Our Favorite In-Season Training Protocol For Mountain & Trail Athletes

Summer in Montana means long days on the trails for runners, hikers, and bikers. With race season in full swing, it’s tempting to devote every spare hour to logging miles or rides and shelve the gym work. But skipping strength training in the summer (or any in-season period) is a big and unfortunately common mistake. Maintaining a dose of strength work year-round will make you a more resilient, higher-performing mountain athlete. 

In this article, we’ll explore why strength training is crucial even during peak season, how the Eustress training approach (from Jon Pope and Craig Weller’s Building the Elite designed for elite Special Forces Operators) can deliver productive stress without burnout, and what the science says about the benefits of in-season resistance training for endurance athletes. We’ll also draw parallels to the phenomenal work capacity of Special Forces and elite athletes – and how you can build similar all-terrain athleticism.

The Summer Temptation: Why Endurance Athletes Drop Strength

After a winter of lifting and base building, many trail runners and mountain bikers abandon the weight room when summer adventures call. It’s understandable – who wants to be indoors when you could be summiting peaks or ripping singletrack? 

Additionally, athletes often worry that strength workouts will leave them sore or fatigued, interfering with key runs or rides. The result: strength training gets placed on the back burner until the off-season. However, cutting out strength completely for months can backfire. Research on endurance athletes has shown that when they stop resistance training during the competitive season, they rapidly lose the gains they worked so hard to build. In one study on elite cyclists, terminating strength workouts led to a “rapid decline of adaptations” – hard-earned strength and power faded within just 8 weeks of stopping lifting.

In contrast, those who kept a minimal strength routine in-season preserved their muscle size and strength and continued to improve performance. For example, well-trained cyclists who maintained one strength session per week during competition season kept the increases in thigh muscle cross-sectional area and leg strength they gained in the off-season, and even boosted their cycling power output and endurance more than the cyclists who did no strength training. 

In short, if you drop strength completely, you’re likely to give up hard-won benefits – and your performance and injury resilience can and will suffer.

Eustress Training: Productive Stress Without Burnout

How can you continue strength training in-season without overtaxing yourself? Enter Eustress training, a concept from Building the Elite’s Jon Pope and Craig Weller that provides just the right amount of stress. Eustress means positive, productive stress – the opposite of distress. 

In training terms, eustress workouts challenge you enough to elicit positive adaptations such as maintaining muscle mass, tissue integrity, and bone density, but not so much that they fry your nervous system or require days of recovery. 

According to coach Craig Weller (a former Special Forces operator) and Jon Pope, “Eustress training is a way of training your body to do more work, easily by raising the baseline of exercise you can handle without stressing your body out or draining your recovery capacity.” 

In practical terms, you’re teaching your body and mind that hard work can feel surprisingly manageable. Eustress training lets you train harder and recover faster. By staying below your max stress threshold, you accumulate relatively high volume at moderately heavy loads without triggering excessive fatigue. Over time, you can eventually push harder, recover faster, and when you want to really increase effort in the gym or on the trail, you have a higher output potential. Because you’ve practiced making tough efforts feel easy, you can do more before hitting your limit. 

In essence, eustress workouts build a bigger engine without burning it out. Importantly, Eustress-style strength work is designed for control and efficiency. Key characteristics include:

• Sub-maximal intensity, moderate to low volume: Lifting a weight that is challenging but not maximal, for moderate total reps over time. This builds work capacity. For example, you might perform 20–50 total reps of a lift in short mini-sets (1-3 reps at a time) with brief rest, staying in a comfortable heart rate zone. This approach packs in volume without spiking stress hormones.
• No form breakdown or grinding: Every rep is done with perfect technique; you stop well before failure. Quality of movement stays high even as fatigue slowly accumulates. This “teaches you how to make hard things easy” by refining technique and remaining mentally calm.
• Controlled heart rate and calm mind: Eustress sessions emphasize keeping your heart rate relatively low (e.g. <150 bpm) and actively managing your stress response. You rest just enough to let your heart rate drop and maintain composure between sets. The idea is to lift in a relaxed state, not a fight-or-flight frenzy.
• Short recovery and minimal soreness: Because you never go to all-out failure or trigger extreme fatigue, recovery time is short. You’re ready to train again sooner, which is ideal in-season when you also have high mileage or ride volume. Eustress strength work won’t leave you hobbling for days.

In practice, Eustress training is perfect for in-season strength maintenance. Pope notes that they often use eustress methods during high-volume “in-season” blocks, because it’s “high enough in intensity to maintain top-end output, but ‘feels’ easy enough to not be mentally stressful when volume is kept low.” 

It reinforces your ability to stay relaxed under effort – a skill that can decline when you’re grinding out long, intense days. For mountain athletes putting in big miles, this is gold. You can pair eustress lifting with “self-limiting and movement-restorative exercises” during your season (think controlled single-leg squats, lunges, core work, etc.) to shore up any movement issues and maintain proper range of motion while still respecting the heavy training load you’re carrying elsewhere. 

