The Trail Running Briefing

In this episode, we cover why carb loading is not about eating a huge bowl of pasta the night before a race, but about arriving at the start line with full fuel stores. For trail and ultra runners, glycogen is the body’s fast-access fuel, and starting underfuelled can make the later stages of a race much harder. The key message is simple: carb loading should be planned, practised, and spread acros...

In this episode, we look at one of the most important skills in ultrarunning: managing the low points. Every runner will face dark moments during an ultra, but a low point is not necessarily the end of the race. It is usually information: you may need fuel, fluids, sodium, cooling, warmer clothing, slower pacing, or simply a mental reset. The key message is: do not make big decisions from a low po...

In this episode, we explain the difference between heat acclimatisation and heat acclimation. Acclimatisation usually refers to adapting naturally to a hot environment, while acclimation is a more controlled process using tools like hot-water immersion, sauna, or structured heat exposure. The key message is that heat adaptation is not just about “getting used to suffering.” It creates real physiol...

In this episode, we explore one of the most important principles for sustainable ultrarunning progress: using the minimum intensity needed to create the right adaptation . The goal of training is not to suffer as much as possible. The goal is to apply the right stimulus, recover from it, and repeat it consistently over time. Whether we are doing intervals, hill work, downhill sessions, strength tr...

Elite trail runners do not descend faster simply because they are braver. They descend faster because they brake less. Downhill running creates a lot of muscle damage because the quadriceps are working eccentrically: they produce force while lengthening to control the body against gravity. Every downhill step is like a small controlled landing. When runners overstride, lean back, tense up, and lan...

Caffeine is one of the most evidence-supported supplements for endurance performance, but ultrarunners need to use it strategically rather than simply taking more. The key message is that caffeine is not fuel. Carbohydrates provide energy for the muscles; caffeine mainly helps with alertness, focus, motivation, and perceived effort. This makes it especially useful in long ultras, where mental fati...

In this episode, we explore why many trail and ultra runners feel that their breathing is still under control, but their legs simply stop working. The main idea is that ultra running is not limited only by cardiovascular fitness. It is also limited by local muscular endurance : the ability of the quads, calves, glutes and stabilising muscles to keep producing force for hours. Climbing, descending...

This episode explains why running performance drops in hot conditions and why it is not simply a loss of fitness or lack of toughness. In the heat, the body has two jobs: keep running and protect itself from overheating. More blood is directed towards the skin for cooling, sweat rate increases, heart rate rises, and the same pace costs more energy. The key message is that on hot days, effort matte...

In this episode of The Trail Running Briefing , we explore why choosing a race with purpose can be a powerful part of ultra-distance performance. Training, pacing, fuelling, strength, and recovery all matter, but when a race becomes difficult, runners also need a strong reason to keep moving. Purpose gives suffering direction. It helps runners stay patient, calm, and committed when fatigue, bad we...

This episode explains why recovery is one of the biggest limiting factors in ultrarunning performance. The key idea is that training does not create fitness by itself, training creates stress, and recovery allows the body to adapt. The episode challenges the common mistake of treating recovery as something you can buy or add at the end, such as massage, compression boots, red light therapy, or oth...

Tapering is not about resting, it’s about absorbing the training you’ve already done . After weeks or months of building fatigue through long runs and hard sessions, your body needs time to recover and convert that work into performance. Without a proper taper, you arrive at the start line carrying fatigue instead of fitness. The goal of tapering is simple: reduce fatigue while maintaining fitness...

Hydration in long trail running is not just about drinking water. It is about replacing enough fluid and sodium to stay functional as conditions, duration, and sweat losses increase. This episode explains why runners can drink plenty and still feel flat, thirsty, heavy, or cramp-prone when sodium intake does not match the demands of the session. It also unpacks the simple idea that water replaces...

HRV, or heart rate variability, is not a score that tells ultrarunners whether they are fit or unfit on a given day. It is a signal of how well the body is handling overall stress. That stress comes not only from training, but also from sleep, work, travel, fuelling, illness, and life outside running. The key idea in the episode is that HRV is most useful when viewed as a trend , not as a single d...

