Plain-English definitions for hybrid training terms

Aerobic Base is the level of aerobic fitness that allows an athlete to sustain steady effort, recover efficiently, and support higher-intensity training.

AMRAP means completing as many rounds or repetitions of a workout as possible within a fixed time limit.

Carbohydrate availability describes how much stored and circulating carbohydrate is accessible to fuel exercise.

Central fatigue is a reduction in performance caused by decreased drive from the brain and nervous system.

EMOM means performing a set amount of work at the start of every minute, resting for the remainder of the minute before repeating.

Energy systems are the biological processes that supply the body with energy to perform movement and exercise.

Fat oxidation is the process by which the body breaks down fat to produce energy during rest and exercise.

Fuel utilisation describes how the body uses carbohydrates and fats to meet energy demands during exercise.

Glycogen is the stored form of carbohydrate in muscles and the liver used to fuel exercise.

Glycolysis is the process by which glucose is broken down to rapidly produce energy for muscular work.

Hormonal adaptation describes how hormone responses change over time in response to repeated training stress.

HRV measures the variation in time between heartbeats and reflects how well the body is recovering and adapting to stress.

Insulin sensitivity is how effectively the body uses insulin to manage blood glucose and deliver energy to cells.

Lactate Threshold is the highest exercise intensity that can be sustained before lactate accumulates faster than the body can clear it.

Mechanical Efficiency is the ability to convert energy into effective movement with minimal wasted motion.

Metabolic flexibility is the ability to shift efficiently between fat and carbohydrate use based on energy demands.

Recovery capacity is the ability to recover from physical and mental stress so performance can be repeated consistently.

RPE is a scale used to describe how hard an exercise feels based on personal effort rather than external metrics.

Running Economy refers to how much energy or oxygen a runner uses to maintain a given running speed.

Ventilatory Threshold is the exercise intensity at which breathing increases faster than workload due to rising metabolic demand.

VO₂ Max is the maximum rate at which the body can take in and use oxygen during intense exercise.

A WOD is the prescribed workout assigned for a specific training session.

Zone 2 training is sustained low-intensity exercise performed at an effort that can be maintained comfortably for long periods.