What is Fat-Free Mass Index (FFMI) and what are typical ranges?

Fat-Free Mass Index (FFMI) is a measure of lean mass relative to height, often used to assess muscularity. Recent studies in college-aged female athletes showed median FFMI values around 17-18, with some individuals reaching 20-22 and one over 25. For male college athletes, substantial numbers were above 25, with some nearing 31, challenging the old '25 as natural limit' rumor.

Is dietary nitrate effective for strength athletes, and are supplements reliable?

Dietary nitrate shows promise for strength athletes due to potential direct effects on muscle contractile function, moving beyond traditional aerobic endurance benefits. However, supplement reliability is poor; a study found up to a 50-fold range in nitrate content, with only 5 out of 24 products consistently providing a minimum effective dose. Getting nitrate from diverse food sources is currently a more reliable strategy.

How do genetics influence caffeine's effect on blood pressure?

A study found a gene-diet interaction where individuals genetically predisposed to high blood pressure showed a negative relationship with high caffeine intake from coffee. While research on caffeine genetics is mixed, it tentatively suggests being a fast metabolizer is preferable, but a clear consensus is still emerging.

What's the issue with 'non-responders' in exercise science research?

The term 'non-responder' originated from early studies but is often criticized for its application, especially when based on arbitrary statistical cutoffs rather than clear biological criteria. Misclassifying individuals can lead to misleading conclusions about supplement effectiveness, such as claiming a supplement works well only for 'responders' who are simply the top half of a normal distribution.

How can one identify statistically fragile research findings?

The 'fragility index' reveals how many subject outcome changes would reverse a study's significant finding. In clinical nutrition trials, 75% of studies had a fragility index of two or less, meaning just one or two subjects changing status would flip the conclusion. This highlights that p-values close to 0.05 often indicate highly fragile and less reliable findings, emphasizing the need for replication and looking at effect sizes.

Can weekend recovery sleep fully offset sleep debt from a work week?

No, two nights of recovery sleep cannot fully restore all functions lost during a week of poor sleep. A study found that while free fatty acid kinetics returned to baseline, insulin sensitivity remained significantly impaired after five nights of sleep restriction, even with two recovery nights. Consistent good sleep is necessary for optimal health benefits.

Do artificial sweeteners increase stroke risk?

A study linking high diet soda intake to increased stroke risk was scrutinized, revealing that diet soda drinkers typically have numerous other confounding health and lifestyle factors (e.g., higher smoking rates, obesity, diabetes, lower activity). Even with statistical controls, the absolute incidence rates for stroke showed no difference between high and low diet soda consumers, suggesting a weak or non-existent direct link.

How do processed foods affect calorie intake and satiety?

Kevin Hall's study showed that people consuming ultra-processed foods ate about 500 more calories per day than those on an unprocessed diet, without experiencing differences in perceived pleasantness, fullness, or satisfaction. This suggests processed foods may override biological mechanisms that regulate food intake, potentially contributing significantly to overconsumption and obesity.

What is a body fat set point, and can it be reset?

A body fat set point is a theoretical homeostatic level that biological mechanisms try to defend against changes in body fat. While these mechanisms exist, they can be overpowered by chronic overconsumption, leading to obesity. It's unclear if a set point can be 'reset' after significant weight gain and loss, as sustained changes in leptin signaling, insulin sensitivity, and behavioral components make long-term weight maintenance difficult for those who have been obese.

How should people think about metabolism and metabolic adaptation?

Instead of viewing metabolism as a static 'good' or 'bad' state, it's more helpful to think of it as an 'always shifting landscape' that constantly adapts to what you're doing. This perspective emphasizes that the body is a living, breathing organism constantly responding to its environment, promoting a more fluid understanding of metabolic changes rather than fixed dichotomies.

Key Moments

Coaching Cues, Fat-Free Mass Index, Non-Responders, and Dr. Brad Dieter (Podcast Episode 10)

Stronger By Science

Education5 min read146 min video

Jul 25, 2019|5,807 views|161|18

Stronger By Science Podcast

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Key Moments

TL;DR

Coaching cues, fat-free mass index, nitrate, caffeine, sleep, stats, processed foods, and body fat set points discussed.

