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BOSTON MARATHON 2025

Mengdan Chu

Bib: 19666•F

MI

0:00
0:00
/ mi
Masters
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Overall
#0 / 28404
Gender (Female)
#0 / 12228
Top 44%
Masters (Masters Women)
#0 / 6759
Top 31%
Division (F55-59)
#0 / 994
Top 12%
Race Day Weather
50°/40°F
broken clouds

⏱️ Race Timeline

Course Elevation
7–469 ft
≈
×2stacked redwood trees
•▲ 890 ft climb · ▼ 1342 ft descent
Ribbon color based on
FasterSteadySlower· vs. your average pace
Start
0:00
Race begins
5K· 3.11 mi
7:58/mi
24:45
↑ 97↓ 3451.5%
10K· 6.21 mi
7:52/mi
49:11
↑ 79↓ 1380.4%
15K· 9.32 mi
7:52/mi
1:13:38
↑ 67↓ 78
20K· 12.43 mi
8:55/mi
1:41:19
↑ 106↓ 860.1%
Half· 13.11 mi
7:43/mi
1:46:35
↑ 19↓ 370.5%
25K· 15.53 mi
9:43/mi
2:10:08
↑ 66↓ 880.2%
30K· 18.64 mi
8:37/mi
2:36:53
↑ 181↓ 1480.2%
20M
8:40/mi
2:48:40
↑ 64↓ 500.2%
21M
8:51/mi
2:57:31
↑ 106↓ 241.6%
35K· 21.75 mi
8:39/mi
3:03:59
↑ 17↓ 861.7%
23M
8:30/mi
3:14:37
↑ 23↓ 630.6%
24M
8:09/mi
3:22:46
↓ 821.3%
40K· 24.85 mi
8:05/mi
3:29:41
↓ 200.3%
25.2M
8:13/mi
3:32:31
↑ 13↓ 160.2%
Finish· 26.22 mi
7:12/mi
3:39:51
↑ 22↓ 21

The Course

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Half Splits

1st Half· via HalfFaster
Distance13.11 mi
Time1:46:35
Pace8:08 /mi
2nd Half
Distance13.11 mi
Time1:53:16
Pace8:38 /mi
📊Positive Split: 6.3% slower second half

Checkpoint Splits

CheckpointDistanceTime of DayTimeAvg PaceSegment TimeSegment PaceDiff
5K
3.11 mi11:21:2324:457:5824:45
7:58
-
10K
6.21 mi11:45:4949:117:5524:26
7:52
-0:06
15K
9.32 mi12:10:161:13:387:5424:27
7:52
0:00
20K
12.43 mi12:37:571:41:198:0927:41
8:55
+1:03
Half
13.11 mi12:43:131:46:358:085:16
7:43
-1:12
25K
15.53 mi13:06:462:10:088:2323:33
9:43
+2:00
30K
18.64 mi13:33:312:36:538:2526:45
8:37
-1:06
20M
20.00 mi13:45:182:48:408:2611:47
8:40
+0:03
21M
21.00 mi13:54:092:57:318:278:51
8:51
+0:11
35K
21.75 mi14:00:373:03:598:286:28
8:39
-0:12
23M
23.00 mi14:11:153:14:378:2810:38
8:30
-0:09
24M
24.00 mi14:19:243:22:468:278:09
8:09
-0:21
40K
24.85 mi14:26:193:29:418:266:55
8:05
-0:04
25.2M
25.20 mi14:29:093:32:318:262:50
8:13
+0:08
Finish
26.22 mi14:36:293:39:518:237:20
7:12
-1:01

Checkpoints & Pacing

📈Pace Line

Pace Progression

Track your pace changes throughout the race. Dot colors mark your quickest to easiest segments, relative to your own pace.

Fastest Pace

7:12 /mi

Average Pace

8:23 /mi

Slowest Pace

9:43 /mi

Loading chart...
Fastest
Middle
Slowest
Average

📊Segments

Segment Time Comparison

Time at Faster Pace

1:01:29

28% of race

Time at Steady Pace

53:17

24% of race

Time at Slower Pace

1:45:05

48% of race

Average Pace: 8:23 /mi

Loading chart...
Faster pace (< avg)
Steady pace (≈ avg)
Slower pace (> avg)

🎨Heatmap

Pace Heatmap

Where you sped up and eased off relative to your own pace across the race. Colors are relative to your own range, not to other runners.

Loading...
0mi6.6mi13.1mi19.7mi26.2mi
Pace:
Faster
Steady
Slower

Click or hover over segments to see details

✨Sparklines

Checkpoint Splits with Pace Trends

Overall Pace Trend

CheckpointDistanceTime of DayTimeAvg PaceSegmentPaceTrendRank
5K
3.11 mi11:21:2324:457:5824:45
7:58
#16341
10K
6.21 mi11:45:4949:117:5524:26
7:52
#15839
15K
9.32 mi12:10:161:13:387:5424:27
7:52
#15506
20K
12.43 mi12:37:571:41:198:0927:41
8:55
#17056
Half
13.11 mi12:43:131:46:358:085:16
7:43
#16894
25K
15.53 mi13:06:462:10:088:2323:33
9:43
#18109
30K
18.64 mi13:33:312:36:538:2526:45
8:37
#17574
20M
20.00 mi13:45:182:48:408:2611:47
8:40
#17350
21M
21.00 mi13:54:092:57:318:278:51
8:51
#17042
35K
21.75 mi14:00:373:03:598:286:28
8:39
#17013
23M
23.00 mi14:11:153:14:378:2810:38
8:30
#16757
24M
24.00 mi14:19:243:22:468:278:09
8:09
#16539
40K
24.85 mi14:26:193:29:418:266:55
8:05
#16314
25.2M
25.20 mi14:29:093:32:318:262:50
8:13
#16157
Finish
26.22 mi14:36:293:39:518:237:20
7:12
#15822
Faster pace
Steady pace
Slower pace

