Harsh-environment journey: ultra, altitude and cold exposure

Both plans are paid, coach-written products with 5 runs a week, 2 rest days and effort-based (RPE) pacing, no speed work apart from Tuesday strides Sunrise Run Co. 50 mile plan Sunrise Run Co. 100 mile plan. They are common coaching practice, not tested in trials. Each plan costs $39.99 Sunrise Run Co. plan list.

Sources: Sunrise Run Co. 50 mile plan, Sunrise Run Co. 100 mile plan

• 21-54 miweekly range of the 50K plan, 24 weeksSunrise Run Co. plan list
• 30-84 miweekly range of the 100 mile planSunrise Run Co. plan list
• 55-62 miweekly mileage the 100 mile plan expects before week 1Sunrise Run Co. 100 mile plan
• 4220-minute strength sessions in the 100 mile plan, plus 24 mobility sessionsSunrise Run Co. 100 mile plan

Vertical gain: the plan pages publish no climbing targets. They only advise power hiking climbs on the peak weekends Sunrise Run Co. 100 mile plan. Do not invent a weekly vert number from this; match your long runs to the climb of your goal course.

Sources: Sunrise Run Co. 50 mile plan, Sunrise Run Co. 100 mile plan

The 100 mile weekend pair is 30 plus 22, so 52 miles in two days. Weekend long runs begin in week 1 (20 and 12 miles, 32 total) and grow from there Sunrise Run Co. 100 mile plan. On the 100 mile plan the Sunday run becomes optional in the week-19 dress rehearsal and shrinks to 5 miles in taper Sunrise Run Co. 100 mile plan.

Sources: ISSN ultra position stand 2019, Jeukendrup, GSSI SSE 108

• Sodium per hour above is 0.45 L x 500 mg/L = 225 mg up to 0.75 L x 700 mg/L = 525 mg, our arithmetic from the ISSN ranges; the stand's heat figure is 300-600 mg/h ISSN ultra position stand 2019.
• Practice the plan in training: the ISSN stand recommends progressive gut training, and commercial products may not supply enough sodium in heat ISSN ultra position stand 2019.
• Weigh before and after long runs to estimate your sweat rate; ACSM calls for individual plans and aims to keep body water loss under 2% ACSM fluid stand 2007.
• Avoid excessive plain water; exercise-associated hyponatremia is serum sodium under 135 mmol/L and is potentially fatal ISSN ultra position stand 2019.

• 375-600 gcarbohydrate a day at 5-8 g/kg, 75 kg runner (arithmetic)ISSN ultra position stand 2019
• 120 gprotein a day at 1.6 g/kg, 75 kg runner (arithmetic)ISSN ultra position stand 2019
• 187.5 gprotein a day at the 2.5 g/kg ceiling for demanding phasesISSN ultra position stand 2019

Cost of 120 g protein using this site's US data, read 2026-10-26: eggs at Kroger.com are about $1.65 per 100 g of protein (18 eggs, $1.78), so $1.98 for the day from eggs alone, and dry brown lentils at $1.87 per 100 g are $2.25. These are single-food illustrations of the cheapest rows in the data, not a menu.

Sources: Running Warehouse Speedgoat 7, Ultimate Direction vest page, Petzl ACTIK CORE page, Black Diamond poles page

Layers and shell: no wind jacket or insulation price could be confirmed this session, so none is listed. A second pair of shoes would bring the list to $812.75 (our arithmetic: 647.80 + 164.95).

Sources: Western States entry page, Western States qualifying races, Leadville Trail 100 Run page, Leadville lottery and qualification

The Western States refund schedule (excluding the online fee) is 75% back by May 1 ($431.25), 50% from May 2 to June 9 ($287.50), 25% from June 10 to June 20 ($143.75), then nothing Western States entry page. The entry page does not state a 100K qualifying time, so check the race's own rules Western States qualifying races.

