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BOSTON MARATHON 2025

Derek Lai

Bib: 8055•M

ON

0:00
0:00
/ mi
Masters
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Overall
#0 / 28404
Top 16%
Gender (Male)
#0 / 16105
Top 26%
Masters (Masters Men)
#0 / 10463
Top 13%
Division (M45-49)
#0 / 2386
Top 16%
Race Day Weather
50°/40°F
broken clouds

⏱️ Race Timeline

Start
0:00:00
Race begins
5K· 3.11 mi
20:52
Rank: #5570
Start → 5K
20:52 | 6:43/mi
10K· 6.21 mi
41:55
Rank: #5787 (-217)
5K → 10K
21:03 | 6:47/mi
15K· 9.32 mi
1:02:59
Rank: #5774 (+13)
10K → 15K
21:04 | 6:47/mi
20K· 12.43 mi
1:24:10
Rank: #5689 (+85)
15K → 20K
21:11 | 6:49/mi
Half· 13.11 mi
1:28:46
Rank: #5689
20K → Half
4:36 | 6:45/mi
25K· 15.53 mi
1:45:21
Rank: #5551 (+138)
Half → 25K
16:35 | 6:50/mi
30K· 18.64 mi
2:06:59
Rank: #5265 (+286)
25K → 30K
21:38 | 6:58/mi
20M
2:16:39
Rank: #5204 (+61)
30K → 20M
9:40 | 7:07/mi
21M
2:24:04
Rank: #5096 (+108)
20M → 21M
7:25 | 7:25/mi
35K· 21.75 mi
2:29:10
Rank: #5055 (+41)
21M → 35K
5:06 | 6:49/mi
23M
2:37:57
Rank: #4944 (+111)
35K → 23M
8:47 | 7:01/mi
24M
2:44:47
Rank: #4849 (+95)
23M → 24M
6:50 | 6:50/mi
40K· 24.85 mi
2:50:43
Rank: #4769 (+80)
24M → 40K
5:56 | 6:56/mi
25.2M
2:53:12
Rank: #4702 (+67)
40K → 25.2M
2:29 | 7:12/mi
Finish· 26.22 mi
2:59:50
Rank: #4638 (+64)
25.2M → Finish
6:38 | 6:31/mi

The Course

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Half Splits

1st Half· via HalfFaster
Distance13.11 mi
Time1:28:46
Pace6:46 /mi
2nd Half
Distance13.11 mi
Time1:31:04
Pace6:57 /mi
📊Positive Split: 2.6% slower second half

Checkpoint Splits

CheckpointDistanceTime of DayTimeAvg PaceSegment TimeSegment PaceDiff
5K
3.11 mi10:29:0520:526:4320:52
6:43
-
10K
6.21 mi10:50:0841:556:4521:03
6:47
+0:04
15K
9.32 mi11:11:121:02:596:4521:04
6:47
0:00
20K
12.43 mi11:32:231:24:106:4621:11
6:49
+0:02
Half
13.11 mi11:36:591:28:466:464:36
6:45
-0:04
25K
15.53 mi11:53:341:45:216:4716:35
6:50
+0:05
30K
18.64 mi12:15:122:06:596:4921:38
6:58
+0:08
20M
20.00 mi12:24:522:16:396:509:40
7:07
+0:09
21M
21.00 mi12:32:172:24:046:527:25
7:25
+0:18
35K
21.75 mi12:37:232:29:106:525:06
6:49
-0:36
23M
23.00 mi12:46:102:37:576:528:47
7:01
+0:12
24M
24.00 mi12:53:002:44:476:526:50
6:50
-0:11
40K
24.85 mi12:58:562:50:436:525:56
6:56
+0:06
25.2M
25.20 mi13:01:252:53:126:522:29
7:12
+0:16
Finish
26.22 mi13:08:032:59:506:526:38
6:31
-0:41

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

6:31 /mi

Average Pace

6:52 /mi

Slowest Pace

7:25 /mi

Loading chart...
Fastest
Middle
Slowest
Average

📊Segments

Segment Time Comparison

Time at Faster Pace

2:49:56

94% of race

Time at Steady Pace

9:54

6% of race

Time at Slower Pace

0:00

0% of race

Average Pace: 6:52 /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 mi10:29:0520:526:4320:52
6:43
#5570
10K
6.21 mi10:50:0841:556:4521:03
6:47
#5787
15K
9.32 mi11:11:121:02:596:4521:04
6:47
#5774
20K
12.43 mi11:32:231:24:106:4621:11
6:49
#5689
Half
13.11 mi11:36:591:28:466:464:36
6:45
#5689
25K
15.53 mi11:53:341:45:216:4716:35
6:50
#5551
30K
18.64 mi12:15:122:06:596:4921:38
6:58
#5265
20M
20.00 mi12:24:522:16:396:509:40
7:07
#5204
21M
21.00 mi12:32:172:24:046:527:25
7:25
#5096
35K
21.75 mi12:37:232:29:106:525:06
6:49
#5055
23M
23.00 mi12:46:102:37:576:528:47
7:01
#4944
24M
24.00 mi12:53:002:44:476:526:50
6:50
#4849
40K
24.85 mi12:58:562:50:436:525:56
6:56
#4769
25.2M
25.20 mi13:01:252:53:126:522:29
7:12
#4702
Finish
26.22 mi13:08:032:59:506:526:38
6:31
#4638
Faster pace
Steady pace
Slower pace

