Table 2.

Included Studies, Training Parameters, and Incidence of Injuries Continued on Next Page

Authors	Study Design	Follow-Up	Sample Size (% Females)	Type of Runners	Mean Age ± SD, y	Age Range	Running Program	Reported RRI Incidence	Association Between RRIs and Training Parameters	Recent Changes in Training Parameters
Becker et al40	Prospective	24 mo	n = 24 (37.5%)	Competitive	19 ± 1.2		Usual training routine of the team	75.0% of runners (18/24) reported RRIs	Running distance: No difference in weekly volume between injured (52 ± 21.8 km) and uninjured (54 ± 24.1 km; P = .684) runners
Begizew et al37	Prospective	10 mo	n = 229 (52.8%)	Competitive	Not available	17–26 y: n = 205; >26 y: n = 24	Self-selected running program	62.4% (143/229); 3.54 RRIs/1000 h of running	Running distance: 40–50 km/wk = 99.7% ↓ risk of RRI than 60–70 km/wk (OR = 0.003, 95% CI = 0.000, 0.073; P ≤ .0001) 50–60 km/wk = 94.7% ↓ risk of RRI than 60–70 km/wk (OR = 0.053, 95% CI = 0.004, 0.728; P ≤ .028)
Bovens et al16	Prospective	18 mo	n = 73 (13%)	Novice	Males = 35.2 ± 7.9; females = 33.5 ± 6.4		Training program with 3 phases, each finishing with race (15, 25, and 42 km) Phase 1 = 28 wk (mean/wk = 2.7 h, 3.8 trainings, 24.1 km) Phase 2 = 23 wk (mean/wk = 3.2 h, 3.6 trainings, 34.9 km) Phase 3 = 30 wk (mean/wk = 4.0 h, 3.5 trainings, 43.6 km)	84.9% (62/73); RRI incidence in phase 1 = 58%, phase 2 = 60%, phase 3 = 67%	Running distance: ↑ Distance related to more injuries during phases 1 (r2 = 0.36, P = .001) and 3 (r2 = 0.16, P = .015) Running duration and frequency: No analyses reported	Recent changes: Significant ↑ injury rates during phases 1–2 and 1–3. Training amount during last phase of marathon preparation ↑ injury risk (from mean distance/wk = 34.9 km to 43.6 km and mean duration = 3.2 h/wk to 4.0 h/wk)
Buist et al18	RCT	8 or 13 wk	n = 532 (57.5%)	Novice	39.8 ± 10.1		GTG = <10% volume progression/wk (13 wk) STG = >10% volume progression/wk (8 wk)	GTG: 20.8% (52/250) STG: 20.3% (48/236)		Recent changes: No effect of graded “10% rule” on RRIs, compared with standard training program (P = .90)
Buist et al4	Prospective	8 wk	n = 629 (67.1%)	Novice, recreational	43.7 ± 9.5		8-wk training program	25.9% (163/629); 30.1 RRIs/1000 h of running	Running duration: Not associated with RRIs (P > .38)	Recent changes: Week-to-week changes in running frequency or duration were not associated with RRIs (P > .075)
Buist et al17	Prospective	8 or 13 wk	n = 532; 486 followed running program (57.5%)	Novice	39.8 ± 10.1		GTG = <10% volume progression/wk (13 wk) STG = >10% volume progression/wk (8 wk)	20.6% (100/486); 33.0 RRIs/1000 h of running	Running duration: Not associated with RRIs
Dallinga et al23	Prospective	3 mo	n = 706 (46.9%)	Recreational	43.9 ± 11.6		Usual training routine in preparation for 8- or 16-km run	20.1% (142/706) in preparation for or during event	Running distance and duration: Not associated with RRIs Duration: OR = 1.00, 95% CI = 0.999, 1.002; Distance: OR = 1.24, 95% CI = 0.65, 2.38
Damsted et al45	Prospective	14 wk	n = 508 (62.2%)	All abilities	37	29–46 y	1) Distance-based schedule 2) Pace-based schedule 3) Mixed schedule 4) Self-chosen running program (not analyzed)	26.8% (136/508) across all running schedules: 24.2% (40/165), distance-based running schedule; 19.4% (14/72), pace-based running schedule; 30.3% (82/271), mixed running schedule	Running distance and intensity: Tendency (nonsignificant) for fewer injuries among runners with running distance >15 km/wk (RD = −11.3%, 95% CI = −27.2, 4.6), high pace (RD = −17.4%, 95% CI = −39.0%, 4.5%), or combination (RD = −8.1%, 95% CI = −22.3%, 6.1%)
