THE SCIENCE
HIIT and Performance Benefits
The most important adaptations associated with high-intensity interval training include:
- increase in VO₂max
- improvement in cardiac output and stroke volume
- improvement in oxygen transport and utilization capacity
- increased tolerance to high intensities
- improvement in neuromuscular function and movement economy at high speed
At the same time, the alternation between intensity and recovery allows the athlete to remain at higher intensities than those that can be sustained during a continuous steady-state effort.
The cumulative duration of this stress creates a strong training stimulus for performance improvement.
The effectiveness of HIIT, beyond its association with high intensity itself, promotes the proper balance between repetition duration, intensity, and recovery.
According to the literature, high-intensity interval training represents one of the strongest mechanisms for improving aerobic capacity and competitive performance in endurance athletes.
HIIT and Endurance Performance:
VO₂max (VO₂peak) in elite athletes under high-intensity interval training: A meta-analysis
THE APPLICATION
How Interval Training Should be Properly Applied
Interval training has a specific structure that determines both the physiological stimulus and the quality of the expected adaptations that will occur.
Therefore, it is not simply about performing fast repetitions.
In practice, the goal is not exhaustion, but the accumulation of quality time at high intensity with controlled metabolic cost.
BASIC VO₂max TRAINING FORMATS
Medium-Duration Repetitions
- 4–8 × 1000
- at an intensity close to VO₂max
- with recovery that allows maintenance of effort quality in each repetition
This type of training allows significant cumulative time at high intensity, without performance decline between repetitions.
STRUCTURED RECOVERY
Recovery between repetitions is a crucial part of the training stimulus and not a “passive” component of the session.
Its duration affects:
- maintenance of intensit
- physiological stress
- the overall quality of the training session
Insufficient recovery may lead to premature pace decline and loss of the intended training objective, while excessively long recovery duration may reduce the overall physiological stress and alter the desired training stimulus.
KEY PRINCIPLES OF APPLICATION
Interval training should:
- be performed 1–2 times per week
- be scheduled on days with adequate recovery before and after
- maintain high execution quality throughout the session
CRITICAL POINT
High intensity should not be confused with uncontrolled stress.
Excessive intensity:
- disproportionately increases metabolic cost
- affects movement mechanics
- reduces training quality
- increases recovery time
COACHING PRINCIPLE
Interval training aims to sustain high intensity with controlled physiological cost and not uncontrolled fatigue.
Essentially, this type of training represents the mechanism through which high intensity is transformed into functional adaptation and competitive performance.
VO₂max Workouts and Endurance Adaptation:
Dimitrios Theodorakakos
Sports Director @sportsexcellence
Sports Excellence Team