Swimmer profile
Mason Kostov
Male15-16Asphalt Green Unified AquaticsMR · EASTERN
SeasonUSA Swimming season runs Sept – Aug
Event
2018–19
2021–22
2022–23
2023–24
2024–25
2025–26
50 Free LCM
39.03
28.91
▲ 10.12
26.33
▲ 2.58
25.16
▲ 1.17
25.21
▼ 0.05
26.15
▼ 0.94
100 Free LCM
—
1:06.71
58.62
▲ 8.09
56.28
▲ 2.34
55.77
▲ 0.51
58.05
▼ 2.28
200 Free LCM
—
2:28.54
2:17.09
▲ 11.45
2:10.86
▲ 6.23
2:08.22
▲ 2.64
—
400 Free LCM
—
—
—
4:47.96
—
—
50 Back LCM
49.40
37.03
▲ 12.37
32.88
▲ 4.15
—
31.71
▲ 1.17
—
100 Back LCM
—
1:19.07
1:15.12
▲ 3.95
1:09.77
▲ 5.35
1:09.23
▲ 0.54
1:12.41
▼ 3.18
200 Back LCM
—
2:53.67
—
2:37.52
▲ 16.15
—
—
50 Breast LCM
—
40.59
35.18
▲ 5.41
33.84
▲ 1.34
34.49
▼ 0.65
—
100 Breast LCM
1:58.47
1:30.90
▲ 27.57
1:22.67
▲ 8.23
1:15.39
▲ 7.28
1:17.96
▼ 2.57
—
200 Breast LCM
—
—
3:08.14
2:51.61
▲ 16.53
2:59.51
▼ 7.90
—
50 Fly LCM
—
34.97
30.16
▲ 4.81
29.21
▲ 0.95
28.31
▲ 0.90
30.15
▼ 1.84
100 Fly LCM
—
1:21.52
1:11.36
▲ 10.16
1:06.15
▲ 5.21
1:06.09
▲ 0.06
1:07.74
▼ 1.65
200 IM LCM
—
2:49.36
2:30.95
▲ 18.41
2:22.69
▲ 8.26
2:27.50
▼ 4.81
—
400 IM LCM
—
—
—
5:28.59
—
—
Improvement<0.5s0.5–2s2–5s5s+Slower
📊 All Attempts by Event
Chronological history of every recorded swim. Click an event to expand its attempt list.