IRONMAN 70.3 Michigan has been voted best bike course globally and a top ten overall race by athletes multiple years running, and it's easy to see why once you're on the ground. This isn't a course that beats you up with elevation. It's a course that rewards riders who understand wind, know how to hold a smart number on the exposed stretches of M-22, and don't let a fast start on the way out cost them on the way back.
Race Overview
IRONMAN 70.3 Michigan has called Frankfort home since 2021, after relocating from its original venue in Traverse City. The move has been a clear win for both the town and the race. Frankfort sits directly on Betsie Bay where it meets Lake Michigan, and the event has since been recognized in the IRONMAN 70.3 Athletes' Choice Awards for Best Race Venue, Best Bike Course, and one of the best finish lines in the sport.
Recent editions have sold out well ahead of race day with competitors from across the country and beyond for a weekend built around small town hospitality, sunset views from the pier, and a genuinely fast, honest course.
Course Description
Swim: The 1.2 mile swim is a single loop held entirely within the protected waters of Betsie Bay, starting and finishing right next to the transition area. Sheltered from Lake Michigan's open water, the bay tends to stay calm even when the big lake doesn't, and the swim is typically wetsuit legal given how cool the water runs this far north in September. It's a straightforward, low drama start to the day, which means most athletes arrive at T1 with the bulk of their focus still ahead of them.
Bike: The 56 mile bike course is a single loop built around M-22, the scenic highway that traces the Lake Michigan shoreline through Benzie County, with two out and back sections woven into the route. Official course data lists a start and finish elevation of 592 ft with roughly 1,239 ft of gain across the full 56 miles, so this is a rolling course rather than a flat one, but nothing on it looks like a mountain stage. The terrain is mostly gentle rollers and open farm and forest road, and the real variable here isn't the hills, it's the wind coming off the lake. Because the course runs out and back rather than a loop, a headwind heading north can flip into a tailwind on the return, and riders who don't plan for that asymmetry tend to either underpace the outbound leg or overcook it and pay for it later. The roads themselves are well maintained and the course has consistently rated as one of the best bike legs in the sport, a combination of scenery and smooth, fast pavement that's hard to find elsewhere.
Run: The 13.1 mile run is two out and back loops on paved trails and roads that connect the City of Frankfort with the Village of Elberta, tracing the shoreline of Betsie Bay for most of the route. It's a mostly flat, rolling course with none of the standout climbs you'd find on a hillier 70.3, which makes it a run course where fitness and pacing discipline matter more than terrain management. The two loop format means you'll pass through the busiest sections of town, and the finish line energy, twice, which locals and past athletes both point to as one of the more memorable parts of race day.
Forecasted Weather
Late September in Frankfort sits right at the seasonal turn from summer into fall. Average daytime highs typically land in the mid 60s°F (18-19°C), with overnight and early morning lows dropping into the upper 40s to low 50s°F (8-11°C), so expect a cool, possibly brisk start on the swim and early bike before things warm through the morning. Lake Michigan's moderating effect keeps temperature swings from getting too extreme in either direction, but conditions can still shift quickly this close to the water, and September in this part of Michigan sees a meaningful number of rainy days across the month, so building a plan that accounts for the actual race week forecast rather than the seasonal average is worth the extra step.
Water temperature in Betsie Bay this time of year typically sits cool enough that wetsuits are likely, though as always, confirm with race morning readings. Wind is the detail that matters most for this course. The open stretches of M-22 along the shoreline are exposed, and because the bike is built around out and back sections rather than a simple loop, a headwind in one direction becomes a tailwind in the other. A pacing plan built on flat, still air assumptions will not hold up well here.
Why This Course Rewards a Best Bike Split Plan
Michigan's bike leg isn't difficult because of hills, it's difficult because of wind, and wind is exactly the kind of variable that flat power targets get wrong. A BBS race plan for IRONMAN 70.3 Michigan 2026 will:
- Model the out-and-back wind asymmetry. A headwind heading out and a tailwind coming back (or vice versa) isn't something you can pace evenly through. BBS builds your power targets around the actual direction and strength of the forecasted wind on each leg, so you're not left guessing why the return trip felt too easy or too hard.
- Set a run-protective power target. With a rolling but honest run course waiting at T2, this isn't a race to bank time on the bike and hope the legs hold up. BBS balances your bike pacing against your predicted run performance so your watt targets reflect your fastest overall finish, not just your fastest bike split.
- Account for the rolling terrain realistically. The 1,239 ft of gain across 56 miles isn't dramatic, but it's not nothing either. A segment-aware plan smooths out the small climbs and descents so you're not surging and coasting your way through rollers that are better ridden at a steady, sustainable effort.
