What did the first bodybuilding refeed study by Bill Campbell's lab find?

The study found non-significant differences in fat mass, fat-free mass, and resting metabolic rate between continuous dieting and a refeed group (5 days dieting, 2 days maintenance). However, the refeed group lost less 'dry fat-free mass' and had smaller reductions in RMR, suggesting refeeds may be beneficial for maintaining lean body mass.

How long do refeeds need to be to be effective?

The discussed study used two-day refeed periods. While the presenters joked about much longer 'refeeds' or diet breaks, the current research supports shorter, structured refeeds for modest benefits in lean mass preservation and metabolic rate during dieting.

What is the 'interference effect' in concurrent training?

The interference effect refers to the attenuation of strength and hypertrophy adaptations when long-duration aerobic exercise is combined with resistance training. However, studies demonstrating this often use extreme, unrealistic cardio volumes.

How can I mitigate the interference effect when combining cardio and strength training?

To mitigate interference, reduce cardio duration and frequency (e.g., 30 minutes, 3 times/week), choose low-impact modalities like cycling, and separate cardio from lower-body strength training by at least 24 hours. For bodybuilders or powerlifters, focus on caloric expenditure rather than cardio performance goals.

How should runners incorporate resistance training to improve performance?

Runners should lift 2-3 times per week, focusing mostly on lower body exercises that are a mix of explosive and heavier resistance training, with low reps (e.g., 4-6) and not too much volume. Unilateral work (split squats, one-leg RDLS) is important, along with core work. Sessions should be kept relatively short and not performed right before speed work or long runs.

Does rowing have a different interference effect compared to running or cycling?

Rowing is more similar to cycling in terms of lower eccentric damage than running, making it generally less impactful on lower body strength. However, since rowing heavily involves the upper body, programming should place rowing sessions away from upper body strength training days (e.g., rowing on Tuesday/Thursday/Saturday if benching on Monday/Wednesday/Friday).

What is myonuclear domain theory, and is muscle memory solely due to myonuclei?

Myonuclear domain theory suggests muscle hypertrophy adds myonuclei, which are retained during atrophy (myonuclear permanence), allowing faster regrowth. However, current research indicates myonuclei are lost at a slower rate than muscle mass but are not truly permanent. While myonuclei contribute, other mechanisms like epigenetic modifications also play a significant role in muscle memory.

What are common errors in meta-analyses, especially in sports science?

Common errors include 'double counting' multiple outcomes from the same participants, not accounting for time effects in repeated measures, and incorrectly treating standard errors as standard deviations. These can lead to astronomically huge effect sizes and undermine the validity of pooled results.

How should one approach progression frameworks for hypertrophy training?

It's crucial to distinguish between 'volume load' (reps x load) and 'set volume' (number of hard sets). While increased volume load signals progression, plateaus indicate a need for change. True volume increases (adding sets) can stimulate further growth when reps or load can no longer be increased. An auto-regulated double progression model, focusing on RPE and rep targets before increasing load, is a recommended approach.

Key Moments

2020's Most Notable Research (with guests Eric Helms and Mike Zourdos) - Episode 51

Stronger By Science

Education4 min read105 min video

Nov 26, 2020|7,242 views|232|26

Stronger By Science podcast

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Key Moments

TL;DR

Experts discuss 2020's top exercise and nutrition research, covering refeeds, concurrent training, and muscle memory.

Key Insights

Refeed-style dieting may help preserve lean body mass compared to continuous calorie restriction, although more research is needed.

Concurrent training (combining resistance and aerobic exercise) can be managed to minimize interference with strength and hypertrophy gains by optimizing modality, duration, and frequency.

Myonuclei (muscle cell nuclei) are likely retained after short periods of muscle atrophy, contributing to faster retraining, but are not permanent and may not be the sole driver of muscle memory.

Meta-analyses, while high on the evidence hierarchy, can contain methodological errors (e.g., double counting, mishandling time effects) that significantly alter conclusions, necessitating careful scrutiny.

Progression frameworks for hypertrophy should consider both set volume and volume load, using metrics like RPE and reps in reserve for diagnostic clarity and to inform adjustments.

Resistance training can significantly benefit running performance by improving stride length, running economy, and reducing fatigue, when programmed appropriately for runners.

