Interval Training vs. Tempo Runs: Which Builds Speed Faster?

Understanding the Mechanics of Speed

As a coach, I am frequently asked which method reigns supreme: intervals or tempo runs. The truth is that both are fundamental pillars of a high-performance running programme. To become a faster athlete, one must understand how different intensities influence your physiological adaptations. We are not just running; we are systematically dismantling your current limitations.

Interval training involves repeated bouts of high-intensity effort followed by periods of recovery. This method is designed to push your anaerobic threshold and improve your VO2 max. By running at speeds faster than your race pace, you teach your body to clear lactate more efficiently, allowing you to sustain higher intensities for longer durations.

Conversely, tempo runs, or lactate threshold runs, are performed at a 'comfortably hard' pace. This is typically the fastest pace you could maintain for about an hour. These sessions are essential for building your aerobic engine and improving your metabolic efficiency. It is the art of teaching your body to maintain a high speed before the onset of fatigue.

Will It Make me Faster

Interval training is your primary weapon for raw speed. By forcing your heart and lungs to operate at near-maximal capacity, you increase your stroke volume and capillary density. This improves your body's ability to transport oxygen to working muscles. If your goal is to shave seconds off your 5K or 10K time, intervals are non-negotiable.

Tempo runs, however, make you faster in a different way. They raise your lactate threshold, which is the ceiling of your sustainable performance. As you become more adept at these runs, your 'easy' pace naturally gets faster. You are essentially shifting your entire performance curve to the right, allowing you to run faster with less physiological stress.

How long before I see improvements

Patience is the athlete's greatest virtue. While you might feel a 'pop' in your legs after a single interval session, tangible aerobic adaptations take time. Generally, you can expect to see measurable improvements in your race times after six to eight weeks of consistent, periodised training. Do not rush the process; allow your tendons and ligaments to adapt to the increased load.

Consistency is the secret ingredient. A single hero session will not make you an Olympian, but a structured programme followed over a full training block will transform your performance. Prioritise recovery, nutrition, and sleep to ensure your body can absorb the training stimulus. If you neglect these, even the best interval programme will lead to burnout rather than a personal best.

To maximise your gains, alternate your weeks. Use one day for high-intensity intervals and another for a sustained tempo effort. This balanced approach ensures you are hitting both your top-end speed and your endurance threshold. Remember, the goal is to build a robust athlete who can handle the demands of race day without faltering.

Always warm up thoroughly before attempting high-intensity work. Dynamic stretches and light jogging will prepare your muscles for the explosive demands of intervals. Cooling down is equally vital to help flush out metabolic byproducts and initiate the recovery process. Treat your body with the respect it deserves as a high-performance machine.

Listen to your internal cues. If you feel excessive lethargy or persistent aches, it is time to reassess your intensity. A coach knows when to push and when to pull back. Speed is a byproduct of health; if you are constantly injured, you are not moving forward. Train smart, train hard, and the results will follow.

Finally, track your progress. Keep a detailed log of your splits, heart rate, and perceived exertion. Seeing the numbers improve over time provides the psychological boost needed to stay motivated through the tougher weeks of your training block. You have the potential; now you have the strategy.

10 alternative training techniques

1. Hill Repeats: Running uphill at a hard effort increases power and running economy. The incline forces you to lift your knees higher and engage your glutes, which translates to a more powerful stride on flat ground. It is a fantastic way to build strength without the high impact of sprinting on a track.
2. Fartlek Training: Derived from the Swedish word for 'speed play', this unstructured approach allows you to vary your pace throughout a run. By alternating between sprints to a landmark and recovery jogs, you develop a natural sense of pacing and learn to recover while still moving, which is vital for race scenarios.
3. Strides: These are short bursts of acceleration lasting 15 to 20 seconds. They focus on form, relaxation, and turnover rather than pure exhaustion. Incorporating strides at the end of an easy run helps to prime your neuromuscular system for faster speeds and improves your overall running efficiency without adding significant fatigue.
4. Long Runs: The cornerstone of endurance, the long run increases mitochondrial density and improves fat oxidation. By spending more time on your feet at an easy pace, you train your body to store more glycogen and become more efficient, which provides the foundation upon which your speed work can safely be built.
5. Plyometrics: Exercises like box jumps and bounding improve your explosive power and reactivity. By strengthening your tendons and improving your ability to store and release elastic energy, you become more efficient with every foot strike. This leads to a longer, more powerful stride that does not require extra muscular effort.
6. Threshold Intervals: These are longer than standard speed intervals but performed at a slightly slower intensity. By staying right at your lactate threshold, you train your body to clear lactate efficiently over extended periods. This is perfect for marathon runners who need to sustain a high speed for several hours at a time.
7. Progression Runs: Start your run at an easy pace and gradually increase the speed until you are finishing at a hard effort. This teaches you to run fast when your legs are already tired, mimicking the sensation of the final kilometres of a race. It is a brilliant mental and physical conditioning tool.
8. Circuit Training: Incorporating bodyweight strength exercises into your routine improves stability and core strength. A strong core prevents form breakdown during the latter stages of a race, ensuring that you maintain your speed even when your primary running muscles begin to fatigue. It is essential for injury prevention as well.
9. Recovery Runs: These should be performed at a very easy, conversational pace. The objective is to increase blood flow to the muscles to aid in the removal of waste products and promote tissue repair. Skipping these can lead to chronic fatigue and prevent you from hitting your target paces during hard sessions.
10. Cross-Training: Cycling or swimming allows you to maintain your aerobic fitness while giving your joints a break from the impact of running. This is an excellent way to increase your total training volume without the risk of overtraining or overuse injuries, keeping you consistent throughout your entire competitive season.