Does type 2 diabetes prevent muscle growth?

No, type 2 diabetes does not make muscle growth impossible. Research suggests that it might reduce the rate of muscle growth by about 50% compared to non-diabetics, but this figure might be an overestimation due to differences in study populations and training interventions. Muscle growth is still achievable for individuals with type 2 diabetes.

Does Metformin inhibit muscle hypertrophy?

Current research, particularly the MASTERS trial, suggests Metformin may have a small negative impact on muscle growth. This is possibly due to its effects on AMPK signaling, which can antagonize the mTOR pathway involved in hypertrophy. However, Metformin is still beneficial for improving insulin sensitivity and potentially preserving muscle function in older, insulin-resistant individuals.

Can a muscle 'pump' temporarily increase strength due to improved leverage?

Theoretically, yes. A muscle pump increases muscle volume, which could lengthen the internal moment arm and provide more advantageous leverage. However, in a practical training scenario, the fatigue incurred to achieve the pump would likely offset any temporary strength gains from improved leverage, making overall performance lower than if the muscle were fresh.

Do caffeine and nicotine affect each other's metabolism or half-life?

Caffeine and nicotine are primarily metabolized by different enzymes, so they generally don't interfere with each other's clearance rates. Nicotine might, in fact, slightly speed up caffeine metabolism by inducing the cyp1 A2 enzyme, though this is debated.

Can grapefruit juice extend the effects of caffeine?

Yes, grapefruit juice can extend the effects of caffeine. It contains the flavone Naringenin, which inhibits the cyp1 A2 enzyme responsible for caffeine metabolism. By inhibiting this enzyme, grapefruit juice slows down how quickly caffeine is broken down, causing it to stay in your system longer.

Is it true that some people have a naturally 'fast' or 'slow' metabolism?

Yes, BMR can vary significantly between individuals of the same size, age, sex, and activity level, sometimes by as much as 800 calories per day. This variability is primarily attributed to differences in relative organ sizes, as internal organs are highly metabolically active.

Can I reduce my daily steps from 25,000 without gaining weight if I keep my calorie intake the same?

Possibly, to some degree. Due to the constrained energy expenditure model, reducing activity when already very active (e.g., from 25k to 20k steps) results in a disproportionately smaller decrease in total daily energy expenditure. While some caloric reduction will likely be needed to maintain weight, it will be less than the calories directly 'saved' from fewer steps, and hunger perceptions should adjust naturally.

How should plyometrics be incorporated into a basketball athlete's offseason training?

Plyometrics should generally be performed at the start of a training session when the athlete is fresh and can give maximum effort. The type, amount, and intensity depend on their current sports-specific activity and other training goals. Avoid placing hard plyo workouts on rest days, as this can impede recovery and place excessive stress on tendons and joints.

Does the Valsalva maneuver (bracing) during heavy lifting cause long-term damage to blood vessels?

There is no direct research demonstrating long-term vascular damage from the Valsalva maneuver in healthy individuals. While it does spike blood pressure and can be dangerous for those with pre-existing vascular conditions, this doesn't mean it causes those conditions. Indirect epidemiological research on chronic occupational heavy lifting exists, but its relevance to controlled, heavy resistance training is unclear.

How much isolation exercise is optimal for muscle growth without overtraining?

There's no single answer, as it depends on individual goals, recovery capacity, and time constraints. For muscles not heavily targeted by main compound lifts (e.g., forearms, calves, rear delts, side delts, biceps, core), 2-4 challenging sets once or twice a week is a general recommendation to cover most bases and achieve significant gains without overdoing it. Listen to your body's recovery cues.

Key Moments

Q&A: Insulin resistance and hypertrophy, stimulant metabolism, and BMR variability (Ep 126)

Stronger By Science

Sports6 min read142 min video

Feb 7, 2024|2,999 views|115|23

Save to Pod

Key Moments

TL;DR

Stronger By Science podcast announces team changes, welcomes new co-hosts, and outlines future content plans.

Key Insights

Stronger By Science is undergoing significant changes to improve content quality and manage workload, including hiring new team members.

Greg will be joined by new co-hosts Milo and Pak for the podcast, with Lindsay stepping back into behind-the-scenes roles.

The podcast will continue its Q&A format, with effective strategies for researching new topics, including using textbooks and scientific reviews.

Insulin resistance and diabetes may slow hypertrophy but do not make it impossible, with Metformin potentially having a small negative impact on muscle growth.

A muscle pump can theoretically enhance short-term strength gains by increasing the moment arm, but this effect may be masked by fatigue.

Stimulant metabolism rates vary, with caffeine and nicotine generally metabolized by different enzymes, thus not significantly interfering with each other.