The bottom line: Eustress-style strength training lets you reap the benefits of lifting without derailing your endurance training.

Eustress training in action – performing moderately heavy deadlifts calmly for multiple sets. This approach builds strength and work capacity while keeping the effort feeling controlled, not crushing.

Why In-Season Strength Training Benefits Mountain Athletes

Limiting resistance training to shoulder seasons is a poor choice for athletes of any level; it directly supports your performance and health as an endurance athlete. Here are the key reasons you should keep lifting even in peak trail season, backed by science and experience:

1. Preserve Muscle Mass and Joint Tissue Quality

Endurance training by nature is catabolic – long runs/rides and high mileage weeks can break down muscle tissue and strain joints and tendons over time. Without any strength stimulus to counterbalance that, you risk gradually losing muscle mass and structural strength. Strength training is essential to reduce the loss of muscle mass, preserve joint health, and maintain peak performance, as noted in one training review. Even a relatively low dose of lifting can send an anabolic signals to your body that helps offset muscle breakdown. 

Crucially, strength work strengthens more than just muscles – it fortifies your connective tissues, bones, and cartilage by subjecting them to safe, controlled loads. It is, by definition, a preventive measure for your body against breaking down. Research shows resistance exercise increases bone density and connective tissue resilience, which running and cycling (or bodyweight workouts) alone does not address. Many endurance athletes actually have low bone density or weak supporting musculature from neglecting weights; over the long term this can lead to stress fractures or joint degeneration. By keeping a weekly strength routine, you maintain the integrity of your joints and tissues during the pounding summer months. Think of it as keeping the chassis of your “vehicle” strong while the engine logs high mileage.

2. Injury Prevention and Durability

Mountain sports are tough on the body – steep descents, uneven terrain, and repetitive motion can create or exacerbate imbalances. One of the biggest arguments for in-season strength training is injury prevention. Endurance athletes are prone to overuse injuries (IT band syndrome, anterior knee pain, Achilles issues, plantar fasciitis, etc.), especially when ramping up volume. Strength training serves as a protective armor: it corrects muscle imbalances, improves joint stability, and builds resilience in tissues so they can withstand higher training loads. 

For instance, strengthening the glutes, hips, and core can improve your alignment and form on the trail, reducing stress on knees and ankles. Exercises like single-leg squats or deadlifts with good posture train the muscles both in your lower body and in your core that keep you balanced on technical terrain. Stronger leg and core muscles also mean each stride or pedal stroke places less strain on passive structures like ligaments and is more efficient. 

Studies on runners have found that incorporating strength training significantly lowers injury rates compared to those who only do their aerobic work. Simply put, maintaining strength work keeps your body durable so you’re less likely to be sidelined mid-season. 

An added bonus: if you do take a spill or have a mishap, a stronger body can better absorb impact and recover faster. Furthermore, avoiding the PT in the late summer or fall means more time for play and a better ability to shift to winter sports.

3. Enhanced Performance: Running Economy, Power, and Endurance

Contrary to the popular fear that lifting might “slow you down,” smart strength training and plyometrics will actually make you faster and improve your endurance. Extensive research in endurance sport athletes has confirmed that adding resistance training leads to better performance metrics. 

For runners, one of the key measures is running economy – how efficiently you use oxygen at a given pace. Multiple studies and reviews have shown that strength training improves running economy in mid- and long-distance runners, meaning you become more energy-efficient. With stronger muscles and tendons, each stride is more forceful and elastic, so you maintain pace with less effort. One review in Sports Medicine summed it up: strength work is a significant variable for boosting running efficiency. It’s not just runners – cyclists and skiers see similar benefits in power output and fatigue resistance from weight training. 

Importantly, these gains come without adding bulk or hurting your VO₂ max. In fact, a well-designed strength program (focusing on low-rep heavy lifts and explosive moves) tends to improve neuromuscular coordination, not muscle size. Training to gain muscle (Hypertrophy) and training for pure strength are quite different. For example, in one study, a group of athletes who dedicated a portion of training to heavy strength and plyometrics improved their 5K times, increased their anaerobic capacity, and saw better endurance with no loss of aerobic capacity compared to a control group. Stronger legs also translate to higher peak power on the bike and more sprint reserve at the end of a long effort. 

Don’t forget uphill performance – those hill climbs get easier when you’ve built up your glutes, quads, and calves in the weight room. Think of strength training as raising your performance ceiling: you develop a bigger power engine to complement your endurance fuel tank.

4. Faster Recovery and Sustainable Volume

One paradoxical effect of keeping up with strength work: it can actually help you better handle your endurance training. Regular resistance training (especially using a eustress approach) conditions your body to tolerate and recover from training stress. This is called Work Capacity. 

By exposing yourself to manageable levels of lifting stress, you stimulate your recovery systems and hormonal responses in a beneficial way. Eustress training in particular reduces recovery time – allowing you to shift emphasis to other physiological demands. Athletes who build a higher work capacity through strength can often bounce back quicker between hard workouts. 

