Memphis's Biggest 5K Delivers Fast Flat Miles for a Cause Worth Running

Roughly 4,500 to 4,700 runners take to the streets of downtown Memphis each December for a point-to-point 5K that threads through the St. Jude Children's Research Hospital campus before finishing on a gentle downhill stretch of Union Ave. adjacent to AutoZone Park. With a field median around 50–52 minutes and a top-10% cutoff under 32:15, the race draws an enormous range of abilities — all raising money for what organizers call the largest single-day fundraising event for St. Jude.

By the numbers

The field has been remarkably stable across the two most recent editions: 4,699 finishers in 2024 and 4,565 in 2025. Women make up a clear majority — 3,071 in 2024 and 2,937 in 2025 — consistent with the broader trend in road racing. The overall median tightened slightly year over year, from 51:51 in 2024 to 50:30 in 2025, though the conditions in those two years differed enough to complicate a direct comparison. The men's median moved from 46:04 to 44:52; the women's from 53:54 to 52:55.

How the course runs

The course is flat — GPS data confirms no sustained climb or descent of any consequence, with a net change of just -25 feet across the full 3.1 miles. Runners start on B.B. King Blvd., pass through the St. Jude campus near the midpoint, and finish downhill on Union Ave. There is no terrain-driven reason to bank time early or brace for a climb late; the course simply asks you to run it.

The fade curve tells the real story. Looking at the 2025 edition, the field's median segment pace through the first 1.55 miles was 15:21/mi, slowing to 16:50/mi over the back half — a meaningful deceleration across a very large, mixed-ability field.

Pacing patterns

Back-half slowdown is the norm across mass-participation road races, and this field is no exception. In 2025, 85% of finishers ran a positive split, with an average second-half slowdown of 11.9%. That figure was notably steeper than 2024's 7.7% slowdown, when 80% of the field went positive. The difference tracks with conditions: 2025 brought misty, near-freezing air at ~34°F and 94% humidity, while 2024 was colder at the gun (~31°F) but drier and calmer at 63% humidity and 7 mph wind. Even in the friendlier 2024 conditions, four in five runners still slowed over the second half — a reminder that going out conservatively through the St. Jude campus pays off regardless of the weather.

The weather question

Both editions on record were cold December mornings in Memphis. The 2024 start sat at 31°F with light wind and low humidity; 2025 was slightly warmer at 34°F but far more humid — 94% — with mist. The mistier, more saturated air in 2025 coincided with the larger average slowdown. December 5, 2026 falls on the same early-December slot, so temperatures in the low-to-mid 30s at the 7:00 a.m. gun are a reasonable baseline expectation. Layering for the first mile and planning for the possibility of precipitation is prudent.

What it takes

Breaking 32 minutes puts a runner in the top tenth of this field. The top quarter requires something under 39:36 on the slower end. The men's winning times have improved each year on record — from 17:38 in 2023 to 17:05 in 2024 to 16:30 in 2025 — suggesting the front of the race is getting sharper.

What to watch

The men's winning times have dropped in each of the three listed editions. Whether that trajectory continues in 2026, and whether any runner can push into the mid-15s, is the clearest competitive question the data raises. On the women's side, the winning times have varied more — 18:52, 19:04, 20:21 across the three years — leaving the front of the women's race genuinely open. Field size is worth tracking too: after a slight dip from 2024 to 2025, whether the race returns toward or above 4,700 finishers will signal whether participation is holding or growing. And given how sharply the 2025 field faded in the mist, a drier December morning in 2026 could push the overall median meaningfully lower.