Damsted et al44	Prospective	14 wk	n = 261 (60.2%)	All abilities	36	27–45 y	1) Distance-based schedule 2) Pace-based schedule	21.5% (56/261): 24.2% (40/165) distance-based running schedule; 16.7% (16/96) pace-based running schedule		Recent changes: More runners injured when weekly running distance ↑ 20%–60% compared with ↑ ≤20% (only at 21 d, not at 56 or 91 d): RD21 days = 22.6%, 95% CI = 0.9%, 44.3%; RD56 days = 19.0%, 95% CI = −11.9%, 50.0%; RD98 days = 4.2%, 95% CI = −26.2%, 34.7% No difference between runners ↑ distance >60%: RD21 days = 5.8%, 95% CI = −8.4%, 20.1%; RD56 days = 7.8%, 95% CI = −14.0%, 29.6%; RD98 days = −4.3%, 95% CI = −27.9%, 19.3%
Dijkhuis et al38	Prospective	24 mo	n = 23 (30.4%)	Competitive	22.5 ± 5.7		Individualized program designed by running coach	91.3% (21/23)	Running duration and intensity: No associations between acute workload, chronic workload, and risk of RRI (P > .05)	Recent changes: No associations between weekly acute:chronic workload ratio and RRI risk: wk 1–2, P > .451; wk 2–3, P > .494, except for “low increase'' (P = .013); wk 3–4, P > .125
Fields et al24	Prospective	12 mo	n = 40 (22.5%)	Recreational	37	20–40 y (n = 25); 41–60 y (n = 15)	Self-selected running program	42.5% (17/40)	Running distance: No significant association with RRIs, despite RRIs in 80% of those running <32.2 km/wk vs 50% of those running >64.4 km/wk
Fokkema et al46	Prospective	3 mo	n = 997 (35.0%)	All abilities	42.2 ± 11.7		Online running program for half-marathon or a marathon	51.3% (511/997)	Running distance, duration, and intensity: No associations with RRI risk Weekly distance (vs 20–32 km): <20 km: OR = 1.41, 95% CI = 0.86, 2.32; >32 km: OR = 0.97, 95% CI = 0.63, 1.50 Longest-run duration (vs 15–21 km): <15 km: OR = 1.19, 95% CI = 0.69, 2.04; >21 km: OR = 0.83, 95% CI = 0.52, 1.30 Intensity (vs 5.25–6.00 min/km): <5.25 min/km: OR = 0.68, 95% CI = 0.41, 1.11; >6.00 min/km: OR = 1.23, 95% CI = 0.77, 1.98
Hamstra-Wright et al41	Prospective	18 wk	n = 113 (74.3%)	All abilities		20–70 y	18-wk marathon training program	24.8% (28/113)	Running intensity: 96.4% (27/28) of runners injured in first 6 wk were doing tempo or interval runs 56.9% (37/65) of runners not injured during first 6 wk were doing tempo or interval runs; similar mileage as injured runners Tempo runs during first 6 wk ↑ RRI odds (OR = 3.96, 95% CI = 1.35, 11.61). Interval runs during first 6 wk tended to ↑ RRI odds (not significant; P = .06)
Hayes et al39	Prospective	3 mo	n = 97 (58.8%)	Competitive	Males = 19.0 ± 0.2, females = 19.2 ± 0.2		Cross-country season training program from university coach	52.6% (51/97)		Recent changes: Athletes with larger differences in running volume between regular and high-mileage weeks more likely to be injured but results not significant (P = .06)
Hespanhol Junior et al26	Prospective	12 wk	n = 200 (26%)	Recreational	42.8 ± 10.5		Self-selected running program	31.4% (60/191): 10 RRIs per 1000 h of running	Running duration: ↑ Duration of training session associated with ↑ RRI risk (OR = 1.01, 95% CI = 1.00, 1.02) Running intensity: Inconclusive results; speed training associated with ↑ RRI risk (OR = 1.46, 95% CI = 1.02, 2.10) but interval training associated with ↓ RRI risk (OR = 0.61, 95% CI = 0.43, 0.88).
