Table 2.

Summary of measure and measurements in the included articles.

Construct	Measure	Measurement	Thresholds and/or Metric Formula	Reference	Further Reading
Internal Load	Heart Rate	% HRmax	Zone 1: ≤75% HRmax; zone 2: 75–84.9% HRmax; zone 3: 85–89.9% HRmax; zone 4: ≥90% HRmax.	[47,48]	[49]
			Zone 1: ≤75% HRmax; zone 2: 75–84.9% HRmax; zone 3: 85–89.9% HRmax; zone 4: ≥90% HRmax.	[50]	[51]
			Zone 1: 50–60% HRmax; zone 2: 60–70% HRmax; zone 3: 70–80% HRmax; zone 4: 80–90% HRmax; zone 5: 90–100% HRmax.	[52,53,54,55,56,57,58,59,60,61]	[62,63,64]
		LTzone	zone 1: <LT; zone 2: between LT and AT; zone 3: >AT (k = 1 for zone 1; k = 2 for zone 2, and k = 3 for zone 3)	[52,54]	[63]
		Bannister TRIMP	D × (∆HRratio) × (0.64 × e b × HRB) (D = (∆HRratio) [(HRTS– HRB)/(HRmax– HRB)]) weighting factor (k) = 1.62 (females);1.92 (males)	[50,52,54,57,58]	[63]
		Edward’s TL	D (zone 1) × 1+ D (zone 2) × 2 + D (zone 3) × 3+ D (zone 4) × 4 + D (zone 5) × 5	[52,54,57,65]	[66]
		Lucia’s TL/LTzone TL	D (zone 1) × 1+ D (zone 2) × 2 + D (zone 3) × 3	[52,54]	[66,67]
		Stagno TL/TRIMPMOD	[(HRTS − HRB)/(HRmax − HRB)]) weighting factor = 0.1225e3.9434x	[50]	[51]
		HR-TL	∑ (time (min) spent in zone × numerical factor of zone)	[56]	[68]
	Perceived Exertion	sRPE	RPE × D	[52,54,55,56,57,58,59,69,70,71,72]	[64,73,74,75]
		sRPEresp TL/sRPEmusc TL	sRPE × D	[71]	[76,77]
		Fatigue score	Seven-point scale: training exertion, sleep quality, muscle soreness, infection/illness, concentration, training efficiency, anxiety/irritability, and general stress.	[69]	[78]
		HI	Fatigue, stress muscle soreness, and quality sleep.	[72]	[79]
External load	Distance and speed	Speed zones/ thresholds	Zone 1: 0–6.9 km× h−1; zone 2: 7.0–9.9 km × h−1; zone 3: 10.0–12.9 km × h−1; zone 4: 13–15.9 km × h−1; zone 5: 16–17.9 km × h−1; and zone 6: ≥18.0 km × h−1 (sprints).	[47,48]	[80,81]
			Walking/jogging: <10.8 km × h−1; HSR: ≥20.9 km × h−1; SPR: >24.1 km × h−1.	[53,82,83]	[32,40,84,85,86]
			Standing: 0–0.6 km × h−1; walking: 0.7–7.1 km × h−1; jogging: 7.2–14.3 km × h−1; running: 14.4–19.7 km × h−1; HSR: 19.8–25.1 km × h−1; SPR: >25.1 km × h−1.	[87,88,89,90,91]	[92,93]
			Running: 11.4–18.9 km × h−1; HSR: 15.0–18.9 km × h−1; SPR: >19.0 km × h−1.	[58]	[94]
			Walking: 0–6.9 km × h−1; jogging: 7.0–13.9 km × h−1; Running: 14.0–20.0 km × h−1; SPR: >20.0 km × h−1.	[88,89,95]	[96]
			Low-speed running: <14.4 km × h−1; HSR: >19.8; SPR: >25.2 km × h−1.	[57,70,91,97,98,99]	[11,100,101,102,103,104]
			Low-speed running: <14 km × h−1; HSR: 14.4 km × h−1; HSR: 19.8–25.2 km × h−1	[102,105]	[104]
			HSR: >19 km × h−1.	[72]	[104]
			HSR: >16 km × h−1.	[61]	[85]
			Standing/walking: 0–7.2 km × h−1; low intensity running: 7.3–14.3 km × h−1; moderate intensity running: 14.4–21.5 km × h−1; HSR: 19.8–25.1 km × h−1; very HSR > 25.1 km × h−1.	[106,107,108]	[30,40,109]
	Acceleration	Acceleration zones/ thresholds	Low: 1–2 m × s−2; Moderate: 2–3 m × s−2; High: >3 m × s−2.	[53]	[85]
			ACC: >2.5 m × s−2; DEC: <2.5 m × s−2.	[91]	[40]
