delta\)HR:  
\[\text{bTRIMP}=\text{duration training}\text{ (minutes)}\times\Delta\text{HR} \times 0.64\text{e}^{1.92\text{x}}\]  
[PERSON] TRIMP [19] was calculated based on time spent in five HR zones and multiplied by a zone specific weighting factor: duration in zone 1 (50-59% of HR\({}_{\text{max}}\)) multiplied by 1, duration in zone 2 (60-69% HR\({}_{\text{max}}\)) multiplied by 2, duration in zone 3 (70-79% HR\({}_{\text{max}}\)) multiplied by 3, duration in zone 4 (80-89% HR\({}_{\text{max}}\)) multiplied by 4 and duration in zone 5 (90-100% HR\({}_{\text{max}}\)) multiplied by 5. An adapted version of luTRIMP was calculated by multiplying time spent in three HR zones based around HR at LT and OBLA; where duration in zone 1 (\(\leq\)HR at LT) is multiplied by weighing factor 1, duration in zone 2 (\(>\)HR at LT and \(<\)HR at OBLA) multiplied by 2 and duration in zone 3 (\(\geq\)HR at OBLA) multiplied by weighting factor 3. The iTRIMP was calculated as per the method previously described by [PERSON] et al. [3; 18] and [PERSON] et al. [9]. Approximately 30 min after each training session and match, players reported their RPE using the method of [20]. Each player was asked how hard they found each training session or match, reporting their subjective perception of effort using the Borg 10-point category-ratio scale. Players' sRPE was subsequently calculated as the RPE multiplied by the duration of the training session or match. Players were familiarised with the use of the RPE scale for a three-week period prior to the start of the six-week study period.  
External training load was measured with a MEMS device. The reliability of MEMS devices has previously been demonstrated for the measurement of speed and distance in team sports [21; 22]. MEMS devices were switched on at least ten minutes prior to each training session and match to ensure a full satellite signal. Players were fitted with the same HR and MEMS device for each session. The MEMS device was placed in a pouch positioned between the players' scapulae. After every training session, the recorded data were downloaded onto a laptop using the manufacturer's software (Sprint 5.1, Catapult Innovations). External load measures were determined from MEMS activity data. Activity was examined for total distance (TD) and distance covered at high-speed. Arbitrary predetermined high-speed distance thresholds were set at \(\geq\)15 km\(\cdot\)h\({}^{-1}\) (HSD) and \(\geq\)18 km\(\cdot\)h\({}^{-1}\) (VHSD) in accordance with previous studies [21; 22]. Additionally, each player's vOBLA (vOBLA ranged from 8.7 to 13.1 km\(\cdot\)h\({}^{-1}\)) was employed to set an individualised high-speed distance threshold (iHSD).