Basal Metabolic Rate (BMR) shows significant individual variability primarily due to relative organ size, not just overall body size or activity level.

Tapering activity levels requires a proportionate reduction in calorie intake, but appetite regulation typically adjusts well if activity remains moderate.

Plyometric and explosive training should be incorporated at the beginning of a workout when athletes are fresh, not on off days.

While direct research on the long-term vascular effects of heavy bracing is limited, it can exacerbate existing conditions.

The optimal amount of isolation work depends on individual goals, recovery capacity, and the effectiveness of the training.

The 'Art and Science of Lifting' book offers a deep dive into training principles.

PODCAST UPDATES AND FUTURE DIRECTION

The Stronger By Science podcast is undergoing significant changes to address workload and improve content quality. Greg Nuckols, the primary content creator, has been stretched too thin, leading to a decline in the quality of his work. To rectify this, they've hired a podcast editor and a full-time content person for Macro Factor. Most notably, Milo Wolf and Dr. Pak are joining the team full-time, becoming co-hosts for the podcast alongside Greg. Lindsay, who has been co-hosting, will transition back to her behind-the-scenes role managing operations, marketing, and design.

RESEARCH FRAMEWORK FOR NEW TOPICS

Greg outlines a multi-step process for researching unfamiliar topics. The first step involves assessing the depth of knowledge required and the time available, prioritizing topics more relevant to existing expertise. If deep understanding is needed, he suggests starting with textbooks (undergraduate and graduate level) to build a foundational knowledge base. This is followed by reviewing scientific literature, specifically outcome-based systematic reviews and meta-analyses, before delving into mechanistic reviews. Basic physiology and individual studies are consulted as needed, and if further clarification is required, experts in the field are contacted.

INSULIN RESISTANCE, DIABETES, AND HYPERTROPHY

The Q&A addresses the impact of insulin resistance and diabetes on hypertrophy. Research suggests that while type 2 diabetes might slow muscle growth rates by up to 50% compared to healthy individuals, it does not make hypertrophy impossible. Studies show modest lean body mass gains in diabetic populations undergoing resistance training. The effect of Metformin, a common diabetes medication, on hypertrophy is also discussed. While initially hoped to aid muscle growth, a study indicated it may have a small negative impact by interfering with the mTOR pathway, though its benefits for insulin sensitivity and long-term muscle health are acknowledged.

MUSCLE PUMPS AND STRENGTH GAINS

The discussion explores the link between a 'pump' (acute muscle swelling) and short-term strength gains. Theoretically, increased muscle volume could lengthen the internal moment arm of a muscle, providing a mechanical advantage for force production. However, this effect might be offset by the fatigue associated with achieving a pump and may not apply uniformly to all muscles or joint angles. While a pump might offer a slight, temporary strength boost, the practical benefits could be masked by fatigue, making it difficult to measure a significant performance increase.

STIMULANT METABOLISM AND BMR VARIABILITY

The metabolism of common stimulants like caffeine and nicotine is addressed, with the panelists explaining they are generally metabolized by different enzymes and thus don't significantly interfere with each other. Nicotine might even increase caffeine clearance. The concept of 'fast' or 'slow' metabolisms is validated, as Basal Metabolic Rate (BMR) can vary considerably between individuals of similar size and activity levels. This variability is primarily attributed to differences in relative organ size, which contribute significantly to resting metabolic rate.

ACTIVITY LEVELS, ENERGY EXPENDITURE, AND RECOVERY

The effect of reducing activity levels on calorie needs is examined. While a decrease in physical activity necessitates a calorie reduction to maintain energy balance, the required decrease is disproportionately smaller for highly active individuals due to the constrained energy expenditure model. Appetite regulation generally stays coupled with energy expenditure as long as activity levels remain moderate. Furthermore, the integration of plyometrics and explosive training is discussed, emphasizing their placement at the start of workouts when athletes are fresh, and cautioning against performing them on off days. The optimal amount of isolation work is deemed highly individual, dependent on goals, recovery, and desired outcomes.

THE ROLE OF BRACING AND LONG-TERM VASCULAR HEALTH

Direct research on the long-term vascular damage caused by heavy bracing and the Valsalva maneuver is limited. While these techniques significantly increase blood pressure, they are not inherently detrimental to vascular health in otherwise healthy individuals. However, for those with pre-existing conditions exacerbated by blood pressure spikes, avoiding these maneuvers is crucial. Epidemiological studies on occupational heavy lifting suggest potential links to cardiovascular issues, but confounding factors make it difficult to draw definitive conclusions relevant to controlled resistance training practices.

