Long or Short Workouts: What's Best for Endurance Training?

For most athletes, endurance sports often mean logging countless hours of continuous training—day after day, week after week, season after season—all in pursuit of peak performance.

Over time, however, results tend to plateau or even decline. In response, many athletes increase training volume, hoping it will improve their endurance. Unfortunately, logging endless miles can actually be counterproductive. It may reduce an athlete’s ability to handle high-intensity efforts or develop speed. In endurance sports, aerobic capacity is crucial, but spending too much time at low intensities can hinder progress near maximum levels, such as VO₂max.

How Do You Measure the Right Effort?

Endurance volume is only effective if done at a specific intensity—below the aerobic threshold (approximately 2 mmol of lactate). Without clearly identifying this training zone, athletes risk misallocating their training intensity. Studies suggest that athletes spend only about 50% of their time in the correct zones. The rest of the time may be spent in energy systems that simply maintain, rather than improve, current capacities.

To properly define these zones and understand your current physiological state, it’s essential to do a physiological test based on speed (km/h, min per 100 m, or min/km) or power output (watts).

While there are generalized mathematical formulas to estimate training zones, these lack individual precision. They’re based on population averages, not personal physiological data—another reason why only half of training is effectively targeted.

Intensity Polarization: Very Low or Very High?

According to modern periodization principles, endurance programs should ideally follow an 80/20 model:

• 80% of training at low intensity (under 2 mmol of lactate)

• 20% at high intensity (approaching 4 mmol)

Low-intensity endurance training often feels too slow for confident athletes. But this is a common trap. These lower zones are crucial for improving metabolic efficiency and enhancing recovery. Correctly identifying and respecting intensity zones helps prevent burnout and overtraining while boosting long-term gains.

Triathlon: Three Sports, One Cardiovascular Engine

In triathlon, all three sports—swimming, cycling, and running—rely on the same cardiovascular system, although each requires different velocities or power outputs. There is crossover benefit between sports, especially for endurance development. Still, the muscular and mechanical execution (speed, power, technique) is sport-specific.

So, are high-intensity workouts transferable across sports? Yes—but with limitations. While cardiovascular benefits can carry over, muscular adaptations and movement patterns remain unique to each sport.

In Conclusion

To get the most out of your triathlon training time:

• Get your training zones evaluated professionally.

• Stick to them consistently to optimize both performance and recovery.