What Is CTL, ATL, and TSB? The Ultra Runner's Guide to Training Load
CTL, ATL, and TSB tell you if you're getting fitter or just more tired. Learn how ultra runners use the Performance Management Chart to peak on race day.
Training tips, race strategies, nutrition guides, and stories from the trails. Expert content for trail runners and ultramarathon athletes.
CTL, ATL, and TSB tell you if you're getting fitter or just more tired. Learn how ultra runners use the Performance Management Chart to peak on race day.
The most demanding 100-miler in North America. 102.5 miles through the San Juan Mountains averaging 11,000 feet. 33,197 ft of gain. Handies Peak at 14,048 ft on 60-mile legs. Segment-by-segment strategy, aid station logistics, and the moves that define your race.
Every pole worth carrying — from the Black Diamond Distance Carbon Z to the Leki Ultratrail FX.One. Types, pros and cons, where the sport is trending, and a sortable comparison table. 14 poles compared.
Every vest worth carrying on long days in the mountains — from the Salomon ADV Skin to the Dynafit DNA 8 to the Nnormal Race Vest. Sortable by volume, weight, price, and bounce. 16 vests compared.
103.7 miles through the San Juan Mountains. 25,127 feet of climbing. A high point at 12,468 feet. Never drops below 8,428 feet. 11 aid stations across some of the most remote terrain in American ultra running. The name is a joke — this is one of the hardest 100-milers in the country.
Every shoe worth considering for long days in the mountains — drop, stack, grip, lug depth, key sponsored athlete, lifespan, and price. 25 shoes compared and sortable. Built for Mount to Coast, DC Peaks, Wasatch, and beyond.
Not all gels are created equal. From maltodextrin workhorses to dual-source super gels and hydrogel technology, here's the science of race-day fueling — including how David Roche consumed 152.5g of carbs per hour to set the Leadville 100 course record.
52.5 miles through the Oquirrh Mountains west of Tooele. 14,000 feet of vertical. 98% mining roads and ATV trails. Two summits of Porphyry Hill. A 10,006-foot Bald Mountain East summit at mile 45. The Lion Hill Loop — hit three times.
51.66 miles through the Wasatch Mountains above Provo. 13,580 feet of climbing. Five major climbs, snow patches in June, and a 4,000-foot descent off Windy Pass. Utah's oldest 50-miler with a 90% finish rate — 30 years running.
63.5 miles through the Tushar Mountains of southern Utah. 16,085 feet of climbing. Never drops below 8,855 feet. Every aid station, every descent, every rest section happens above the elevation where most races reach their hardest climbing. One of the toughest 100Ks in North America.
100 miles from Memory Grove Park below the Utah State Capitol to North Salt Lake. 20,869 feet of gain. A 5,768 ft overnight climb to Francis Peak with no crew for 34 miles. The newest 100 on the Wasatch Front — and already one of the hardest.
100 miles point-to-point from Logan, Utah to Bear Lake in Fish Haven, Idaho. 20,364 feet of gain. A 4,013 ft opening wall before sunrise. The tightest crew logistics of any Utah 100 — and the most beautiful fall colors you'll ever run through. Here's how the numbers break down.
100 miles point-to-point across the Wasatch Range. 26,000 feet of gain. A 4,400 ft wall in the first 7 miles. A high point at 10,462 ft that doesn't arrive until mile 72. The tightest cutoffs in Utah ultra running. Here's what the data says and how to race it.
100 miles with 26,000 feet of gain, averaging 8,700 feet the entire way. A high point at 12,272 feet on Mann's Peak. Temperature swings of 60+ degrees. The highest race in Utah — and one of the most underestimated. Here's what the data shows and how to race it.
101.78 miles. 21,600 feet of climbing. Two summit zones above 9,000 feet. A mandatory shuttle. No crew access for 40 miles. 2025 finishers called it harder than Bear and harder than Wasatch. Here's everything you need to know about the Goat Rattler 100.
101.78 miles. 21,600 feet of climbing. Two summit zones above 9,000 feet. A mandatory shuttle. No crew access for 40 miles. 2025 finishers called it harder than Bear and harder than Wasatch. Here's everything you need to know about the Goat Rattler 100.
You train your aerobic engine. You dial your nutrition. You study the course. But the one thing that keeps you moving at mile 40 isn't fitness — it's what you did before and after every run. The six stretches every ultra runner needs.
Everything your crew needs to know. GPS tracking, cutoff management, nutrition handoffs, and what to say at mile 70. The complete guide from HARDN.
A complete course recon breakdown of the DC Peaks 50 — 50 miles through Davis County's best trails with 11,000 feet of gain. Segment-by-segment strategy, aid station planning, cutoff analysis, and gear recommendations using HARDN's Course Recon tools.
There are races. And then there is Western States. Not because it's the hardest — because it means something most races never will. A complete course breakdown, segment-by-segment race strategy, and the history behind the race that defines ultra running.
CTL, ATL, TSB — the three lines on your Performance chart look intimidating, but they're the most useful numbers in HARDN. Here's what they mean, what good numbers look like, and the one thing most runners get wrong.
The entire endurance technology industry is obsessed with getting you to the starting line. The moment you actually need help the most, you’re on your own.
Most ultra runners obsess over training plans, gear lists, and nutrition strategies. And they should. But there's an entire half of race execution that gets almost zero attention from the tech world: crewing.
Most training apps assume you just started training. You haven't. When you set your training start date in HARDN, everything changes — your plan, your progress, your HARDN Score, and your AI Coach all reflect the work you've already done.