- Give you a clear, honest number for race morning. Cool, potentially damp conditions on a course this exposed can tempt riders into either overdressing and overheating or underestimating how much the wind will cost them. A BBS plan built on the actual race week forecast keeps your effort honest from the first pedal stroke to T2.
Interactive Race Plan and Course Map
This power plan was modeled for an athlete with an average CdA of 0.2548, an FTP of 300 watts and weighing 165 lbs. Want to see what your time would be on the IRONMAN 70.3 Michigan course? Try the Time Analysis feature below, where you can quickly adjust Drag, Power, Weight and Crr to your own values. Check out our demo race plan to see what a premium race plan looks like.
| Interval | Int. Time | Total Time | Int. Dist. | Total Dist. | Grade | Speed | Power |
|---|---|---|---|---|---|---|---|
| #1 | 00:15:41 | 00:15:41 | 5.74 mi | 5.74 mi | +0.19 % | 21.93 mph | 241 w |
| #2 | 00:01:18 | 00:17:00 | 0.63 mi | 6.37 mi | -1.52 % | 28.99 mph | 200 w |
| #3 | 00:10:49 | 00:27:49 | 4.80 mi | 11.17 mi | -0.01 % | 26.59 mph | 228 w |
| #4 | 00:01:40 | 00:29:29 | 0.53 mi | 11.70 mi | +1.63 % | 19.02 mph | 266 w |
| #5 | 00:00:44 | 00:30:14 | 0.18 mi | 11.88 mi | +4.79 % | 14.43 mph | 297 w |
| #6 | 00:00:52 | 00:31:06 | 0.28 mi | 12.16 mi | +0.22 % | 19.37 mph | 244 w |
| #7 | 00:00:55 | 00:32:02 | 0.18 mi | 12.34 mi | +5.79 % | 11.80 mph | 298 w |
| #8 | 00:00:21 | 00:32:23 | 0.12 mi | 12.46 mi | -3.22 % | 20.59 mph | 191 w |
| #9 | 00:00:08 | 00:32:32 | 0.06 mi | 12.52 mi | -0.14 % | 24.85 mph | 240 w |
| #10 | 00:00:41 | 00:33:14 | 0.22 mi | 12.74 mi | +1.71 % | 19.12 mph | 265 w |
| #11 | 00:00:06 | 00:33:20 | 0.03 mi | 12.77 mi | +0.03 % | 18.84 mph | 238 w |
| #12 | 00:00:42 | 00:34:03 | 0.39 mi | 13.16 mi | -4.98 % | 32.98 mph | 156 w |
| #13 | 00:00:17 | 00:34:20 | 0.14 mi | 13.30 mi | +1.86 % | 28.79 mph | 264 w |
| #14 | 00:00:29 | 00:34:50 | 0.22 mi | 13.52 mi | -4.10 % | 26.48 mph | 180 w |
| #15 | 00:00:13 | 00:35:03 | 0.10 mi | 13.62 mi | +1.34 % | 25.92 mph | 258 w |
| #16 | 00:06:55 | 00:41:59 | 2.46 mi | 16.08 mi | -0.03 % | 21.26 mph | 241 w |
| #17 | 00:01:10 | 00:43:09 | 0.38 mi | 16.46 mi | +1.20 % | 19.31 mph | 259 w |
| #18 | 00:28:33 | 01:11:43 | 10.49 mi | 26.95 mi | -0.01 % | 22.03 mph | 239 w |
| #19 | 00:02:34 | 01:14:18 | 0.72 mi | 27.67 mi | +2.42 % | 16.65 mph | 276 w |
| #20 | 00:04:54 | 01:19:13 | 1.75 mi | 29.42 mi | +0.35 % | 21.38 mph | 243 w |
| #21 | 00:00:24 | 01:19:38 | 0.18 mi | 29.60 mi | -2.60 % | 25.63 mph | 195 w |
| #22 | 00:02:19 | 01:21:57 | 0.88 mi | 30.48 mi | +0.23 % | 22.78 mph | 239 w |
| #23 | 00:00:09 | 01:22:06 | 0.06 mi | 30.54 mi | +2.99 % | 23.70 mph | 278 w |
| #24 | 00:03:49 | 01:25:55 | 1.73 mi | 32.27 mi | -0.43 % | 27.20 mph | 221 w |
| #25 | 00:00:59 | 01:26:55 | 0.31 mi | 32.58 mi | +4.43 % | 18.63 mph | 325 w |
| #26 | 00:00:12 | 01:27:08 | 0.06 mi | 32.64 mi | +1.81 % | 17.66 mph | 266 w |
| #27 | 00:00:40 | 01:27:48 | 0.28 mi | 32.92 mi | -1.13 % | 25.26 mph | 208 w |
| #28 | 00:00:06 | 01:27:54 | 0.05 mi | 32.97 mi | -2.97 % | 29.64 mph | 175 w |
| #29 | 00:00:44 | 01:28:38 | 0.28 mi | 33.25 mi | +2.89 % | 22.40 mph | 278 w |