Ever notice how some ultra-endurance racers seem almost invincible, able to crank out long run after long run? Often, they have a history of strength or power training that gives them a wider base of fitness. Their bodies don’t view a 4-hour effort as a total emergency because they’ve done hard but controlled work in training (like heavy carries, circuits, etc.). Strength training increases your overall work capacity and fatigue resistance, so big days take less out of you. 

In mountain terms, if you strengthen your legs and core, a 5-10k ft. day won’t trash you as much – you’ll recover faster for the next day’s adventure. This means you can sustain higher volumes in-season without breaking down. It’s no surprise that many coaches of elite endurance athletes keep some lifting year-round precisely to help with recovery and to avoid the “fragility” that can come from only doing one type of exercise.

NBA players now famously do resistance training after games to help with regulation during a packed in-season for this very reason.

Elite Models of Resilience: Special Ops and All-Terrain Athletes

Need more proof that balancing strength and endurance is the recipe for peak performance? Just look at the training of Special Forces operators and other elite tactical athletes. These individuals are the epitome of all-around fitness: they can ruck mountains with heavy packs, sprint or fight when needed, and keep going for hours or days. How do they develop such high-level work capacity and resiliency? One key is that they train strength and endurance concurrently, year-round – they have to, because their missions demand both. 

In fact, the Eustress training concept itself was born from special operations preparation. Craig Weller developed it after seeing how controlling the stress response allowed him and his teammates to do more work with less wear-and-tear. Special Ops training programs incorporate athlete style training (Plyos, contrast training) with strength circuits, heavy carries, and bodyweight exercises even during intense endurance phases. This builds what Jon Pope calls a “high tolerance for objectively difficult conditions without a strong stress response.” 

In other words, make hard things feel easier – exactly what mountain athletes want when facing a grueling climb at mile 30 of an ultra or a long backcountry expedition. 

The example set by these tactical athletes and ultra-endurance elites is clear: true fitness means being adaptable. As a mountain runner or biker, you aren’t served by being one-dimensional. Sure, you could drop strength training and just run or ride more – you might eke out a slight endurance gain in the very short term, but you risk becoming less robust overall. 

Instead, strive to be like those elite performers who can do it all. Maintaining some strength work will give you that extra gear and resilience. You’ll handle surprise demands (like carrying a buddy’s bike out of the woods, or scrambling up a boulder field) without issue. And you’ll simply feel better – stronger, safer, and more confident in your body’s capabilities.

Long-Term Athleticism and Adaptability

Finally, think beyond this season. The benefits of in-season strength training compound over time. By committing to year-round strength, you are investing in your long-term athleticism. Season after season, you’ll build upon a solid foundation instead of starting from scratch each off-season. This leads to cumulative improvements in power, efficiency, and injury resistance. 

Many masters athletes who remain competitive well into their 50s or 60s cite consistent strength training as a key factor that keeps them young in sport. It’s not just about performance in one race, but maintaining the ability to do what you love – trail running, mountain biking, skiing, climbing – for decades without your body breaking down. 

Strength training fortifies your muscles and joints against Father Time. Moreover, keeping a bit of strength work in your routine can rekindle motivation and break the monotony of pure endurance training. It’s mentally refreshing to challenge your body in a different way, and the confidence from hitting some weights can carry over to your trail exploits. Instead of viewing gym sessions as a shoulder season chore, see them as an integral part of being an athlete year-round. 

Embrace the identity of a well-rounded mountain athlete – one who can run far, ride long, and lift strong. That approach will pay dividends, not just during summer race season, but whenever new challenges arise.

Conclusion: Stronger = Better (Even in Summer)

When the mountains are calling, absolutely get out and enjoy them – but don’t neglect the strength and stability work that allows you to answer that call at your best. By applying a Eustress training method and mindset, you can integrate strength training into your summer schedule in a way that compliments your running or riding, rather than competing with it. 

The science is clear and convincing: as little as one heavy, low volume, and efficient strength training session each week can keep your gains, prevent losses, boost your performance, protect you from injury, and build the kind of resilient fitness that sets you apart. 

As we’ve discussed, studies are clear that just 1–2 focused strength sessions per week (think 30–45 minutes of compound lifts and mobility) can make a huge difference. Remember, this means external load. Unfortunately, bodyweight, reformer, etc, workouts don’t count in this instance. 

So, as you lace up for that next trail run or prep your bike for a big ride, remember the weight room is your friend, not foe. Don’t fall for the allure of just running or biking all summer. Strong legs, a stable core, addressing full range-of-motion, and the capacity to handle stress will make you a faster, safer, and happier mountain athlete. Train smart with productive eustress, and you’ll find that a bit of lifting actually gives you more energy for those epic days outside. 

In the end, strength training isn’t a distraction from your sport – it’s a secret weapon for longevity and success in it. Keep the iron in your in-season diet, and enjoy the rewards on every trail and summit you conquer.