Sources: Sunrise Run Co. plan list, Ultimate Direction vest page, Leadville Trail 100 Run page, Western States entry page

In the 1998 trial, 8 volunteers did 3-minute head-out immersions in 10 C water; their breathing rate fell to 79% of the first response, while 7 controls without repeat exposure fell to 91% Tipton 1998. That study tested habituation to the gasp response, not training benefit or recovery.

Sources: Tipton 1998, Outdoor Swimming Society

• Below 15 C unacclimatised swimmers are at risk from cold shock; do not dive or jump in Outdoor Swimming Society.
• Finger-to-thumb test: if you cannot touch your second fingertip to your thumb, you have cold incapacitation; get out Outdoor Swimming Society.
• Expect to feel colder about 10 minutes after leaving the water Outdoor Swimming Society. Stay near shore and have warm clothes ready.
• Cold dips right after lifting reduced strength and muscle gain in a 12-week trial of 21 men, so keep them away from strength days Roberts 2015.

Sources: AAFP summary of WMS hypothermia guideline 2020

Sources: AAFP summary of WMS altitude guideline 2020

• Above 9,800 ft (3,000 m), raise sleeping altitude by no more than 1,600 ft (500 m) a night and take a rest day after every 3,300 ft (1,000 m) gained AAFP summary of WMS altitude guideline 2020.
• Staged ascent: spend 6 to 7 days at 7,200 to 9,800 ft before going higher AAFP summary of WMS altitude guideline 2020.
• Acetazolamide for prevention is 125 mg every 12 hours for adults, started the day before ascent; it is contraindicated after anaphylaxis or Stevens-Johnson syndrome from a sulfonamide AAFP summary of WMS altitude guideline 2020. Ask a clinician; this is not a recommendation to self-prescribe.

• Day 1: log your last four weeks of mileage. The 50 mile plan expects 36 to 42 miles a week, 5 days, a 14 mile long run and a 6 to 9 mile run Sunrise Run Co. 50 mile plan.
• Day 2: pick the goal race and read its fee, cutoff and qualifier rules (Leadville 30 h, $495; Western States $575) Leadville Trail 100 Run page Western States entry page.
• Day 3: buy shoes and vest first ($164.95 and $174.95) and start running with them Running Warehouse Speedgoat 7 Ultimate Direction vest page.
• Day 4: weigh yourself before and after a one hour run to estimate sweat loss ACSM fluid stand 2007.
• Day 5: book two 20-minute strength and mobility sessions; the 100 mile plan has 42 Sunrise Run Co. 100 mile plan.
• Day 6: run the first Saturday long run and Sunday back-to-back (the 50 mile plan expects a 14 mile long run as an entry prerequisite; its week 1 totals 38 miles over 5 runs) Sunrise Run Co. 50 mile plan.
• Day 7: rest, then decide between the 50 mile and 100 mile build based on week 1 honestly.

Honest fit: 36% of runners dropped out of a 690 km Arctic ultra and 64.6% of 1,212 ultrarunners lost training days to injury in a year Schalt 2025 ULTRA study 2014. No screening questionnaire (PAR-Q+ or ACSM) was fetched this session, so see a clinician if you have heart or lung conditions, especially before altitude or cold-water work.

Two male runners in a 161 km mountain race (both finished in 32.8 hours) burned about 15,700 and 15,900 kcal by doubly labeled water and reported eating roughly half of it Creer 2025. The deficit figure is our arithmetic from that ratio, not a number the authors report.

Slower polar events show the same pattern over weeks. In an 800 km Antarctic race (13 competitors measured, mean age 40), carbohydrate supplied only 23.7% of energy and mean body mass fell 8.3 kg, of which 2.0 kg was lean mass Paulin 2015.

Sources: Creer 2025, Paulin 2015, Hattersley 2019

In the traverse men, lean tissue did not fall significantly (P = 0.18), and the authors suggest part of the weight loss reflects the energy cost of staying warm Hattersley 2019.

The largest cohort is 23,996 starters of the Two Oceans 56 km race across four years. Older age and female sex were linked to not finishing, as were fewer years of running, less race experience, lower weekly training distance, a race pace slower than training pace, and higher wet-bulb globe temperature SAFER XXI 2022.

