Mastering Technical Descents in Ultramarathons: Protect Your Quads with the Repeated Bout Effect
“My quads are smashed”… Easily the most common comment I hear someone say after an ultra!
Queue a week-long period of standing at the top of your stairs each morning thinking “FFS!” before gingerly shuffling down said stairs, holding onto the handrail for dear life!
We’ve all been there!
For some more unfortunate folks, Rhabdomyolysis, a far more serious condition, can be the result… more on that later.
For some, the “quad smashing” takes place even in the event itself! You’ve probably had the delightful experience of shuffling painfully down a mountain in the latter stages of an ultra, so you know exactly what I mean. Thankfully, science gives us a powerful strategy called the Repeated Bout Effect (RBE) to make our quads “bulletproof” (because that’s what all the influencers say, right?) against those brutal descents.
What Exactly is the Repeated Bout Effect?
The Repeated Bout Effect is your muscles’ fantastic ability to “remember” past stress and adapt to protect themselves for future stresses. When you run downhill, your quads perform eccentric contractions (lengthening under load), crucial for absorbing shock but notorious for causing significant muscle damage, soreness, and fatigue. After enduring that initial soreness, however, your muscles become tougher and suffer less damage in subsequent descents. This resilience results from structural, neural, and cellular adaptations:
- Structural Adaptations: Stronger muscle fibers, reinforced connective tissues, and improved muscle resilience.
- Neural Adaptations: Enhanced muscle coordination and motor control, spreading workload evenly.
- Cellular Adaptations: Reduced inflammation and quicker muscle repair post-workout.
In other words, by strategically exposing your legs to downhill running, you dramatically reduce soreness and damage next time around. Emphasis on the word ‘strategically’—it’s not just about “doing loads of downhills,” a common but misguided piece of advice I frequently see in Facebook forums!
The Importance of Understanding Rhabdomyolysis
Before diving into how to leverage Repeated Bout Effect effectively, it’s crucial to talk about rhabdomyolysis—a severe condition resulting from excessive muscle breakdown. Rhabdomyolysis occurs when damaged muscle tissue releases proteins (myoglobin) into the bloodstream, potentially harming the kidneys and causing serious health issues. Symptoms to watch out for include:
- Severe muscle pain and swelling
- Weakness and fatigue
- Dark-coloured urine (similar to cola)
Rhabdomyolysis is rare but serious and usually results from extreme muscle damage due to excessively intense or prolonged eccentric exercise, such as aggressive downhill running without adequate preparation. Awareness and prevention are key: never push through intense muscle pain and always ensure proper progression and adequate recovery.
Detailed and Actionable Training Protocols to Leverage RBE
Here’s your in-depth, practical guide to incorporating Repeated Bout Effect effectively:
1. Optimal Frequency: Less is More
Aim to include dedicated downhill sessions every 2-3 weeks to sustain muscle adaptations without risking injury or overtraining. Key sessions should ideally be scheduled 3-5 weeks before your main race to peak eccentric strength and ensure adequate recovery time.
2. Progressive Overload: Structured Progression
Adopt a structured approach to gradually introduce downhill stress:
Weeks 1-4:
- Short downhill segments (5-10 mins), moderate slope (~4-6%), comfortable pace.
- Total weekly downhill duration: ~15-20 mins.
Weeks 5-8:
- Increase segment length (10-20 mins), slightly steeper gradients (6-10%), controlled pace.
- Total weekly downhill duration: ~25-30 mins.
Weeks 9-12:
- Longer downhill segments (20-30 mins), maintain moderate-steep gradients (8-12%), start introducing faster pace intervals.
- Total weekly downhill duration: ~30-40 mins.
Weeks 13-16 (Race-Specific):
- Peak downhill session: 1-2 long runs replicating race conditions (e.g., prolonged downhill stretches, race-specific gradients, controlled moderate-hard effort).
- Maintain downhill stimulus through taper, but reduce total duration/intensity significantly.
3. Integrating Downhills into Long Runs
Consistently incorporate deliberate downhill segments within weekly long runs:
- Run downhill sections with focused, steady effort rather than a leisurely jog.
- Example: During a 3-hour long run, include 2-3 deliberate downhill segments of 15-20 minutes each.
4. Specific Downhill Workouts (Every 2-3 Weeks)
- Downhill Tempo Runs: 20-30 mins continuous downhill at comfortably challenging effort.
- Downhill Interval Session: 3-5 repeats of 5-8 mins downhill running at higher intensity, easy uphill recovery jogs.
- Simulation Runs: Perform at least one session mimicking key descents of your target ultra, ideally 3-5 weeks before race day.
Warning Signs to Avoid Overdoing It
Monitor your body closely and adjust your training accordingly. Be alert for:
- Prolonged soreness exceeding three days.
- Persistent fatigue and declining performance.
- Joint or tendon discomfort, particularly knees or Achilles tendons.
- Symptoms of excessive muscle breakdown (severe muscle pain, dark urine, significant swelling)—signs indicating potential rhabdomyolysis.
Should you notice these, scale back, rest, hydrate adequately, and seek medical attention if symptoms persist or worsen.
Nutritional and Recovery Strategies for Optimal Adaptation
Support your downhill training adaptations with focused nutritional and recovery practices:
- Protein: Consume 1.6-2.2g/kg body weight daily to optimize muscle repair.
- Anti-inflammatory Foods: Include omega-3 rich sources (salmon, chia seeds, berries, leafy greens).
- Hydration and Electrolytes: Maintain balanced fluid and electrolyte intake, critical to muscular recovery.
- Active Recovery Protocols: Incorporate low-impact activities (walking, cycling), compression garments, mobility work, and, as ever, prioritise sleep!
Putting It All Together
The Repeated Bout Effect isn’t just science jargon—it’s your ticket to stronger legs, faster recovery, and more enjoyable racing experiences. As an N=1, I implement these very strategies myself and have found in my own racing to feel the protective effects of Repeated Bout Effect. Case in point is I felt incredible during the CCC by UTMB… my race was only derailed by other gut-related issues… but coming down into Trient, the 72km checkpoint, I felt strong and can give much of the credit for this to the Repeated Bout Effect protocols I had implemented. In fact, it also helped me recover quickly too, as I ran a 1:22 HM just a week later!
So, implement these detailed, practical strategies progressively and carefully, and you’ll confidently conquer downhill sections in your next ultra, rather than suffering painfully to the finish, and crying when you next see your staircase!
Happy trails,
Written by Nick Hancock
Head Coach and Founder of Maximum Mileage Coaching
References:
Bontemps B, Vercruyssen F, Gruet M, Louis J. Downhill Running: What Are The Effects and How Can We Adapt? A Narrative Review. Sports Med. 2020 Dec;50(12):2083-2110. doi: 10.1007/s40279-020-01355-z. PMID: 33037592; PMCID: PMC7674385.
Tallis J, McMorrow C, Shelley SP, Eustace SJ. Repeated Bout Effect of Downhill Running on Physiological Markers of Effort and Post Exercise Perception of Soreness in Trained Female Distance Runners. Sports (Basel). 2024 Jun 17;12(6):169. doi: 10.3390/sports12060169. PMID: 38921863; PMCID: PMC11209549.
Tallis J, McMorrow C, Shelley SP, Eustace SJ. Repeated Bout Effect of Downhill Running on Physiological Markers of Effort and Post Exercise Perception of Soreness in Trained Female Distance Runners. Sports (Basel). 2024 Jun 17;12(6):169. doi: 10.3390/sports12060169. PMID: 38921863; PMCID: PMC11209549.
