What is the key takeaway from the meta-analysis on building muscle in a caloric deficit?

The meta-analysis indicates that while an energy deficit impairs lean mass gains, it doesn't significantly impact strength gains. A deficit of around 500 calories per day was predicted to fully blunt lean mass gains in the study's model, but recomposition remains feasible for many, especially those with more body fat to lose or less training experience.

How much energy do people typically burn during a resistance training session?

According to a study discussed, people in the gym are likely burning about 6 kilocalories per minute during a typical resistance training session, with a range of 4 to 8 kilocalories per minute. This equates roughly to the energy expenditure of a brisk walk.

Are there sex differences in muscle activation during the bench press?

A study suggests that female benchers, on average, tend to rely more on their triceps, while male benchers rely more on their pecs. This was observed in both EMG data and joint moment data, even with standardized grip width.

Does attentional focus impact strength development?

A meta-analysis found that an external attentional focus (focusing on the outcome of the movement) acutely improves strength performance compared to an internal focus. There is weak to moderate evidence suggesting it also leads to greater long-term strength gains, particularly in lower body movements.

What is sarcoplasmic hypertrophy, and how does it relate to muscle growth?

Sarcoplasmic hypertrophy refers to a disproportionate increase in the sarcoplasm (non-contractile elements) portion of a muscle fiber relative to its contractile proteins (myofibrils). A study showed a wide individual variation in myofibrillar density changes during resistance training, indicating that sarcoplasmic hypertrophy or myofibrillar packing can both occur, and neither was predictive of total hypertrophy.

What are the common shortcomings of deeply plant-based protein consumption?

When replacing animal proteins with plant proteins, there can be potential micronutrient shortcomings. Eric encourages regular health check-ups and testing for vitamin and mineral levels to manage this, noting that many health plans cover annual general health visits.

How do energy compensation models affect our understanding of exercise calories?

The additive model, which assumes all calories burned during cardio are added to daily energy expenditure, works best in neutral or positive energy balance. However, in negative energy balance (dieting), an alternative model incorporating compensation (where the body reduces other energy expenditures) fits the data better, meaning you might not burn as many 'net' calories as expected from exercise.

How effective is cold exposure for fat loss?

While physiologically interesting, cold exposure is deemed impractical for clinically relevant or practically significant fat loss. The increase in energy expenditure from acute cold exposure is too small in magnitude and too short-lived, while the intervention itself is uncomfortably harsh.

What are some examples of nutrition advice that has been debunked?

The podcast highlights authors like Gary Taubes (carbohydrate-insulin model), Brian Wansink (unreliable research leading to retractions), and David Avocado Wolf (fringe nutrition conspiracy theories and New Age spirituality) as examples of figures whose information has been debunked or is not scientifically sound.

Key Moments

Body Recomposition, Estimating Energy Expenditure, and Sex Differences in the Bench Press (Ep 84)

Stronger By Science

Sports5 min read122 min video

Apr 28, 2022|9,224 views|273|32

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Key Moments

TL;DR

Podcast covers recomposition, energy expenditure, sex differences in bench press, and training around injuries, featuring "Best of MASS" research.

Key Insights

Body recomposition (building muscle and losing fat simultaneously) is feasible for many individuals, especially the untrained or those with significant body fat.

Energy deficits impair lean mass gains more than strength gains; the larger the deficit, the more challenging it is to build muscle.

Resistance training burns approximately 6 kcal per minute, a heuristic that holds true for most standard workouts but may vary.

Sex differences in the bench press may exist, with females potentially relying more on triceps and males on pecs at sub-maximal loads.

External attentional focus appears to enhance acute strength performance and may lead to greater strength gains over time compared to internal focus.

While sarcoplasmic hypertrophy is possible, individual responses to training vary widely, and its predictive factors are still being researched.

INTRODUCTION AND PODCAST OVERVIEW

The Stronger By Science podcast episode, hosted by Eric Trexler and Greg, discusses various fitness and research topics. The conversation highlights how listeners can support the podcast through subscriptions, newsletters, and app usage. A significant portion of the episode is dedicated to reviewing articles from the 'Best of MASS' issue, a collection of their favorite research from the past year, available for free download.

FEATS OF STRENGTH AND TRAINING MODIFICATIONS

The episode begins by acknowledging Christopher Burr-Bicky's impressive deadlift, ranking among the all-time heaviest. A discussion follows on the controversial topic of allowing straps in powerlifting, with the argument that it could increase accessibility. Eric shares a personal breakthrough in managing chronic hip and pelvic pain, diagnosing it as a nerve entrapment issue after years of seeking help. He details his current approach to training around this injury, focusing on specific movements and avoiding those that exacerbate pain.

NAVIGATING HIP PAIN AND ADAPTING TRAINING

Eric elaborates on his strategy for training with hip pain, emphasizing that this is not medical advice but his personal approach. He has been focusing on hip flexion and adduction, avoiding deep hip flexion, and utilizing free weights and cables. Upper body training also involves modifications to prevent excessive lumbar flexion. For cardio, he has found success with basketball, rope climbers, and swimming, as these activities allow for controlled hip movement and hip flexor strengthening without aggravating his condition.