| #30 | 00:00:10 | 01:28:49 | 0.06 mi | 33.31 mi | +1.23 % | 19.44 mph | 251 w |
| #31 | 00:00:22 | 01:29:11 | 0.17 mi | 33.48 mi | -2.79 % | 26.78 mph | 179 w |
| #32 | 00:00:06 | 01:29:18 | 0.06 mi | 33.54 mi | -0.37 % | 30.55 mph | 221 w |
| #33 | 00:01:21 | 01:30:39 | 0.44 mi | 33.98 mi | +1.10 % | 19.57 mph | 253 w |
| #34 | 00:00:37 | 01:31:17 | 0.28 mi | 34.26 mi | -3.04 % | 26.79 mph | 189 w |
| #35 | 00:01:05 | 01:32:23 | 0.38 mi | 34.64 mi | +1.18 % | 21.10 mph | 258 w |
| #36 | 00:00:38 | 01:33:01 | 0.31 mi | 34.95 mi | -4.35 % | 28.81 mph | 177 w |
| #37 | 00:00:06 | 01:33:08 | 0.06 mi | 35.01 mi | -2.22 % | 31.91 mph | 204 w |
| #38 | 00:05:43 | 01:38:51 | 2.10 mi | 37.11 mi | +0.30 % | 22.05 mph | 241 w |
| #39 | 00:01:11 | 01:40:03 | 0.51 mi | 37.62 mi | -0.38 % | 25.89 mph | 220 w |
| #40 | 00:00:41 | 01:40:44 | 0.24 mi | 37.86 mi | +1.72 % | 20.67 mph | 261 w |
| #41 | 00:03:49 | 01:44:34 | 1.72 mi | 39.58 mi | -0.35 % | 27.03 mph | 221 w |
| #42 | 00:01:34 | 01:46:08 | 0.86 mi | 40.44 mi | -2.11 % | 32.73 mph | 188 w |
| #43 | 00:20:36 | 02:06:45 | 9.68 mi | 50.12 mi | -0.02 % | 28.19 mph | 224 w |
| #44 | 00:01:29 | 02:08:15 | 0.63 mi | 50.75 mi | +0.90 % | 25.36 mph | 256 w |
| #45 | 00:06:06 | 02:14:21 | 2.88 mi | 53.63 mi | -0.15 % | 28.34 mph | 221 w |
| #46 | 00:00:06 | 02:14:28 | 0.05 mi | 53.68 mi | -2.21 % | 26.99 mph | 186 w |
| #47 | 00:00:05 | 02:14:34 | 0.04 mi | 53.72 mi | -0.34 % | 28.23 mph | 219 w |
| #48 | 00:00:28 | 02:15:02 | 0.17 mi | 53.89 mi | +4.35 % | 21.41 mph | 316 w |
| #49 | 00:00:10 | 02:15:13 | 0.05 mi | 53.94 mi | +3.17 % | 16.60 mph | 287 w |
| #50 | 00:00:21 | 02:15:35 | 0.14 mi | 54.08 mi | -1.92 % | 23.51 mph | 192 w |
| #51 | 00:01:27 | 02:17:02 | 0.34 mi | 54.42 mi | +5.39 % | 13.97 mph | 300 w |
| #52 | 00:00:17 | 02:17:20 | 0.08 mi | 54.50 mi | +1.23 % | 16.44 mph | 264 w |
| #53 | 00:00:48 | 02:18:09 | 0.34 mi | 54.84 mi | -0.46 % | 25.51 mph | 218 w |
| #54 | 00:00:08 | 02:18:17 | 0.06 mi | 54.90 mi | +2.99 % | 25.93 mph | 287 w |
| #55 | 00:00:16 | 02:18:33 | 0.12 mi | 55.02 mi | -5.75 % | 27.00 mph | 58 w |
| #56 | 00:00:06 | 02:18:40 | 0.06 mi | 55.08 mi | -5.89 % | 35.38 mph | 35 w |
| #57 | 00:00:27 | 02:19:07 | 0.24 mi | 55.32 mi | +0.08 % | 32.27 mph | 228 w |
| #58 | 00:00:18 | 02:19:25 | 0.17 mi | 55.49 mi | -4.83 % | 32.56 mph | 160 w |
| #59 | 00:01:07 | 02:20:32 | 0.58 mi | 56.07 mi | -1.67 % | 30.99 mph | 200 w |
| #60 | 00:00:15 | 02:20:48 | 0.09 mi | 56.16 mi | -0.27 % | 20.96 mph | 238 w |
| Totals/Avg | 02:20:48 | 02:20:48 | 56.17 mi | 56.17 mi | -0.05% | 23.94 mph | 235.28 w |
Climb Summary by Category
| Category | Climb Count | Total Time | Total Dist. | Avg. Time | Avg. Dist. | Avg. Grade | Avg. Speed | Avg. Power |
|---|---|---|---|---|---|---|---|---|
| Cat4 | 5 | 00:05:17 | 1.37 mi | 00:01:03 | 0.27 mi | 4.65 % | 15.84 mph | 295 w |
| All Cats | 5 | 00:05:17 | 1.37 mi | 00:01:03 | 0.27 mi | 4.65 % | 15.84 mph | 295 w |
| Climb | Start Time | Start Dist. | Duration | Distance | Speed | Power | Grade | Elevation Gain | Category |
|---|---|---|---|---|---|---|---|---|---|
| #1 | 00:29:29 | 11.69 mi | 00:00:44 | 0.18 mi | 14.43 mph | 297 w | 4.79 % | 45 ft | Cat4 |
| #2 | 00:31:06 | 12.15 mi | 00:00:55 | 0.18 mi | 11.80 mph | 297 w | 5.80 % | 56 ft | Cat4 |