THE MASS RESEARCH REVIEW AND ITS MISSION

The episode features the editorial team of the MASS Research Review, a monthly publication that breaks down and applies the latest strength, physique, and nutrition research. The team, including hosts Greg and Eric, along with guests Dr. Mike Zourdos and Dr. Eric Helms, discuss their favorite studies from 2020. They highlight the practical application of complex research for individuals and clients, emphasizing accessible yet comprehensive insights. The discussion also touches on the MASS annual charity sale benefiting the American Foundation for Suicide Prevention, underscoring the importance of community support and awareness.

REFEEFS AND LEAN MASS PRESERVATION

Dr. Helms discusses a study on bodybuilding-style refeeds, comparing continuous energy restriction to a diet with five days of deficit followed by two days at maintenance. While not finding statistically significant differences in overall fat mass loss, the refeed group lost significantly less dry fat-free mass and showed less reduction in resting metabolic rate. This suggests that refeeds may be beneficial for preserving lean body mass, although limitations like sample size and the measurement of dry fat-free mass require further investigation. The authors and guests agree that refeeds are a justifiable approach, especially considering anecdotal evidence from the bodybuilding community.

NAVIGATING CONCURRENT TRAINING EFFECTIVELY

Dr. Zourdos delves into the interference effect of concurrent training (combining resistance and aerobic exercise). He presents a study on Danish military members showing that even with significant amounts of cardio and endurance training alongside resistance work, participants still experienced strength and hypertrophy gains. While acknowledging that a dedicated strength-only group might see superior results, he emphasizes that interference can be minimized by logical programming. This includes managing the duration and modality of cardio, separating it from lower body resistance training by at least 24 hours, and prioritizing caloric expenditure over pure performance for non-athlete populations.

THE SCIENCE BEHIND MUSCLE MEMORY AND MYONUCLEI

Greg discusses the concept of myonuclei-facilitated muscle memory, where retained myonuclei after muscle atrophy lead to faster retraining. The reviewed article highlights that while myonuclei are likely retained after short detraining periods (months), they are not permanent and can be lost over years or decades. A key study on mice showed that despite muscle size returning to baseline after testosterone withdrawal, myonuclei density remained elevated, leading to faster hypertrophy upon retraining. However, the significant difference in hypertrophy could not be fully explained by the minor difference in myonuclei density alone, suggesting other factors like epigenetic modifications also play a crucial role.

SCRUTINIZING META-ANALYSES IN SPORTS NUTRITION

Dr. Helms critiques several meta-analyses on supplements like carnitine, arginine, and Vitamin D, identifying common methodological flaws. Issues such as double counting data points from the same participants, failing to account for time effects in repeated measures, and confusing standard errors with standard deviations significantly skewed results. After recalculating the data for these meta-analyses, the conclusions often changed from significant to non-significant, challenging the reliability of top-tier evidence. This underscores the need for rigorous quality control and expert review of meta-analyses before accepting their conclusions as definitive.

PROGRESSION FRAMEWORKS FOR HYPERTROPHY

Dr. Helms reviews a concept piece on progression frameworks for hypertrophy, differentiating between volume load and set volume. He emphasizes that while increasing sets is readily scalable, load and reps are limited by physical capacity. The discussion highlights the importance of understanding that volume load increases (through reps or load) indicate progressive overload, but when it plateaus, increasing set volume can be a strategy for further growth. This approach, often incorporating auto-regulated double progression models, allows for more diagnostic clarity in training, enabling individuals to identify what specific changes drive adaptation and progress effectively.

ADAPTING TRAINING FOR CARDIOVASCULAR GOALS

Shifting perspective, the discussion addresses individuals whose primary goal is cardiovascular performance (running, cycling) and who want to incorporate lifting. Dr. Zourdos explains that resistance training can be highly beneficial for runners by improving stride length, running economy, and overall performance. However, it should be specific, focusing on lower body strength with a mix of explosive and heavier movements, avoiding excessive hypertrophy that could be detrimental. Key recommendations include 2-3 sessions per week, moderate volume, unilateral exercises, and smart programming around intense running sessions, prioritizing performance improvement without adding unnecessary bulk.

Mentioned in This Episode

●Supplements

●Software & Apps

●Companies

●Organizations

●Studies Cited

●Concepts

●People Referenced

Optimizing Training for Muscle Growth and Concurrent Development

Practical takeaways from this episode

Do This

Utilize refeeds (2 days at maintenance after 5 days of dieting) to preserve lean body mass during fat loss phases.