Checkpoint and Segment Rankings

CheckpointDistanceSeg. DistOverallFemalesF55-59Seg. OverallSeg. FemalesSeg. F55-59
5K3.11 mi3.11 mi163415354535415004(Top 53%)4584(Top 37%)4584(Top 461%)
10K6.21 mi3.10 mi15839+5025044+3105044+31015411(Top 54%)4791(Top 39%)4791(Top 482%)
15K9.32 mi3.11 mi15506+3334854+1904854+19015004(Top 53%)4584(Top 37%)4584(Top 461%)
20K12.43 mi3.11 mi17056-15505777-9235777-92320531(Top 72%)7788(Top 64%)7788(Top 784%)
Half13.11 mi0.68 mi16894+1625677+1005677+10013679(Top 48%)3901(Top 32%)3901(Top 392%)
25K15.53 mi2.42 mi18109-12156419-7426419-74222537(Top 79%)8950(Top 73%)8950(Top 900%)
30K18.64 mi3.11 mi17574+5356167+2526167+25215461(Top 54%)5154(Top 42%)5154(Top 519%)
20M20.00 mi1.36 mi17350+2246054+1136054+11314893(Top 52%)4987(Top 41%)4987(Top 502%)
21M21.00 mi1.00 mi17042+3085901+1535901+15312648(Top 45%)3958(Top 32%)3958(Top 398%)
35K21.75 mi0.75 mi17013+295906-55906-516345(Top 58%)5965(Top 49%)5965(Top 600%)
23M23.00 mi1.25 mi16757+2565784+1225784+12213298(Top 47%)4436(Top 36%)4436(Top 446%)
24M24.00 mi1.00 mi16539+2185684+1005684+10012281(Top 43%)3951(Top 32%)3951(Top 397%)
40K24.85 mi0.85 mi16314+2255585+995585+9910845(Top 38%)3354(Top 27%)3354(Top 337%)
25.2M25.20 mi0.35 mi16157+1575501+845501+847290(Top 26%)1806(Top 15%)1806(Top 182%)
Finish26.22 mi1.02 mi15822+3355346+1555346+1557070(Top 25%)1688(Top 14%)1688(Top 170%)

Segment Performance Analysis

10K→15K

0.0 - 3.1 mi

Top 53%
×21story building
+97ft-345ft

Overall

15004

Females

4584

F55-59

4584

5K→10K

3.1 - 6.2 mi

Top 54%
×5story building
+79ft-138ft

Overall

15411

Females

4791

F55-59

4791

10K→15K

6.2 - 9.3 mi

Top 53%
×3story building
+67ft-78ft

Overall

15004

Females

4584

F55-59

4584

15K→20K

9.3 - 12.4 mi

Top 72%
×5story building
+106ft-86ft

Overall

20531

Females

7788

F55-59

7788

20K→Half

12.4 - 13.1 mi

Top 48%
×2story building
+19ft-37ft

Overall

13679

Females

3901

F55-59

3901

Half→25K

13.1 - 15.5 mi

Top 79%
×4story building
+66ft-88ft

Overall

22537

Females

8950

F55-59

8950

25K→30K

15.5 - 18.6 mi

Top 54%
×9story building
+181ft-148ft

Overall

15461

Females

5154

F55-59

5154

30K→20M

18.6 - 20.0 mi

Top 52%
×5story building
+64ft-50ft

Overall

14893

Females

4987

F55-59

4987

20M→21M

20.0 - 21.0 mi

Top 45%
×8story building
+106ft-24ft

Overall

12648

Females

3958

F55-59

3958

21M→35K

21.0 - 21.8 mi

Top 58%
×7story building
+17ft-86ft

Overall

16345

Females

5965

F55-59

5965

35K→23M

21.8 - 23.0 mi

Top 47%
×5story building
+23ft-63ft

Overall

13298

Females

4436

F55-59

4436

23M→24M

23.0 - 24.0 mi

Top 43%
×6story building
+12ft-82ft

Overall

12281

Females

3951

F55-59

3951

24M→40K

24.0 - 24.9 mi

Top 38%
×1story
+6ft-20ft

Overall

10845

Females

3354

F55-59

3354

40K→25.2M

24.9 - 25.2 mi

Top 26%
×1story
+13ft-16ft

Overall

7290

Females

1806

F55-59

1806

25.2M→Finish

25.2 - 26.2 mi

Top 25%
×2story building
+22ft-21ft

Overall

7070

Females

1688

F55-59

1688

Passing Analysis

Category:
Athletes Passed
3615
Passed By
3096
Net Change
+519
SegmentAthletes PassedPassed ByNet ChangeStart RankEnd Rank
Start → 5K----#16341
5K → 10K625123+502#16341#15839
10K → 15K40168+333#15839#15506
15K → 20K191569-1550#15506#17056
20K → Half1620+162#17056#16894
Half → 25K191234-1215#16894#18109
25K → 30K55722+535#18109#17574
30K → 20M23814+224#17574#17350
20M → 21M3102+308#17350#17042
21M → 35K7950+29#17042#17013
35K → 23M2637+256#17013#16757
23M → 24M2235+218#16757#16539
24M → 40K2272+225#16539#16314
40K → 25.2M1570+157#16314#16157
25.2M → Finish3350+335#16157#15822
TOTALS36153096+519
📊

Passing Visuals

Category:
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🔄Passing Circle

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🌊Position Flow

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🏃Race Lanes

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Public Race Data

Boston Athletic Association

Boston Athletic Association

Mika Timing

Mika Timing