| #3 | 01:25:55 | 32.26 mi | 00:01:12 | 0.37 mi | 18.46 mph | 296 w | 3.99 % | 78 ft | Cat4 |
| #4 | 02:14:34 | 53.72 mi | 00:00:39 | 0.22 mi | 20.10 mph | 302 w | 4.09 % | 47 ft | Cat4 |
| #5 | 02:15:35 | 54.09 mi | 00:01:45 | 0.42 mi | 14.39 mph | 282 w | 4.58 % | 102 ft | Cat4 |
Build your own personalized IRONMAN 70.3 Michigan power plan today! Sign up for a free Athlete Basic account to get started with your athlete profile and bike setup, then grab the IRONMAN 70.3 Michigan course to model your own race plan.
IRONMAN 70.3 Michigan FAQs
Your target power depends on your FTP, body weight, bike setup, and finish time goal — not a generic number that applies to every rider. The variables that matter most are your current fitness, your aerodynamic position, and the specific demands of the IRONMAN 70.3 Michigan course. The best approach is to build a personalized plan in Best Bike Split using your actual athlete profile — you'll get a segment-by-segment power target based on your specific inputs rather than a one-size-fits-all recommendation.
Every course is different and requires its own unique pacing plan. On a multi-loop course, fatigue and wind shift between laps and what felt comfortable early can become unsustainable later. On an out-and-back, headwind in one direction becomes tailwind in the other — an asymmetry a flat power target can't account for. On a point-to-point or single-loop course, you only get one pass at every section with no opportunity to recalibrate. When you create a Best Bike Split race plan for IRONMAN 70.3 Michigan, we model the specific demands of that course so your pacing strategy reflects the race you're actually doing.
Significantly — and the effect varies depending on the course profile. On flatter courses, wind and aerodynamics become the dominant variables in your speed equation, more so than on courses where gradient naturally dictates effort. On climbing-heavy courses, your power-to-weight ratio and how you manage the descents matter most. A Best Bike Split race plan lets you model the specific conditions forecasted for IRONMAN 70.3 Michigan, so your targets reflect what you'll actually face on race day rather than what the course looks like on paper.
It depends on the course and how well you pace it. Flat, fast courses offer genuine PR potential but only if you execute correctly — without terrain to naturally regulate your effort, going out too hard early is easy and costly. Technical or hilly courses reward smart segment-by-segment pacing over raw fitness. Either way, a physics-based race plan from Best Bike Split gives you a realistic split prediction based on your actual profile so you know before race day what a well-executed bike leg looks like for you specifically.
Yes — and this is one of the most underused features. Once you've built your IRONMAN 70.3 Michigan race plan, you can export it directly to Zwift, TrainerRoad, or any ERG-mode trainer for indoor sessions, or push it to your Garmin, Wahoo, or Karoo for outdoor rides. Training on your actual race plan means you arrive at IRONMAN 70.3 Michigan already knowing what your target effort feels like at every section of the course — not just what the number says on paper.