ISOLATION WORK AND INDIVIDUALIZATION

Determining 'too much' isolation work is highly individualized, depending on goals, time commitment, and recovery capacity. Muscles not heavily stimulated by compound lifts (e.g., forearms, calves, rear delts, biceps, core) generally benefit from targeted isolation exercises. The key is to balance training volume with the body's ability to recover and adapt. A general recommendation is 2-3 challenging sets for these neglected muscles, once or twice a week, which is unlikely to lead to overtraining while still providing a stimulus for growth.

PROGRAMMING PLYOMETRICS AND EXPLOSIVE TRAINING

For athletes, particularly in sports like basketball, plyometrics and explosive training are crucial but require careful programming. These should typically be performed at the beginning of a training session when the athlete is fresh to maximize power output and minimize the risk of injury due to fatigue. The intensity and volume of plyometrics should be adjusted based on the athlete's overall training load, sport-specific demands, and recovery status. Performing plyometrics on rest days is generally ill-advised due to the high joint and tendon loading, and low-intensity jumping exercises are considered cardio, not plyometrics.

COOKING AND PERSONAL REFLECTIONS

The Q&A concludes with a lighthearted segment on cooking preferences. Lindsay enjoys Greg's simple yet perfectly executed dishes like pepperoni pizza, chicken biryani, and cookies and cream ice cream, with steak and pesto pasta being a birthday tradition. Greg appreciates Lindsay's well-executed chicken shawarma but notes a tendency for her to underbake certain items or create 'brown mush' when cooking for herself, prioritizing flavor and convenience over aesthetics. Both acknowledge each other's cooking skills and the personal connection to food preparation.

Mentioned in This Episode

●Supplements

●Products

●Tools

●Organizations

●Books

●Studies Cited

●People Referenced

Common Questions

To research unfamiliar topics, start by assessing the required depth of understanding and available time. Prioritize topics closer to your existing knowledge base. Then, consult textbooks for foundational knowledge, followed by systematic reviews and meta-analyses, focusing on outcomes before mechanisms. Finally, address any remaining physiological gaps and, if necessary, consult experts in the field.

Topics

Podcast Management Staffing Changes Research Methods Stimulant Metabolism Caffeine Half-life Nicotine BMR Variability Organ Size Metabolism Basketball Training Valsalva Maneuver Isolation Exercises

Mentioned in this video

Products

Licorice

Described as a 'crazy strong' cyp1 A2 inhibitor, which could significantly extend the effects of caffeine.

Grapefruit juice

Contains Naringenin, a flavone that inhibits the cyp1 A2 enzyme, thereby extending the half-life of caffeine in the body.

Books

Art and Science of Lifting

A book mentioned by Greg as a deep-cut reference, offered as a prize to listeners who recognize a specific reference made by Lindsay.

The Future of Stronger by Science

An article published on the Stronger by Science website in November, detailing Greg's workload, content quality concerns, and the need for changes.

Do people really have 'fast metabolisms' or 'slow metabolisms'?

An article by Greg on the MacroFactor website, explaining that BMR variability is significant between individuals, primarily due to relative organ sizes.

Tools & Products

Petri dish

Used as an example of a setting where mechanistic research (e.g., knocking out a gene) might look promising but not always translate to real-world outcomes.

Studies & Research

Acasta-Mezario et al. 2020 Review

A systematic review and meta-analysis titled 'Beyond General Resistance Training: Hypertrophy versus Muscular Endurance Training as Therapeutic Interventions in Adults with Type 2 Diabetes Mellitus', which found that resistance training in diabetics still leads to muscle growth.

Ponser and colleagues' Constrained Energy Expenditure Model

A model suggesting a non-linear relationship between physical activity energy expenditure and total daily energy expenditure, where being very active limits the additional calories burned per increment of activity.

MASTERS Trial

A randomized controlled trial that studied the effects of Metformin on training adaptations, finding a negative impact on muscle growth despite initial optimism.

Bagotsky and colleagues' study (cited in 'Size vs. Strength')

Research referenced in the 'Size vs. Strength' article that modeled internal muscle moment arms, particularly in the biceps, explaining how increased muscle size can improve leverage.

Bonito et al. 2020 Meta-analysis

A systematic review with meta-analysis on resistance training effects on whole-body muscle growth in adult males, used for comparison with diabetic populations.

Supplements

Collagen supplementation

Mentioned as a research topic for its impact on skin aging, tendons, ligaments, and bone health, with potential overlapping pathways in synthesis.

People

Lee Peele

Hired as a full-time content person for MacroFactor, described as amazing and a well-known figure in the fitness industry.

Milo and Pac

Two new full-time hires for Stronger by Science, who will become Greg's co-hosts for the podcast, praised for their intelligence, talent, and expertise as researchers and science communicators.