Key Insights

Exaggerated coaching cues can be effective for improving lifting technique by helping athletes feel the consequences of suboptimal form.

Fat-free mass index (FFMI) research in females is growing, and values above 25 in males are not uncommon in trained athletes, challenging previous assumptions.

Dietary nitrate's performance benefits might extend beyond endurance to power and strength, but product standardization and food variability make consistent dosing challenging.

Caffeine's ergogenic effects on performance appear consistent across different genetic metabolizers and habituation levels, though its impact on blood pressure in predisposed individuals is noted.

Statistical methods in research, particularly regarding 'responders' and 'non-responders' and the fragility of statistically significant results, require careful scrutiny.

Two nights of recovery sleep may not fully restore insulin sensitivity after sleep deprivation, highlighting the importance of consistent sleep.

Ultra-processed foods lead to higher calorie intake without affecting feelings of fullness, contributing to overconsumption and potential weight gain.

Body fat regulation involves mechanisms that defend against changes, but these can be overpowered by consistent environmental stimuli, and resetting the 'set point' after significant weight gain is complex.

COACHING CUES AND TECHNIQUE ADJUSTMENTS

The podcast begins with a practical coaching tip on using exaggerated cues in lifting. Instead of simply guiding athletes toward correct form, coaches can be more effective by cueing them to overemphasize their existing mistakes or to overcorrect the desired movement. This allows athletes to physically feel the negative consequences of poor technique or the extreme of the correct technique, enabling their nervous system to find the optimal balance more efficiently. This approach is particularly useful for experienced lifters with ingrained habits, contrasting with basic position cueing for beginners.

FAT-FREE MASS INDEX BENCHMARKS

Recent research is providing more insights into fat-free mass index (FFMI) in both male and female athletes. Studies on college-aged females are establishing reference ranges, noting that while many athletes fall within typical ranges, some exceptional individuals exhibit higher FFMI values. For males, research on diverse athletic populations continues to show FFMI values well above 25, challenging the notion that this is a strict upper limit for drug-free athletes. Factors like genetics, intensive training, and support services contribute to these higher observed values.

DIETARY NITRATE AND PERFORMANCE

The potential performance benefits of dietary nitrate are expanding beyond endurance to power and strength. However, achieving a consistent and effective dose is challenging due to high variability in nitrate content among beetroot juice products and even within the same product. While food sources can provide nitrate, their content is also unpredictable. This inconsistency makes it difficult for athletes to reliably use nitrate supplementation for ergogenic effects, suggesting a need for better product standardization or a focus on consuming a variety of high-nitrate foods.

CAFFEINE RESPONSE AND GENETICS

Research on caffeine continues to explore genetic influences on individual responses. While there's variability in how people metabolize caffeine and how it affects physiological markers, studies suggest that caffeine's ergogenic benefits for aerobic and neuromuscular performance are largely consistent, regardless of genetic profile or habituation level. Nevertheless, high caffeine intake may negatively affect blood pressure in individuals genetically predisposed to hypertension. The consensus is that caffeine generally enhances performance, and the debate continues regarding whether it merely restores baseline or provides an actual boost.

STATISTICAL METHODOLOGY IN RESEARCH

The discussion highlights critical issues in research methodology, particularly the determination of 'responders' and 'non-responders' and the fragility of statistically significant results. The term 'non-responder' is often criticized for its arbitrary application. Furthermore, many studies, especially in nutrition, have results that could be reversed by changing just one or two participants' data points. The accuracy and interpretation of effect sizes are also frequently problematic, with calculations that inflate the perceived impact of interventions. This underscores the importance of critically evaluating research findings, not just citing single studies.

SLEEP DEBT AND RECOVERY

A study examining recovery from sleep restriction found that while two nights of extra sleep could restore certain physiological markers like free fatty acid kinetics, it did not fully improve insulin sensitivity. This suggests that cumulative sleep debt can have persistent effects, particularly on metabolic health, and cannot be entirely compensated for by short periods of extended sleep. The findings emphasize the need for consistent, adequate sleep rather than relying on weekend catch-ups to maintain optimal health and performance.