Training fatigue is normal. Overtraining is not. And very often, what runners call “overtraining” is actually a mix of excessive load, poor recovery, and under-fuelling. This episode explains the difference between normal fatigue, non-functional overreaching, true overtraining syndrome, and Relative Energy Deficiency in Sport, or RED-S. The key message is that not all fatigue is the same, and the...

Training hard has its place, but harder is not always better. In this episode, we explore why the real value of a session is not just in the stimulus it provides, but in the recovery cost it creates. For trail and ultra runners, going too hard too often can quietly reduce consistency, compromise quality, increase injury risk, and leave you too fatigued to absorb the training that actually matters....

Downhill running is one of the most damaging parts of trail racing, not because it is aerobicly hard, but because it places heavy eccentric load on the muscles, especially the quads. In this episode, we explain why downhill running creates so much soreness and fatigue, and why the solution is not to avoid it, but to train it progressively. The key idea is that downhill training should be treated l...

In this episode of The Trail Running Briefing , we explore one of the most important but misunderstood ideas in endurance training: you often run faster by slowing down more often . Many runners make the mistake of pushing too hard on easy days, turning most of their training into moderate effort and limiting recovery, consistency, and performance. This episode explains why truly easy running is e...

In this episode of The Trail Running Briefing , we unpack why Zone 3 is one of the most misunderstood training intensities in endurance sport . Often dismissed as “junk miles” or the “grey zone,” Zone 3 is frequently criticised simply because many runners use it by accident rather than with a clear purpose. This episode explains why that view is too simplistic, especially for trail runners and mas...

This episode explains fuel utilisation in simple terms: your body is always using a mix of fat and carbohydrate , but the harder you run, the more you rely on carbs . The key message is that many runners don’t “blow up” because they forgot to eat, they blow up because their pace created a higher carbohydrate demand than their fueling plan could support. The episode uses a simple mental model of tw...

In this episode, we unpack why lactate threshold is one of the most useful predictors of ultra performance, not because you race at threshold, but because it sets the ceiling for what “sustainable” feels like for hours. A higher threshold means your steady effort costs less energy, surges hurt less, and you drift into the red less often on climbs, headwinds, heat, and technical sections. You’ll le...

Motivation is a mood, it comes and goes. Consistency is a system, it keeps you training even when life gets messy. This episode explains why relying on “feeling like it” leads to stop-start training, and why the runners who improve most are the ones who reduce friction, pre-decide their sessions, and protect a minimum standard on low-energy days. You’ll learn practical tools like a “minimum viable...

VO₂max measures your maximum aerobic capacity, but ultra races are not performed anywhere near that intensity. What decides performance is not how big your “engine” is, but how efficiently and sustainably you can use it for many hours. Ultra success depends on factors like lactate threshold, aerobic efficiency, fueling tolerance, muscular durability (especially for long descents), and disciplined...

Intensity can drive quick improvements in trail running performance but only for a short time. Hard sessions create a strong training signal, yet they also generate fatigue faster than they build fitness. At first, fitness gains are visible; over time, accumulated fatigue masks those gains, leaving runners feeling heavy, flat, and slower despite training harder. The mistake many runners make is re...

Most ultra runners don’t lose races on the climbs—they lose them on the descents. In this episode of The Trail Running Briefing , we break down why downhill running causes so much damage despite feeling easy at the time. You’ll learn how eccentric muscle loading silently destroys the quads, why this fatigue is delayed and deceptive, and why cardiovascular fitness alone won’t protect you late in an...

This episode explores a common frustration among runners: increasing training volume or intensity, yet feeling slower, heavier, and less fit. The key message is simple, fitness doesn’t come from training itself, but from recovering from training . Using a clear mental model, the episode explains how training creates fatigue, and recovery is what allows adaptation and improvement. When training loa...