Testosterone

S2E44: Effect of Caffeine Intake on Muscle Strength and Power w Jozo Grgic PhD

SEASON 2, EPISODE #44

Dr. Bubbs sits down with expert Jozo Grgic PhD, to talk about the effects of caffeine intake on resistance training. Jozo outlines the mechanisms of how caffeine may impact strength and power-based training, lower-body versus upper-body movements, as well as its effects on pain and hormone response to training. He also discusses the caffeine dose ranges, coffee versus caffeine supplements, what the research says for female athletes and the effects of caffeine gum on performance. Jozo also shares how caffeine impacts blood pressure and his thoughts on the evolution of caffeine research.

Summary of Episode

3:00 – The mechanisms of how caffeine impacts resistance exercise

5:00 – The effects of caffeine on power-based exercises and lower-body versus upper-body movements.

9:00 – Rate of perceived exertion and resistance vs. endurance training

12:00 – Caffeine effects on pain during resistance exercise

13:30 – Caffeine’s effects on testosterone and cortisol post-training

14:45 – Caffeine dosing for resistance training

18:45 – Caffeine intake in female resistance training

22:00 – Coffee vs. caffeine for resistance training

28:30 – Caffeine washout period and the amount of caffeine in your coffee (vs. published literature).

30:00 – Chewing gum and speed of caffeine uptake

32:30 – Impacts of caffeine on blood pressure

About Jozo Grgic

A researcher from Croatia with a Masters degree in exercise science, Jozo is currently doing his PhD in exercise science and exercise physiology (with a focus on the effects of caffeine supplementation on exercise performance) at Victoria University, Melbourne. Jozo has co-authored around 30 peer-reviewed papers (many collaborations with Brad Schoenfeld) with a special focus on resistance exercise prescription and caffeine supplementation. Follow Jozo on Twitter @Jozo_Grgic .

Research Papers

Caffeine ingestion acutely enhances muscular strength and power but not muscular endurance in resistance-trained men

Effects of caffeine intake on muscle strength and power: a systematic review and meta-analysis


S2E30: Muscle Science: Training to Failure, Testosterone & The Soy Controversy w Dr. Cody Haun PhD

SEASON 2, EPISODE #30

Dr. Bubbs sits down with hypertrophy and muscle science expert Dr. Cody Haun PhD. In this episode, Cody will discuss a few of his recent papers, starting with recovery responses to light versus heavy resistance exercise in young men and unpacking what's happening at the molecular level between light and heavy loads. Next, Cody shares the results and key findings from his research on high versus low responders to training, the biomarkers associated with low, moderate, and high responders to training. Finally, Cody addresses the soy protein controversy around supplementation and testosterone. Does it impact estrogen level? Does it impact fat accumulation? Fantastic insights from Cody.


S2E11: Assessing Body Composition, Performance Metrics & Biomarkers w/ Dr. Shawn Arent PhD

SEASON 2, EPISODE #11

Dr. Bubbs interviews Dr. Shawn Arent PhD, Director of the Center for Health & Human Performance at Rutgers University. Shawn dives into why body composition testing is important for athletes, compares DEXA/Bodpod/BIA/Calipers, and talks about the importance of consistency and tracking. He also discusses the use of performance metrics to assess athlete development and then take a deep dive into lab biomarkers for health and performance. Great stuff from one of the absolute best in the game!

About Dr. Shawn Arent PhD

Shawn is the Director of the Center for Health & Human Performance at Rutgers University and the current President of the International Society of Sports Nutrition. Shawn’s also a fellow in the American College of Sports Medicine and the recipient of a Presidential Fellowship for Teaching Excellence. His research focuses on the relationship between physical activity and stress and the implications for health and performance. Follow Shawn on Twitter, and stay up-to-date with The Rutgers Center for Health and Human Performance.

Research Links

Workload, Energy Expenditure, and Biomarker Differences in Division I Male and Female Soccer Players: 2078 Board #91 June 1 3

Workload-related Psychological And Physiological Changes In Female College Soccer Players During A Competitive Season: 2096 Board #109 June 1 3 

Shawn’s “Big Rocks”

Take stock in “why” you want to make a change; what is the underlying reason behind that reason. Take the time to peel back the layers to find out.

S2E6: Nutrition For Bodybuilders, Hypertrophy and Physique-Focused Athletes w Dr. Eric Helms PhD

SEASON 2, EPISODE #6

Dr. Bubbs chats with expert strength and hypertrophy researcher Dr. Eric Helms PhD to talk nutritional strategies for bodybuilders and physique-focused athletes.  In this episode, Eric outlines how protein requirements shift depending on training phase, effective weekly targets for weight loss, the key role of carbohydrates for bodybuilders and suggested intake ranges, as well as how contest prep impacts testosterone levels, evidence-based supplements to potentially add to your arsenal and the importance of using your eyes and ears to monitor progress.


About Dr. Eric Helms

An active researcher in the areas of maximum strength development, fat loss, hypertrophy and competitive physique and strength sport. He is the co-founder and regular contributor to the Monthly Applications in Strength Sport research review and is the author of the Muscle & Strength Nutrition and Training Pyramids books. Eric also coaches a handful of drug free strength and physique athletes through 3D Muscle Journey LLC, which he co-founded in 2009.


Research Link

Evidence-based recommendations for natural bodybuilding contest preparation: Nutrition and supplementation. May 2014 Journal of the International Society of Sports Nutrition 11(1):20