Hespanhol Junior et al25	Prospective	12 wk	n = 89 (23.6%)	Recreational	44.2 ± 10.6		Self-selected running program	27.0% (24/89): 7.7 RRIs per 1000 h of running	Running distance, duration, frequency, intensity: No associations with RRI risk Distance: P = .51; Duration: P = .25; Frequency: P = .65; Intensity: P = .68
Hootman et al47	Prospective	1–5 y	n = 3090 (19.7%)	Novice, Experienced		20–85 y	Run/walk/jog program, 1–5 y	39.1% (1207/3090) during 5-y recall period, 17.4% (481/2762) during 1-y recall period	Running distance: ↑ Run/walk/jog distance (>32.2 km/wk) associated with greater RRI risk during 5-y recall period; men's HR = 1.66, 95% CI = 1.43, 1.94; women's HR = 2.08, 95% CI = 1.45, 2.98; no association during 1-y recall period Running frequency: No associations with RRI risk during 5-y or 1-y recall periods Running intensity: No associations with RRI risk during 5-y recall period During 1-y recall period, ↓ intensity (15+ min/mile) associated with ↓ RRI risk only in men (OR = 0.51, 95% CI = 0.35, 0.74).
Jakobsen et al27	Prospective	12 mo	n = 41 (9.8%)	Recreational	41.9		Study group: endurance, hill and speed training, education; control group: no details provided	85.7% (18/21) in study group, 65.0% (13/20) in control group RRIs/1000 h of running: study group = 7.4 during training, 30.7 during races; control group = 6.9 during training, 62.5 during races When adjusted for training time, RRI incidence similar in both groups	Running distance: ↑ RRIs in study group (P < .001), who ran more weekly distance at same pace Mean running distance (km/wk): Study group: 43.0, 95% CI = 41.6, 44.4 Control group: 33.4, 95% CI = 32.0, 34.9
Kemler et al48	Prospective	3 mo	n = 4621 (41.8%)	Novice, Experienced	34.2		Usual training routine	8.8% (405/4621) within 3-mo recall period: 9.5% (134/1405) of novice runners, 8.4% (271/3216) of experienced runners	Running duration: No association with injury incidence: novice mean = 14.6 h (IQR = 32.5) vs experienced mean = 30.0 h (IQR = 67.5) for similar injury rates
Kluitenberg et al19	Prospective	6 wk	n = 1696 (78.5%)	Novice	43.3 ± 10.0		6-wk “Start to Run” program	10.9% (159/1696)	Running duration: Running <60 min in previous 7 d protected against RRI (multivariate analysis: HR = 0.41, 95% CI = 0.20, 0.86) Running frequency: Not significantly associated with RRI but trend that running 3×/wk was more hazardous than 2×/wk (HR = 1.42, 95% CI = 0.97, 2.08). Running intensity: ↑ Intensity associated with RRI (multivariate analyses: HR = 1.28, 95% CI = 1.18, 1.40).