PROCESSED FOODS AND CALORIE INTAKE

A controlled study comparing ultra-processed foods to unprocessed foods revealed that participants consumed approximately 500 more calories per day on the processed diet. Notably, this increased intake did not correlate with greater feelings of fullness or palatability satisfaction, suggesting that processed foods may override natural appetite regulation mechanisms. This finding suggests that the hyper-palatable and easily consumed nature of processed foods contributes significantly to overconsumption and, consequently, to the rising rates of obesity.

BODY FAT SET POINTS AND WEIGHT REGULATION

The concept of body fat 'set points' or 'settling points' suggests that the body actively defends certain levels of fat mass through various homeostatic mechanisms. While these defense mechanisms exist, they can be overwhelmed by consistent environmental stimuli, such as overeating and reduced physical activity over extended periods. This overpowering of natural regulation is believed to contribute to the obesity epidemic. Furthermore, substantial weight loss may not always lead to a complete reset of this 'set point,' as biological and behavioral changes associated with previous obesity can make long-term weight maintenance challenging.

ARTIFICIAL SWEETENERS AND HEALTH RISKS

Large epidemiological studies linking artificially sweetened beverages to negative health outcomes, like increased stroke risk, often suffer from confounding factors. Participants who consume diet sodas frequently also tend to exhibit other risk behaviors such as smoking, obesity, and a poorer overall diet. While statistical adjustments are made, they may not fully account for these combined effects. The actual incidence rates of outcomes like stroke often show minimal difference between high and low consumers once these factors are considered, questioning the strong claims made in many media reports about the dangers of artificial sweeteners themselves.

THE CAPSAICIN AND BEVERAGE STUDY

A light-hearted study investigated the efficacy of common beverages in reducing the oral burn from capsaicin (the compound in spicy foods). The results showed that while water and seltzer provided some relief, beverages like whole milk, skim milk, beer, cola, and notably, Kool-Aid, were more effective. The study's categorization of Kool-Aid as 'fruit punch' was highlighted as a humorous point. This research offers practical insights for those seeking relief from spicy food discomfort.

Mentioned in This Episode

●Supplements

●Products

●Software & Apps

●Companies

●Organizations

●Books

●Studies Cited

●Concepts

●People Referenced

Common Questions

Exaggerated cues work in two ways: by 'amplification of error' to make lifters feel the consequences of mistakes, enabling their nervous system to self-correct; and by over-correcting in the desired direction, allowing lifters to find their optimal neutral position as they naturally drift back. This is especially effective for lifters with established habits.

Topics

Nutrition & Diet Mental Health & Psychology Strength Training Caffeine Metabolism Statistical Methodology Processed Foods Metabolic Adaptation Human Performance Sleep Deprivation Body Fat Set Point Lifting Technique Fat-free Mass Index Dietary Nitrates Artificial Sweeteners

Mentioned in this video

Studies & Research

De Gonzales et al. 2015

Study that measured nitrate content in conventional produce from grocery stores in different US cities, revealing high variability (e.g., spinach nitrate from 65 to 8,000 ppm).

Melanie's et al. study

A study reviewed in Mass (Volume 1, Issue 1) that examined the effect of two different correction strategies on snatch technique in weightlifting, specifically the 'amplification of error' method.

Porcelli et al. 2016

Study showing that food sources of nitrate (fruits and vegetables) can provide an effective dose of 8.2 millimoles (500mg) for performance benefits.

Products

Beet It Sport

A beet juice product that performed well in testing for consistent nitrate content, but is noted for being quite pricey.

Kool-Aid

Grape-flavored drink, controversially categorized as fruit punch in a study on reducing capsaicin burn, shown to be effective.

People

Matthew Walker

A well-known sleep researcher and popularizer of sleep research who wrote the book 'Why We Sleep', increasing public awareness of sleep debt.

Julius Maddox

Powerlifter known for bench press, recently posted 610 lbs for 8 reps, showcasing his impressive strength and continued improvement in the sport.

