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If you’re someone who loves endurance activities—running, cycling, swimming—but also wants the benefits of resistance training, you’ve probably come across the concept of “concurrent training.” Simply put, it means combining aerobic and strength training within the same overall program. Despite the clear advantages of having both endurance and muscular strength, many athletes worry that mixing the two will sabotage their gains on one side or the other.
A 2016 study published in the European Journal of Applied Physiology (PubMed ID: 26730141) sheds light on the science behind this interplay. Let’s break down what the researchers found and how it applies to those of us looking to excel as hybrid athletes—no matter if your “endurance” of choice is a 5K, a marathon, or a weekend bike race.
Background: Why Concurrent Training Matters
Concurrent (or hybrid) training has become a hot topic because many endurance athletes are starting to realize the benefits of weightlifting, while many strength athletes see the value of better conditioning. It’s basically the best of both worlds—if done right.
Endurance Benefits: Increased cardiovascular capacity, greater efficiency at using oxygen (VO₂ max improvements), and better metabolic health.
Strength Benefits: Enhanced bone density, tendon/ligament health, injury prevention, and more powerful muscle contractions.
But here’s the classic concern: The “interference effect,” which suggests that heavy endurance training might blunt strength gains, and intense strength training might reduce endurance performance, especially if the volume is high or the workouts are poorly spaced. Researchers have been digging into how and why this happens—and what to do about it.
The Study at a Glance (PubMed ID: 26730141)
While the original paper goes into scientific detail, here’s the core of what you need to know:
Purpose: The researchers investigated the molecular and physiological responses when participants performed both endurance and resistance exercises. They wanted to see how the body adapts at the muscle level—looking at the cellular signaling pathways that govern muscle growth (hypertrophy) and endurance capacity.
Methods & Measurements:
Participants typically performed a combination of endurance (cycling, running intervals) and resistance sessions (e.g., squats, leg presses) in some form of structured weekly schedule.
The study tracked muscle protein synthesis, markers of mitochondrial biogenesis (the process by which cells build more energy-producing structures), and performance metrics like 1RM strength or VO₂ max tests.
Key Findings:
Molecular Overlap Isn’t Always a Bad Thing: Certain signaling pathways for endurance (such as increased AMPK and PGC-1α activity) can coexist with muscle-building signals (mTOR pathway) without necessarily canceling each other out—provided the training is programmed correctly.
Timing and Intensity Are Critical: High-intensity endurance sessions closely followed by high-intensity strength sessions can lead to acute “interference,” but the effect can be minimized if you manage rest intervals and schedule logically.
Adaptation Is Highly Individualized: Some participants showed minimal interference, especially those who spaced sessions out or used moderate volumes.
In a nutshell, the study reinforces that with proper programming, concurrent training can yield robust gains in both endurance and strength—and the dreaded interference effect isn’t as large or inevitable as once feared.
Connecting the Dots: How This Helps Hybrid Athletes
Strategic Scheduling Really Matters: The study’s findings emphasize that when you do each workout can significantly impact your results. If you do a grueling long run and then immediately smash your legs with heavy squats, you might not get the best from either session. Instead, consider:
Separating High-Intensity Workouts by 24 Hours: Let your body recover from the first session before you hit it again with a different stress.
“Easier” Endurance After Heavy Lifting (or vice versa): Keep the big demanding sessions from piling up on back-to-back days, or at least do them morning/evening with some recovery window.
Volume Control: Quality Over Quantity: One major takeaway is that jamming tons of mileage (or super-long endurance sessions) alongside high-volume strength training is a recipe for burnout. The molecular signals for muscle adaptation can get drowned out if you’re in a constant state of depletion from too much volume. On the flip side, excessive heavy lifting might leave you too fatigued to maintain quality endurance sessions.
Aim for “Minimum Effective Dose”: For endurance athletes, that might mean two focused strength sessions per week. For strength-first folks adding cardio, it might be two to three moderate-intensity interval sessions. You don’t need marathon-level mileage if your primary goal is overall fitness or performance in shorter events.
Energy and Nutrient Availability: Another subtle factor that came up in the broader literature (and hinted at in this study) is that if you’re under-eating while trying to do both strength and endurance training, adaptation can suffer across the board. Carbs fuel your endurance efforts, and adequate protein is necessary for muscle repair.
Tip: Consuming a blend of protein and carbohydrates within 30–60 minutes after exercise can help support muscle protein synthesis and replenish glycogen stores, keeping you ready for the next session.
Individual Response: Experiment and Track The study and others like it consistently note that individual differences matter. Some people adapt like champs, doubling up on workouts with no issues. Others feel wiped out after one moderate run plus a lifting session.