BODY RECOMPOSITION: FEASIBILITY AND EVIDENCE

The podcast delves into the concept of body recomposition, the simultaneous pursuit of fat loss and muscle gain. Eric discusses his article on this topic, which reviews a meta-analysis by Murphy et al. (2021) on energy deficiency's impact on resistance training. The findings suggest that while energy deficits significantly impair lean mass gains, they have a less pronounced effect on strength gains. The study indicated that a deficit of around 500 calories per day might blunt lean mass gains, but this is a model-based prediction, not a strict law.

ENERGY EXPENDITURE AND RESISTANCE TRAINING METRICS

Greg reviews a study by Zhao et al. that aimed to create a heuristic for estimating energy expenditure during resistance training. The research found that various resistance training protocols (different sets, reps, and intensities) resulted in approximately 6 kilocalories burned per minute, with a range of 4 to 8 kcal. This estimate is comparable to a brisk walking pace and is considered a reasonable ballpark figure for general resistance training sessions, though it may not apply to extremely high-volume or specialized protocols.

SEX DIFFERENCES IN BENCH PRESS BIOMECHANICS

Another article discussed examines sex differences in bench press technique and muscle activation by Mouser, Hunt, and Crossog. The study found that, on average, female benchers exhibited more triceps dominance, while male benchers showed more pec dominance, supported by EMG and joint moment data. This contrasts with findings at maximal loads, suggesting potential sex-based differences in how the nervous system recruits muscles during the bench press, with females potentially leaning more on triceps at sub-maximal loads and males more on pecs.

ATTENTIONAL FOCUS AND STRENGTH DEVELOPMENT

The meta-analysis by Gurgic et al. on attentional focus strategies is reviewed, exploring the impact of internal (focusing on body sensations) versus external (focusing on the outcome) cues on strength. Acutely, an external focus was found to enhance strength performance. While longitudinal data is limited, the evidence suggests that an external focus may also lead to greater strength gains over time, though this is more pronounced for lower body measures and appears to be heavily influenced by study design, particularly the inclusion of specific muscle groups like the biceps.

SARCOPLASMIC HYPERTRO জৈ

Greg discusses a study by Rupa et al. on sarcoplasmic hypertrophy, defining it as a disproportionate increase in the non-contractile portion of muscle fibers. The research on untrained men after 10 weeks of resistance training showed no significant average change in myofibrillar density, indicating balanced growth. However, individual responses varied widely, with some experiencing considerable myofibrillar packing and others significant sarcoplasmic hypertrophy. This suggests that while the average response is balanced, personal variation is substantial, and the concept of 'bro science' dismissal of sarcoplasmic hypertrophy may be unfounded.

ADDITIONAL RESEARCH ARTICLES AND MEDIA RECOMMENDATIONS

The episode highlights other articles in the 'Best of MASS' issue, including those on plant-based proteins, collagen supplementation, energy compensation during dieting, the utility of wearable technologies, and the effectiveness of cold exposure for fat loss. Media recommendations for 'Severance' and 'Slow Horses' are given, while 'Is It Cake?' is strongly advised against, with the hosts humorously reflecting on outdated nutrition theories and problematic researchers like Gary Taubes, Brian Wansink, and David Avocado Wolfe.

Mentioned in This Episode

●Software & Apps

●Companies

●Books

●Studies Cited

●People Referenced

Common Questions

You can download the 'Best of MASS' issue for free at strongerbyscience.com/mass-best-of. It compiles favorite articles from the past year.

Topics

Sex Differences In Training Attentional Focus

Mentioned in this video

People

Kristof Weirbicky

A powerlifter who recently pulled the third heaviest deadlift of all time (490 kg or 1080 lbs) in the gym, weighing 104 kg (230 lbs).

Hafthor Bjornsson

Holds the record for the heaviest deadlift (501 kg).

Jason Yore

A physical therapist on the Stronger By Science coaching team who diagnosed Eric's hip pain as a nerve entrapment issue after five years of searching for a diagnosis.

Dan Feldman

Powerlifter and dietitian who informed Eric about health insurance coverage for annual general health visits, specifically vitamin testing.

Lawrence Judd

Co-authored an article with Eric Helms on the feasibility of recomposition.

Brian Wansink

Former professor whose research on nutrition and eating behavior was found to be unreliable, leading to retractions and loss of employment.

Media

Iron Culture Podcast

A podcast expected to discuss the other half of the 'Best of MASS' issue.

Is It Cake?

A Netflix show where bakers create realistic cakes that look like other objects, described as "painful" and "trash content" by the speaker.

I Can See Your Voice

Another Netflix show briefly mentioned as being even worse than "Is It Cake?".

Studies & Research

Mauser, Hunt, and Crosshog

Researchers of a study on bench press biomechanics, exploring how sex and training experience affect joint moments and muscle activation.

Murphy et al. 2021

Meta-analysis titled 'Energy deficiency impairs resistance training gains in lean mass but not strength' which found energy deficits impaired lean mass gains but not strength gains, with a predicted threshold of 500 calories/day for blunting lean mass gains.

Krol and Golus

Prior study on EMG in bench press with increasing loads, found sex-based differences in pec and triceps EMG increases towards maximal loads.