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Oxygen is the most important molecule for endurance performance! | #38 ft. Dr. Robert A. Jacobs


This episode of the Critical Oxygen podcast explores the importance of oxygen in human performance. Dr. Robert Jacobs and I explore the role of mitochondria in energy production, the transfer of electrons and protons, and the process of ATP synthesis. The relationship between oxygen and other energy systems, such as phosphocreatine and glycolysis, is also discussed. The episode highlights the need for a balance between mitochondrial volume density and contractile proteins, as well as the adaptations that occur with different types of training. The role of mitochondria in fatigue reduction and the benefits of high mitochondrial volume density and function are also explored. This conversation explores the distribution of energy systems within cells, the importance of capillary density and mitochondrial volume density, and the potential benefits of supplementing with creatine for endurance athletes.


1) Oxygen is the most important molecule for endurance performance and life as we know it.

2) Mitochondria play a crucial role in energy production and the transfer of electrons and protons.

3) Training can lead to adaptations in mitochondrial volume density and function.

4) Developing capillary density and mitochondrial volume density should be a priority for endurance athletes.

5) Supplementing with creatine can aid in recovery and improve strength and some aspects of performance for endurance athletes.Enjoying these podcasts?

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00:00 Introduction and Importance of Oxygen

02:19 The Origin Story of Critical Oxygen

03:42 The Role of Mitochondria in Performance

05:11 Understanding the Powerhouse of the Cell

06:05 The Energy Transfer Process

08:28 The Importance of Oxygen as an Electron Acceptor

10:18 The Role of Oxygen in Energy Transfer

11:47 The Majority of Oxygen Utilization during Exercise

12:45 The Electron and Proton Transfer Process

14:44 The Role of Substrates in Energy Production

17:07 Understanding Oxidation and Electron Transfer

20:31 The Electrochemical Gradient and Proton Motive Force

23:03 The Inner Mitochondrial Membrane and Cristae

25:01 ATP Synthesis and the Mechanical Energy of

ATP Synthase 27:44 The Role of Phosphocreatine and Glycolysis

35:26 The Relationship Between Oxygen and Energy Systems

38:14 The Optimal Balance of Mitochondria and Contractile Proteins

41:36 The Adaptations from Zone 2 and High-Intensity Interval Training

49:04 The Collective Activation of Energy Systems

52:03 The Role of Mitochondria in Fatigue Reduction

53:53 The Benefits of High Mitochondrial Volume Density and Function

54:50 Distribution of Energy Systems within Cells

57:20 Importance of Capillary Density and Mitochondrial Volume Density

58:16 Supplementing with Creatine

01:00:14 Effects of Creatine on Endurance Performance

01:01:13 Benefits of Creatine for Recovery and Consistency

01:02:11 Additional Benefits of Creatine

01:06:00 Phosphocreatine Pool and Mitochondrial Function

01:07:18 Loss of Phosphocreatine during Exercise

01:09:43 Supplementing with Creatine for Endurance Athletes

01:10:12 Strength Training and Force Output

01:12:56 Oxygen as the Most Important Molecule

01:13:26 Closing Remarks and Call to Action

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