Plain-English definitions for hybrid training terms

1RM is the maximum amount of weight that can be lifted once with proper technique.

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.

A chipper is a workout completed in a single round with a long sequence of exercises and high repetitions.

A cluster set is a training method that breaks a set into smaller segments with short rest periods between them.

A couplet is a workout format that combines two exercises performed together.

Death By is a workout format where reps increase each minute until the athlete can no longer complete the required work in time.

A drop set involves performing an exercise to failure, reducing the load, and continuing with minimal rest.

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.

For Time is a workout format where the goal is to complete a prescribed amount of work as quickly as possible.

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

A giant set is a training method where three or more exercises for the same muscle group are performed back-to-back with minimal rest.

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.

A ladder is a workout structure where repetitions increase or decrease in a set progression each round.

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.

Progressive overload is the practice of gradually increasing training stress to stimulate continued adaptation.

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

RIR is the number of additional quality repetitions an athlete could perform before muscular failure.

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.

Rx’d means completing a workout exactly as written, without scaling movements, loads, or standards.

Scaled means adjusting a workout’s load, volume, or movements to suit an athlete’s ability while maintaining intent.

A singlet is a workout format built around a single exercise or movement pattern.

A superset is a training method where two exercises are performed consecutively with minimal rest.

Tabata is a HIIT protocol of 20 seconds work and 10 seconds rest repeated for eight rounds.

A time cap is the maximum time permitted to complete a workout before it is stopped.

A triplet is a workout format that combines three exercises performed together.

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.