Your plan in four answers
Great Springs Natural Bridge Caverns has not announced its next date, so we have estimated September. Change the date below once you know it.
- Distances
- 16 miles, 100 miles
- Terrain
- Rolling
Course
The Great Springs Natural Bridge Caverns course
The headline event is a Last Person Standing (backyard) race: runners start a 4.1667-mile (6.706 km) loop from the race hub arch every hour on the hour, anyone who cannot finish a loop within the hour or misses the next start is out, and the race ends when one runner remains, with 24 loops making 100 miles. Ruckers do the same on a 2.47-mile loop carrying a 20 or 30 lb pack.
Read the full course notes
The loop winds over flowing hills and through wooded landscape at Natural Bridge Caverns, between San Antonio and New Braunfels, and the organizers call it the toughest Last Person Standing course in Texas. Alongside it, 4, 8 and 16 mile trail races start inside the caverns with a quarter mile underground before surfacing for the trail loop. Course marking is thorough and reflective for the night hours, and the race is cupless, so bring your own cup or bottle.
- Terrain
- Rolling
- Distances
- 16 miles, 100 miles
- Weather on race day
- Late September around San Antonio is usually still hot: mornings around 68–75 °F, afternoon highs near 90 °F, often humid, with nights cooling into the upper 60s. For a race that runs through the heat of the day and into the night, plan electrolytes, ice and shade at your hub station, and slow your loop pace in the afternoon.
What to train for
Backyard racing rewards an easy, repeatable loop rather than speed: practice covering 4.17 miles of hilly trail in about 50 to 55 minutes, then resting and starting again on the hour.
Build back-to-back long days and at least one 6 to 8 hour session of hourly loops to rehearse eating, changing socks and getting out of your chair on time.
Train in the Texas heat on wooded, hilly trail, and include night runs with a headlamp. Set up your hub like a personal aid station so every minute between loops counts.
Sample week
A sample Great Springs Natural Bridge Caverns training week
A week from the middle of the build, about six weeks out. Your plan sets the real distances and paces from your own fitness and adjusts them every week as you train.
- Monday
- Rest, or 20 minutes of mobility
- Tuesday Key session
- Intervals: 5 × 1 km at 5K to 10K effort, easy jog between
- Wednesday
- Easy run, 5–6 mi
- Thursday Key session
- Goal-pace run, 7 mi with 4 mi at race pace
- Friday
- Recovery run, 4 mi, or cross-train
- Saturday Key session
- Long run, 10–12 mi easy
- Sunday
- Easy run, 4 mi, then 6 relaxed strides
Taper
Tapering for the Great Springs Natural Bridge Caverns
Start the taper ten to fourteen days before race day. Cut your weekly volume by about a third, then by half in race week, and keep a few short efforts at race pace so your legs stay sharp. The course rolls, so keep one short session on undulating ground in the first taper week.
Also in Claude
Ask Claude for this plan
Add AthleteSpace to Claude once, then paste this prompt and put in your own numbers.
Build me a training plan for the Great Springs Trail Race - Natural Bridge Caverns (16 miles) in September. I run [distance] a week, [days] days a week, easy pace [pace].
Great Springs Natural Bridge Caverns training questions
How long should I train for the Great Springs Natural Bridge Caverns?
Most runners give a 16-mile twelve to sixteen weeks of focused training on top of an existing base. The plan above counts back from your actual race date, so if you have less time than that it builds the best plan the remaining weeks allow rather than pretending you have longer.
Is the Great Springs Natural Bridge Caverns course hilly?
Rolling. The headline event is a Last Person Standing (backyard) race: runners start a 4.1667-mile (6.706 km) loop from the race hub arch every hour on the hour, anyone who cannot finish a loop within the hour or misses the next start is out, and the race ends when one runner remains, with 24 loops making 100 miles.
What is the weather usually like at the Great Springs Natural Bridge Caverns?
Late September around San Antonio is usually still hot: mornings around 68–75 °F, afternoon highs near 90 °F, often humid, with nights cooling into the upper 60s. For a race that runs through the heat of the day and into the night, plan electrolytes, ice and shade at your hub station, and slow your loop pace in the afternoon.
When should I start tapering for the Great Springs Natural Bridge Caverns?
Start the taper ten to fourteen days before race day. Cut your weekly volume by about a third, then by half in race week, and keep a few short efforts at race pace so your legs stay sharp. The course rolls, so keep one short session on undulating ground in the first taper week.
Do I need an account to get a Great Springs Natural Bridge Caverns training plan?
No. The plan above builds in your browser with no account, no email, and no card. Make a free account only if you want to keep it, log your runs against it, and have the coach keep adapting it as your training goes.