			ACC: >2 m × s−2.	[99,110]	[111]
			ACC/DEC: >3 m × s−2.	[61,82,98]	[86]
			ACC: >4 m × s−2.	[108]	[100]
			ACC: medium (1.5–3.0 m × s−2); high (>3.0 m × s−2). DEC: medium (−1.5 to −3.0 m × s−2); high (<−3.0 m × s−2).	[82]	[102,111]
	Accelerometry	Body impacts/body load	Zone 1: 5.0–6.0 g; zone 2: 6.1–6.5 g; zone 3: 6.5–7.0 g; zone 4: 7.1–8.0 g; zone 5: 8.1–10.0 g; zone 6: ≥10.1 g.	[47,48,98,99]	[112,113,114]
		Player load	$\sqrt{{(a_{x1} - a_{y-1})}^2+(a_{y1} - a_{y-1}{)}^2+{(a_{z1} - a_{z-1})}^2 }/100$	[53,88,89,115]	[10,116]
		Player load	${(a_{x1} - a_{y-1})}^2+(a_{y1} - a_{y-1}{)}^2+{(a_{z1} - a_{z-1})}^2$	[57]	[117]
		Dynamic-stress load	∑ (body load for each zone × body mass)	[118]	[119]
Ratios/ scores	Ratio/scores (Weekly TL)	Work: rest ratio	High to very high: >16 km × h−1; moderate: 10.0–15.9 km × h−1; low intensity: 7.0–9.9 km × h−1; very low intensities: 0–6.9 km × h−1 (normalized for each 100 m).	[47]	[80]
		Work: rest ratio	WRR: distance covered at a speed ≥ 4 km × h−1 period of activity or work divided by the distance covered at a speed <3.9 km × h−1; period of recovery or rest); FEHS ≥ 18 km × h−1; FESS ≥ 21 km × h−1.	[115]	[119]
		THIA (%)	∑ (MSR, HSR and SPR)	[107]	originally proposed by Rago et al. [107]
	Ratio/scores (Weekly TL and ML)	TMr	(Weekly load)/(Match load)	[95]	originally proposed by Clemente et al. [95]
		Session volume score	$\left({\mathrm{Volume} \mathrm{Metric} \mathrm{x}}_1,{\mathrm{x}}_2,{\mathrm{x}}_3,{\mathrm{x}}_4 \mathrm{of} \mathrm{MD} (\%)/4\right)$	[97]	originally proposed by Owen et al. [97]
		Session intensity score	$\left({\mathrm{Intensity} \mathrm{Metric} \mathrm{x}}_1,{\mathrm{x}}_2,{\mathrm{x}}_3,{\mathrm{x}}_4\mathrm{of} \mathrm{MD} (\%)/4\right)$	[97]	originally proposed by Owen et al. [97]
Energy cost and metabolic power	Equivalent- estimation	EC	EC = 155.4 × 155.4 × ES4 × 155.4 × ES3 × 155.4 × ES2 × 155.4 × ES × EM × KT	[90]	[84,85]
		Pmet	HP: 20–35 W× kg−1; EP: 35–55 W × kg−1;: >55 W × kg.	[82,83,118]	[84,85]

∆HR—HR variation; ACC—acceleration; AT—anaerobic threshold; D—duration; DEC—deceleration; EC—energy cost; EM—equivalent body mass; EP—elevated power; ES—equivalent slope; FEHS—frequency of efforts at high speed (≥18 km × h⁻¹); FESS—frequency of efforts at sprint speed (≥21 km × h⁻¹); HI—Hooper Index; HP—high power; HR—heart rate; HR_B—basal heart rate; HR_max—maximum heart rate; HR_TL—heart rate training load; HR_TS—average training session heart rate; HSR—high speed running; K—coefficient relative; KT—constant; LT_zone—lactate threshold; LT_zone lactate threshold zone; MD—match day; ML—match load; MS—maximum power; P_met—equivalent metabolic power; RPE—ratings of perceived exertion; SPR—sprinting; sRPE—sessions ratings of perceived exertion; sRPEmusc-TL—sessions ratings of muscular training load; sRPEres-TL—sessions ratings of respiratory training load; THIA—total high-intensity activity; TL—training load; TMr—training/match ratio; TRIMP—training impulse; TRIMP_MOD—modified training impulse; WRR—work:rest ratio.