What makes you dizzy after one heavy lift but able to run for miles?

Your body has two distinct ways of creating energy—and understanding them changes how you train. In this episode, Clayton and Jennie explain aerobic versus anaerobic training, why both matter for real-world fitness, and how to balance them without sabotaging your results.

What We Cover:

Defining the Terms

Anaerobic training: Short, intense efforts (sprints, heavy lifts) that generate energy without oxygen using sugars stored in muscles and liver

Aerobic training: Longer, sustainable efforts (distance running, rowing) that use oxygen to fuel movement

Why your body needs both systems and what happens when you only train one

The Three Energy Pathways

Phosphocreatine pathway: Fuels explosive, high-intensity work (seconds)

Glycolytic pathway: Powers efforts up to about 2 minutes (like a 7-minute workout at moderate intensity)

Oxidative pathway: Sustains longer aerobic efforts (30+ minutes)

How these pathways overlap and work together during mixed workouts

Does Cardio Steal Your Gains?

What people actually mean by "gains" (muscle size, strength, or general fitness)

How your body adapts to the type of training you prioritize

Real example: A distance runner who got dizzy lifting moderate weight because his body had adapted entirely to aerobic work

The role of nutrition and recovery in supporting both types of training

Muscle Fiber Adaptation

Type 1 fibers (fast-twitch): Built for explosive, powerful movements

Type 2 fibers (slow-twitch): Built for endurance and sustained effort

How unbalanced training can shift your muscle fiber composition

Why Jennie could deadlift heavy while marathon training—and why her lifts suffered after a 20-mile run

Injury Prevention and Well-Rounded Fitness

Jennie's experience: Running-only training led to injuries when she tried explosive work

Why preparing for "whatever life brings" requires training both systems

The importance of eating carbohydrates to fuel anaerobic work

How to think about programming when you have specific goals (marathon training, powerlifting, general fitness)

Key Takeaways:

Your body doesn't flip a switch from one energy system to another—they overlap and blend

You can train both aerobic and anaerobic systems successfully with balanced programming and proper nutrition

Focusing exclusively on one type of training limits your overall fitness and increases injury risk

What matters most: matching your training to your goals while maintaining enough balance to stay resilient

Resources:

https://timberandsteelgym.com/podcast/what-is-fitness-part-1

Final Thoughts:

Whether you're chasing a PR on your deadlift or training for a half marathon, the answer isn't choosing between aerobic and anaerobic training. It's understanding how both systems serve you and structuring your program to develop the fitness you actually need. As Jennie puts it: "You need them both for a well-rounded, balanced body."