Checkpoint and Segment Rankings

CheckpointDistanceSeg. DistOverallMalesM45-49Seg. OverallSeg. MalesSeg. M45-49
5K3.11 mi3.11 mi5570515551555868(Top 21%)5342(Top 33%)5342(Top 224%)
10K6.21 mi3.10 mi5787-2175333-1785333-1786089(Top 21%)5551(Top 34%)5551(Top 233%)
15K9.32 mi3.11 mi5774+135309+245309+245868(Top 21%)5342(Top 33%)5342(Top 224%)
20K12.43 mi3.11 mi5689+855222+875222+875460(Top 19%)4987(Top 31%)4987(Top 209%)
Half13.11 mi0.68 mi56895223-15223-15559(Top 20%)5079(Top 32%)5079(Top 213%)
25K15.53 mi2.42 mi5551+1385101+1225101+1225173(Top 18%)4739(Top 29%)4739(Top 199%)
30K18.64 mi3.11 mi5265+2864837+2644837+2644462(Top 16%)4080(Top 25%)4080(Top 171%)
20M20.00 mi1.36 mi5204+614773+644773+644716(Top 17%)4257(Top 26%)4257(Top 178%)
21M21.00 mi1.00 mi5096+1084679+944679+944179(Top 15%)3758(Top 23%)3758(Top 158%)
35K21.75 mi0.75 mi5055+414641+384641+384184(Top 15%)3737(Top 23%)3737(Top 157%)
23M23.00 mi1.25 mi4944+1114534+1074534+1073826(Top 13%)3439(Top 21%)3439(Top 144%)
24M24.00 mi1.00 mi4849+954443+914443+913691(Top 13%)3287(Top 20%)3287(Top 138%)
40K24.85 mi0.85 mi4769+804372+714372+713551(Top 13%)3147(Top 20%)3147(Top 132%)
25.2M25.20 mi0.35 mi4702+674310+624310+622145(Top 8%)1934(Top 12%)1934(Top 81%)
Finish26.22 mi1.02 mi4638+644253+574253+572865(Top 10%)2560(Top 16%)2560(Top 107%)

Segment Performance Analysis

10K→15K

0.0 - 3.1 mi

Top 21%
×21stories
+97ft-345ft

Overall

5868

Males

5342

M45-49

5342

5K→10K

3.1 - 6.2 mi

Top 21%
×5stories
+79ft-138ft

Overall

6089

Males

5551

M45-49

5551

10K→15K

6.2 - 9.3 mi

Top 21%
×3stories
+67ft-78ft

Overall

5868

Males

5342

M45-49

5342

15K→20K

9.3 - 12.4 mi

Top 19%
×5stories
+106ft-86ft

Overall

5460

Males

4987

M45-49

4987

20K→Half

12.4 - 13.1 mi

Top 20%
×2stories
+19ft-37ft

Overall

5559

Males

5079

M45-49

5079

Half→25K

13.1 - 15.5 mi

Top 18%
×4stories
+66ft-88ft

Overall

5173

Males

4739

M45-49

4739

25K→30K

15.5 - 18.6 mi

Top 16%
×9stories
+181ft-148ft

Overall

4462

Males

4080

M45-49

4080

30K→20M

18.6 - 20.0 mi

Top 17%
×5stories
+64ft-50ft

Overall

4716

Males

4257

M45-49

4257

20M→21M

20.0 - 21.0 mi

Top 15%
×8stories
+106ft-24ft

Overall

4179

Males

3758

M45-49

3758

21M→35K

21.0 - 21.8 mi

Top 15%
×7stories
+17ft-86ft

Overall

4184

Males

3737

M45-49

3737

35K→23M

21.8 - 23.0 mi

Top 13%
×5stories
+23ft-63ft

Overall

3826

Males

3439

M45-49

3439

23M→24M

23.0 - 24.0 mi

Top 13%
×6stories
+12ft-82ft

Overall

3691

Males

3287

M45-49

3287

24M→40K

24.0 - 24.9 mi

Top 13%
×1story
+6ft-20ft

Overall

3551

Males

3147

M45-49

3147

40K→25.2M

24.9 - 25.2 mi

Top 8%
×1story
+13ft-16ft

Overall

2145

Males

1934

M45-49

1934

25.2M→Finish

25.2 - 26.2 mi

Top 10%
×2stories
+22ft-21ft

Overall

2865

Males

2560

M45-49

2560

Passing Analysis

Category:
Athletes Passed
1716
Passed By
784
Net Change
+932
SegmentAthletes PassedPassed ByNet ChangeStart RankEnd Rank
Start → 5K----#5570
5K → 10K96313-217#5570#5787
10K → 15K129116+13#5787#5774
15K → 20K16984+85#5774#5689
20K → Half26260#5689#5689
Half → 25K17941+138#5689#5551
25K → 30K32236+286#5551#5265
30K → 20M10140+61#5265#5204
20M → 21M13830+108#5204#5096
21M → 35K6827+41#5096#5055
35K → 23M13524+111#5055#4944
23M → 24M11116+95#4944#4849
24M → 40K9818+80#4849#4769
40K → 25.2M692+67#4769#4702
25.2M → Finish7511+64#4702#4638
TOTALS1716784+932
📊

Passing Visuals

Category:
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🔥Passing Intensity

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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