The abstract gives P-values from univariate analyses and no odds ratios or overall finish rate, so it ranks risk factors without sizing them. A 56 km road race is also much easier than a 100-mile mountain event.

• 23,996starters analyzed over 4 years (56 km road race)SAFER XXI 2022
• 38%mean DNF across 25 hundred-mile races in 2023 (media analysis, average of race rates)iRunFar DNF analysis

The 38% figure comes from a trail-running site's limited sample and averages race rates, so it is not a pooled rate over starters iRunFar DNF analysis. The Yukon race figure already above (8 of 22) sits in the same range.

A meta-analysis of 13 studies pooled 17.8 injuries per 1,000 hours for novice runners and 7.7 for recreational runners. For ultramarathon runners, only one study reported a rate, 7.2 per 1,000 hours, with no confidence interval, so nothing could be pooled Videbaek 2015.

• Injury definitions differed, including time-loss thresholds from 1 day to 1 week Videbaek 2015.
• Many studies used self-reported running diaries, which adds recall bias Videbaek 2015.
• The page's yearly figure (64.6% injured over a year) and this per-hour figure measure different things and cannot be converted into each other.

A 2025 narrative review of 16 studies (10 quantitative) in athletes doing events of six hours or more found risk flags in large shares of every sample, while noting the evidence base is limited Colangelo 2025.

Sources: Colangelo 2025

The review's authors flag that bone stress injury reached 20.5% of men (n = 83) and 37.5% of women (n = 40) in one sample, and that the review itself contains internal numeric inconsistencies in its discussion Colangelo 2025. We used the figures from its results list.

An umbrella review of 15 meta-analyses covering 161 unique studies rated certainty low to very low. Soreness fell for up to 96 hours; strength showed no gain and strength and muscle-size gains were impaired with chronic use. Endurance performance rose immediately after immersion with no later benefit Berjisian 2026.

A second umbrella review of 14 reviews found the most consistent effect was on self-reported soreness (standardized differences -1.04 to -0.37), but the largest estimate was soccer-specific and its prediction interval crossed zero. Overlap among reviews was high, so they are not independent confirmations Liang 2026.

• 10 to 15 minmost-studied immersion time, at 10 to 15 °C or 5 to 10 °CBerjisian 2026
• 13 studiesin a meta-analysis of cold exposure and mood (4,105 adults), most at high risk of biasNgandeu Schepanski 2026

For mood, the pooled estimates leaned favorable with wide intervals and shrank in controlled-only analyses, so the authors say benefit is not established Ngandeu Schepanski 2026. The common temperatures are descriptive, not an optimized prescription Liang 2026.

A review of the Wim Hof Method found eight trials (nine papers) with about 194 participants in total, 86.4% male. Seven of eight RCTs had high concerns of bias and the authors rate overall quality as very low. Inflammatory markers fell in some trials, and exercise results were mixed Almahayni 2024.

Adverse events were poorly reported. In one study, 33% of participants using the breathing method reported deafness and heaviness; a trial in axial spondyloarthritis (19 analyzed, 8 weeks) found no difference in adverse events between groups Almahayni 2024.

• Cold plus breath-holding with the face wet can set off opposing heart reflexes; arrhythmias appeared in 62 to 82% of breath-hold submersions in young healthy volunteers, versus about 2% of free-breathing head-out immersions Shattock 2012.
• That link to deaths is a hypothesis; the authors say arrhythmic deaths cannot be confirmed after the fact Shattock 2012.
• Hyperventilation before a breath-hold submersion is part of the formal definition of hypoxic (shallow-water) blackout, which can happen in water under 5 m Bart StatPearls.

At altitude, a review of 12 observational studies (11,021 people, 2,200 to 4,559 m) found acute mountain sickness rose about 4.5 times more steeply with altitude after flying in than after hiking or mixed travel. Diagnosis criteria differed across studies Burtscher 2023.

None of these sources tested breathing or cold protocols as preparation for an ultra or expedition, so any such link is unproven.