Keep a Simple Training Journal: Track not just sets, reps, and mile splits, but also how you feel the next day—energy levels, muscle soreness, mental focus. Over time, you’ll see patterns and can adjust accordingly.
Building a “Concurrent-Friendly” Weekly Plan
Putting theory into action, here’s a sample approach. Adjust it to your event schedule and personal recovery needs:
Monday: Strength (Lower Body Focus)
Squats (3×5 at moderate-to-heavy load)
Accessory work: Romanian deadlifts, lunges, core work
Finish with an optional short, easy walk or spin for active recovery
Tuesday: Interval or Tempo Run
5–10 minutes of dynamic warm-up
Main set: 3–6 x 800m at threshold pace or hill repeats
Cool down with easy jog
Wednesday: Off or Active Recovery
Light yoga, stretching, or easy swim
Thursday: Strength (Upper Body & Posterior Chain)
Deadlifts (3×5)
Push presses or bench press (3×5)
Accessory back/shoulder exercises (pull-ups, rows)
Friday: Moderate Endurance
45–60 minutes at an easy-to-moderate pace (Zone 2 or 3), focusing on consistent form
Saturday: Long Endurance Day
Long run or long ride, depending on your sport focus
Sunday: Off or Gentle Cross-Training
Easy bike ride, gentle swim, or complete rest
Notice how we place heavy lower-body lifting at least one day before an intense interval run. This avoids piling up intense leg stress back-to-back. Also, the long endurance effort is separated from the heavy lifts by at least a day.
Common Pitfalls & How to Avoid Them
Doing All High-Intensity, All the Time If every run is threshold or VO₂ max intervals, and every lifting session is max-effort squats or deadlifts, you’re practically begging for fatigue and injury. Make sure at least 80% of your endurance training is at or below moderate intensity (often referred to as the 80/20 rule in endurance training).
Ignoring Sleep and Nutrition The best training plan in the world won’t help if you’re sleeping five hours a night and under-eating by 500+ calories daily. Adequate rest supports the molecular adaptations that the study discusses (muscle protein synthesis, mitochondrial biogenesis, etc.).
Skipping the Gradual Approach If you’ve never done squats before, jumping straight into a 5×5 heavy squat program plus your usual 50-mile running week is a recipe for aches and pains. Incorporate new exercises or additional sets gradually, giving your body time to adapt.
What This Means for You:
Key Takeaways
Evidence-Based Reality: The 2016 study (PubMed ID: 26730141) supports the idea that you can develop both strength and endurance simultaneously—provided you manage volume, intensity, and recovery.
Programming & Timing Are Crucial: Spacing intense sessions and balancing overall workload helps avoid the interference effect.
Individual Differences Abound: Track your own progress, experiment with what works, and don’t assume a “one-size-fits-all” approach.
Long-Term Benefits: If done correctly, concurrent training can yield better body composition, higher power output, improved aerobic capacity, and reduced injury risk, making you a more robust, well-rounded athlete.
Final Thoughts: Embrace the Power of “Both/And”
You don’t have to be a pure endurance junkie who fears the squat rack, nor do you have to be a barbell purist who dreads the idea of lacing up running shoes. The real trick is recognizing that endurance training and resistance work each bring unique benefits to the table—and modern research (like the study from 2016) continues to bust the myth that one automatically destroys the other.
So, try out a simple, balanced schedule. Start with moderate volume, keep an eye on how you feel, and ramp up slowly. Listen to your body’s feedback: if you’re constantly exhausted, reduce volume or intensity in one domain. If you’re feeling strong and fresh, try edging up the load or the mileage in small increments. Over time, you’ll develop a training blueprint that lets you enjoy the full range of athletic performance—heart-lung stamina and muscular might—without burning out.
Bottom line? Hybrid athletes can indeed thrive on a steady diet of both endurance sessions and strength workouts. The science says it’s possible, your body craves the variety, and your long-term performance—and health—will thank you.
References & Further Reading
Study Reference: Concurrent Training Research (PubMed: 26730141)
General Guidance: American College of Sports Medicine (ACSM) Position Stands on aerobic and resistance training.
Scheduling Concepts: “Consolidation of Stressors” approach, popularized by various strength & conditioning coaches.
Additional Studies: Reviews in Sports Medicine and Journal of Strength and Conditioning Research on concurrent training adaptations.
Written by Chris Gilbert
Owner & Head Coach, TNT Fitness
NCCPT | Nutritionist | Tactical Conditioning Specialist
Helping individuals achieve purpose-driven fitness for life & performance.
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