Lehmann et al50	Prospective	4 wk, 2 y in row	n = 17 (Unknown)	Experienced distance runners	33.5		Year 1: 103% ↑ in running volume (ITV; n = 8) Year 2: 152% ↑ in running intensity (ITI; n = 9; 7 had participated in year 1)	Only minor injuries that did not alter planned training; no details on number or type of injuries	Running distance: ITV: Average distance ↑ from 85.9 km to 174.6 km (week-to-week ↑ of 33.9%, 32.6%, and 36.8%, respectively); no more injuries than ITI, which ↑ from 61.7 km to 84.7 km (week-to-week ↑ of 1.9%, 20.0%, and 12.2%, respectively). Running intensity: ITI: Tempo pace and interval runs ↑ week-to-week from 14.7% of total training (9.0 km) to 23.7% (14.9 km), 24.6% (18.6 km), and 26.8% (22.9 km), respectively; no more injuries than ITV, which changed from 7.3% of total training (6.3 km) to 4.0% (4.6 km), 3.8% (5.4 km), and 2.0% (3.5 km), respectively	Recent changes: No change in RRI risk based on distance and intensity changes
Lun et al28	Prospective	6 mo	n = 87 (49.4%)	Recreational	38		Usual training routine	79.3% (69/87); RRI incidence/1000 h of running = 59%	Running distance: No difference in RRI incidence between uninjured (30.3 km) and injured (34.2 km) runners Running frequency: No difference between uninjured (3.8/wk) and injured (3.7/wk) runners
Lysholm et al36	Prospective	12 mo	n = 41; Sprinters excluded (9.8%)	Competitive	Middle-distance runners = 18.6 ± 2.4; long-distance runners = 34.5 ± 7.4		Training with their athletic clubs	76.9% (10/13) of middle-distance runners, 5.6 RRIs/1000 h; 57.1% (16/28) of long-distance runners, 2.5 RRIs/1000 h	Running distance: Significant correlation in long-distance runners between ↑ distance covered during given month and No. of injury days the next month (r = 0.59)
Malisoux et al34	Prospective	22 wk	n = 264 (26.1%)	Recreational	Single shoe (n = 116) = 40.5 ± 9.8; multiple shoes (n = 148) = 44.2 ± 8.8		Usual training routine (at least 1x/wk)	33.1% (87/264); 7.64 RRIs/1000 h of running	Running duration: ↑ Session duration associated with ↓ RRI risk in unadjusted model (HR = 0.963, P < .001) Running frequency: ↑ Frequency associated with ↓ RRI risk in unadjusted model (HR = 0.707, P = .002) Running intensity: ↑ Intensity not associated with RRI risk (HR = 0.873, P = .248)
Messier et al29	Prospective	24 mo	n = 300 (42.7%)	Recreational	Injured = 42.3 ± 9.7, uninjured = 40.0 ± 10.3		Self-selected running program	66.3% (199/300); 55.8% of injured runners (111/199) were injured >1x during 24-mo observation period	Running distance: No association with RRI risk (P = .16) Running intensity: No association with RRI risk (OR = 1.058; 95% CI = 0.727, 1.540; P = .20)
Nielsen et al20	Prospective	10 wk	n = 58 (48.3%)	Novice	39.8 ± 9.2		Not reported	22.4% (13/58)	Running distance: No association with RRI risk (P = .23)	Recent changes: Not statistically significant (P = .07) but injured runners ↑ average weekly running distance by 31.6% ± 3.1%, compared with 22.1% ± 2.1% in uninjured runners Injured runners had higher weekly progression in running distance week before injury onset compared with other weeks (86% difference, 95% CI = 12.9%, 159.9%; P = .026).
Nielsen et al21	Prospective	12 mo	n = 873 (49.5%)	Novice	37.2 ± 10.2		Self-selected running program	23.1% (202/873)		Recent changes: No difference in RRI risk between different progressions in weekly distance (rolling average calculated after each running session, not cumulative average change in volume) <10%: HR = 1.00 (reference) 10%–30%: HR = 0.99, 95% CI = 0.55, 1.82 >30%: HR = 1.17, 95% CI = 0.84, 1.63 Those progressing >30% were more vulnerable to distance-related injuries compared with <10% (HR = 1.59, 95% CI = 0.96, 2.66; P = .07).
Pollock et al22	RCT	20 wk	Cohort 1: n = 87; 18 controls (0%)	Novice	N/A		Cohort 1, duration study: 3 d/wk for 15, 30, or 45 min; total = 20 wk	26.0% (33/127) 33.3% (23/69); RRI reported in 20.0% (4/20), 24.0% (6/25), and 54.2% (13/24) of 15-, 30-, and 45-min groups, respectively	Running duration: ↑ Running duration (45 min/session) associated with ↑ RRI risk
			Cohort 2: n = 71; 13 controls (0%)	Novice	N/A		Cohort 2, frequency study: 30-min runs 1, 3, or 5 d/wk; total = 20 wk	17.2% (10/58); RRIs reported in 0% (0/15), 12.0% (3/25), and 38.9% (7/18) of 1, 3, and 5-d/wk groups, respectively	Running frequency: ↑ Running frequency (5×/wk) associated with ↑ RRI risk