When combining cardio and resistance training, space out cardio from lower body strength work (ideally 24 hours apart).

Choose low-impact cardio modalities like cycling or rowing over high-impact running to reduce muscle damage and minimize interference for strength goals.

For runners, incorporate resistance training focusing on low reps (4-6) of explosive and heavy movements, mostly lower body, 2-3 times per week.

Use unilateral exercises like split squats and one-leg RDLS in resistance training for runners.

Employ auto-regulated double progression models by setting an RPE target and increasing load only after consistently hitting rep targets across all sets.

Focus on diagnostic clarity in programming: make one change at a time to effectively assess its impact on progress.

Consider set volume as the primary driver for hypertrophy, and use plateaus in volume load (reps x load) as an indicator to increase set volume.

Avoid This

Don't dismiss refeeds based on small sample sizes or minor statistical non-significance if other indicators lean towards benefit.

Avoid extreme concurrent training protocols (e.g., 6 days of running on top of 5 days of lifting) that are designed to maximize interference effects.

For strength athletes, don't combine heavy lower body lifting and intense cardio on the same day if possible.

For runners, avoid high-volume hypertrophy resistance training if mass gain specifically impedes running performance.

Don't solely rely on High-Intensity Interval Training (HIIT) for cardio if it causes mental fatigue or excessive muscle damage that impairs subsequent resistance training sessions.

Avoid blindly adopting complex training programs with too many simultaneous variable changes; prioritize understanding what actually works for the individual.

Don't treat meta-analyses as infallible 'trump cards' without scrutinizing their methodology and potential errors in sports nutrition and exercise science.

Common Questions

The MASS Research Review stands for Monthly Applications in Strength Sport, publishing 10 pieces of content monthly on strength, physique, and nutrition research. During their annual sale, 100% of the first monthly subscription payment ($21) goes to the American Foundation for Suicide Prevention.

Topics

Resistance Training Nutrition & Diet Human Performance Science & Mathematics Concurrent Training Muscle Memory Refeed Strategies Meta-analysis Methodology Training Programming

Mentioned in this video

personGreg Nuckols

One of the guest co-hosts and authors of the MASS Research Review. He also published a review on myonuclear accretion.

personEric Helms

Guest co-host and author of the MASS Research Review, researcher at Sports Performance Research Institute New Zealand, and co-founder of 3D Muscle Journey. He is a multi-sport strength athlete.

personMike Zourdos

Guest co-host and author of the MASS Research Review, associate professor at Florida Atlantic University, whose research focuses on resistance training for strength and muscle growth.

organizationMASS Research Review

Monthly Applications in Strength Sport, a publication that provides concise and applicable breakdowns of the latest strength, physique, and nutrition research.

softwareStrongerByScience.com

Website where articles about myonuclear accretion and Vitamin D supplementation are freely available.

personBill Campbell

A 'good doctor' whose lab produced the first ecologically valid refeed style research relevant to bodybuilding.

personLayne Norton

A coach mentioned for evolving the concept of 'cheat meals' to 'refeeds' in bodybuilding circles since the early to mid-2000s.

mediaIron Culture

Omar's podcast, mentioned humorously as the likely destination for the current 'episode'.

personMichael Jordan

NBA legend whose trash talk during a playoff game is, anecdotally, said to have psychologically impacted Muggsy Bogues' shooting performance for the rest of his career.

personDaniel Kahneman

Psychologist whose concept 'what you see is all there is' is used to explain why single scientific findings can be given undue weight.

supplementCarnitine

A supplement reviewed in a meta-analysis where recalculations showed different, often non-significant, results from the original publication.

supplementArginine

A supplement reviewed in a meta-analysis where recalculations showed different, often non-significant, results from the original publication.

supplementVitamin D

A supplement whose meta-analysis was re-evaluated, showing a dramatically different pooled effect size and conclusion when methodological errors were corrected.

personMike Israetel

A co-author of recent SCJ articles on hypertrophy, part of a broad discussion on progression frameworks.

personJared Feather

A co-author of recent SCJ articles on hypertrophy, part of a broad discussion on progression frameworks.

organizationIPF

International Powerlifting Federation, whose high-level lifters work with Mike Tuchscherer.

toolWilks score

A formula that evaluates the strength of a powerlifter against other powerlifters across different body weights, used as a metric for powerlifting achievement.