Kirill Sarychev

Known powerlifter, mentioned for doing 600 lbs for 5 reps and his past world record in bench press.

Jesse Norris

Powerlifter who previously totaled 2015 lbs at 198 lbs, currently the only tested lifter to exceed 2000 lbs at that bodyweight.

Eric Spoto

Previous bench press record holder, mentioned in comparison to Julius Maddox's performance.

Ashton Rouska

Powerlifter who unofficially broke an IPF world record at 105 kg, weighing in just over his usual 93 kg class.

Tian Tao

Weightlifter who clean and jerked 231 kg at 96 kg, close to the old world record, in a tune-up meet for the Olympics.

Gary Taubes

Journalist and storyteller who debated Stephan Guyenet on the Joe Rogan podcast about obesity, carbohydrates, and insulin's role, viewed as having a 'scientism perspective'.

Brad Dieter

Guest and expert on the podcast, with a background in biomechanics, exercise physiology, molecular biology, nephrology, and data science. He is involved in industry, entrepreneurship, and scientific advisory boards.

Kevan Hall

Lead researcher at the NIH for dietary and nutrition interventions, who conducted a highly controlled study on processed food intake.

Stephan Guyenet

Neurobiologist and expert on obesity, who debated Gary Taubes on the Joe Rogan podcast, known for his data-driven approach to understanding obesity causes.

Organizations

CNN

Cable news network, mentioned as an example of media outlets that often publish 'clickbait' health-related articles.

ScienceAlert

Science news website, mentioned as an example of media outlets that often publish 'clickbait' health-related articles.

IPF

Governing body for powerlifting, mentioned for rules regarding world record setting at meets and recent changes to weight classes.

NIH

Research institution where Kevan Hall is a lead researcher, indicating the source of highly controlled dietary intervention studies.

Companies

ESPN

Sports network, mentioned as an example of media outlets that often publish 'clickbait' health-related articles.

Macros Inc

A company mentioned in the introduction as one of Brad Dieter's affiliations.

Eat To Perform

A company co-run by Dr. Brad Dieter, which evolved from an information product business to a coaching and software technology business.

Coca-Cola

A beverage company, with its product mentioned as a source of 1000 calories/day for some individuals, highlighting the potential benefit of switching to diet sodas for health.

Software & Apps

Joe Rogan Podcast

Podcast where a debate on obesity causes and the role of carbohydrates/insulin took place between Gary Taubes and Stephan Guyenet.

Science Driven Nutrition

Dr. Brad Dieter's personal blog where he shares articles, with a new one expected after the Inland Empire Fitness Conference.

Concepts

CYP1A2 enzyme

The enzyme largely responsible for caffeine metabolism, with genetic variations influencing how individuals respond to caffeine.

Leptin

Hormone involved in body fat regulation; people who gain and lose a lot of weight may show sustained leptin resistance.

DEXA

Measurement technique used for body composition analysis in studies, particularly for fat-free mass index calculation.

insulin resistance

Physiological state impacting overall metabolism, noted as being different in people who were obese and then became lean compared to those always lean.

Media

Office Space

A movie referenced humorously to introduce Dr. Brad Dieter's diverse professional roles, asking 'what exactly is it that you do around here?'.

Supplements

Creatine

A supplement often studied for increasing reps to fatigue; its 'non-responder' status is more identifiable through tissue samples than exercise responses.

Books

Why We Sleep

A book authored by Matthew Walker, which has increased public awareness about the importance of consistent good sleep and the limitations of recovering from sleep debt.

Cochrane Review

Example of a rigorous systematic review that includes detailed inclusion/exclusion criteria, quality ratings, and bias assessment, used to counter criticisms of meta-analyses.

Drugs & Medications

Metformin

Medication used for blood sugar control, mentioned in the context of standard care for diabetes, affecting the perceived benefit of new dietary interventions.

Statins

Medication used for elevated cholesterol, mentioned in the context of standard care for cardiovascular disease, affecting the perceived benefit of new dietary interventions.

Fibrate

Medication (specifically 'fenofibrate' inferred from context) used for elevated triglycerides, mentioned in the context of standard care for cardiovascular disease.