Building an Engine: How Interval Training Transforms Fitness and Performance | Pac Gym Porirua

Pac Gym
Jan 20
2 min read

When people talk about fitness, they often mean looking leaner or lifting heavier. But true fitness goes deeper. It is about building an engine that can handle anything. That is where interval training comes in.

At Pac Gym, we use interval work to push both endurance and power. It is not random. It is structured. And the science behind it is clear: training in intervals develops cardiovascular capacity, muscular endurance, and efficiency under fatigue.

What Is Interval Training?

Interval training is alternating periods of work and rest. That could mean:

60 seconds of rowing followed by 30 seconds of rest
A 400m run at pace then walking 200m before repeating
40 seconds of bike sprints then 20 seconds off

The method is simple. Push hard, recover, repeat. But the benefits go far beyond sweat.

Why Interval Training Works

1. Boosts aerobic and anaerobic capacity. Studies show interval training improves both VO₂ max (your body’s ability to use oxygen) and anaerobic threshold (how long you can work before fatigue takes over). In plain terms: you can go harder, for longer.

2. Builds efficiency under fatigue/ Fatigue exposes bad mechanics. By programming intervals, athletes learn to hold form under pressure whether that is rowing, running, or moving a barbell.

3. Burns more energy even at rest. High-intensity interval training (HIIT) elevates excess post-exercise oxygen consumption (EPOC). That is the “afterburn effect,” where your body continues burning energy long after the workout is over.

4. Transfers to real life and sport. Whether it is rugby, hiking, or just carrying the groceries, most of life happens in bursts of effort. Interval training builds the capacity to surge, recover, and go again.

How We Use It at Pac Gym Porirua to Build Engine

At Pac, we build interval training into our Engine classes. You will see work across different time domains:

Short, sharp bursts for power (20–40 second sprints)
Threshold efforts to sustain pace (2–5 minutes of controlled intensity)
Longer intervals to condition your aerobic base (6–10 minutes steady, repeatable work)

We rotate through machines (rower, bike, ski), running, and functional movements. This is not guesswork. It is structured programming designed to build an engine that holds up in training, competition, and life.