Revolutionise Your Training: The Secret Sprint Training Advantage to Ultra Runners

Integrating sprint training can offer a multitude of benefits that can significantly enhance performance in as little as 6 sessions. Yes, you read that right, 6 sessions.

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For endurance athletes, especially those in ultra running, the idea of incorporating sprint training might seem counterintuitive. After all, isn’t endurance built through long, slow distance runs? While that certainly has its place in every successful ultra runner’s programme, integrating sprint training can offer a multitude of benefits that can significantly enhance performance in as little as 6 sessions. Yes, you read that right, 6 sessions.

The Science

Let’s start with the physiological principles. Contrary to popular belief, endurance isn’t solely determined by aerobic capacity; it also relies on anaerobic power and efficiency. So we have a clear understanding of this section, It’s important to know the following:

Aerobic Energy System:

– Relies on oxygen to produce energy.

– Provides sustained energy over longer durations, such as in endurance activities like marathon running, through the breakdown of carbohydrates and fats.

Anaerobic Energy System:

– Operates without oxygen, relying on stored energy sources like ATP and creatine phosphate.

– Generates quick bursts of energy for high-intensity activities, such as sprinting or weightlifting, but fatigues rapidly compared to aerobic metabolism.

Sprint training targets anaerobic energy systems. The amazing thing about it though is that, despite its emphasis on anaerobic bursts, sprint training also exerts a profound influence on aerobic efficiency. Research exploring the impact of sprint training on aerobic adaptations, shows its capacity to build mitochondrial density and oxidative enzyme activity, thereby amplifying a runner’s capacity for sustained aerobic efforts. It also enhances glycolytic enzyme activity and phosphocreatine resynthesis, thereby improving the body’s capacity for rapid energy production and muscular force generation.

In simple terms, your body is a wonderful vessel that tends to adapt to whatever stimulus you give it consistently. When racing and performing, ultra runners need to be more adaptable than most think. Incorporating this type of training will improve your performance across the board, your body will also take the energy you feed it and use it efficiently. With a considered approach and consistency, this will directly improve performance and result in dramatic improvement to your running. Science shows it time and time again.

The Main Goal: Fostering Performance Adaptability

Every ultra runner, whether in the race to compete or complete, needs to be metabolically dynamic and physically adaptable to consistently perform well in races. Sprint training promotes metabolic versatility, enabling runners to seamlessly transition between energy substrates in response to shifting physiological demands. Research into this type of training shows a number of things, but mainly an enhancement in a runner’s metabolic repertoire which facilitates sustained performance across varying terrains and intensities. That is the stuff dreams are made of for us ultra runners.


The Blueprint for Your Training

“All right Kris, you have thrown some science at us and have my attention, just show me what I have to do before you bore me to death,” I hear you shout. Alright, alright, here you go.

Sample Workouts:


1. Max Effort Intervals:

   – Warm up with 10-15 minutes of easy jogging.

   – Perform 4-6 Reps of 200-metre repeats at 90-95% of maximum effort, with 2-3 minutes of active recovery (easy jogging or walking) between sets.

   – Cool down with 10-15 minutes of easy jogging and dynamic stretching.


2. Hill Sprints:

   – Find a moderate to steep incline (6-8% gradient).

   – Perform 6-8 sets of 20-30 second uphill sprints at maximum effort, focusing on powerful, explosive strides.

   – Walk down the hill for recovery between sprints.

   – Finish with a brief cool down jog


3. Tabata Intervals:

   – Warm up with 10-15 minutes of easy jogging.

   – Alternate 30 seconds of maximum effort sprinting with 90 seconds of rest, repeated for a total of 8 reps. Then rest completely for 5 minutes before repeating a second set.

   – Cool down with 10 minutes of easy jogging.

Progression: It is important to do it correctly. 

At this stage of the article, I need to hammer home this point.  

Sprint training isn’t about pacing yourself strategically. It’s about unleashing raw power and speed with each and every rep. This mindset shift is crucial. In sprint training, you’re not conserving energy for the long haul; you’re giving it your all in short bursts of intensity.

Moreover, maintaining a low number of reps with maximal effort is key to reaping the rewards. Each sprint should be treated as a quality rep, focusing on the desired adaptation. Resist the temptation to add more reps as you progress. Instead, keep the reps low and the effort maximal to prevent fatigue-induced declines in performance and to maintain the quality of each sprint. The final few seconds of each rep are arguably the most important. 

Maximising Your Personal Performance: Key Considerations

While you have “fun” with this new type of training, it’s essential to approach it strategically to maximise results whilst minimising the risk of injury or overtraining. Here are some key considerations depending on your current training:

Progression – Gradually increase the intensity and volume of sprint training sessions to allow for adaptation and reduce the risk of injury, especially if you are new to it. Start with one session a week and build to two or three as your training volume grows.

Recovery – Prioritise adequate rest and recovery between sprint sessions to allow for optimal adaptation and performance gains. Do not follow a sprint session with a hard or threshold run or vice versa. As you develop, you should be able to take an easy run within 12 hours of a sprint session but you should factor in a 24-hour recovery period.

Form and Technique – Focus on proper running mechanics during sprinting to maximise efficiency and reduce the risk of injury. Knee drive is important, we will cover form in a separate article.

Before you go, If you are not sold yet, here is some bonus science.

Accelerated Recovery

Whilst traditional endurance workouts often need extended recovery periods, sprint training offers a stark departure with its shorter recovery demands. Research also explored the impact of short-duration, high-intensity interval training on recovery times, revealing accelerated physiological adaptations without compromising endurance gains. It seems that by virtue of its condensed nature, sprint training gives ultra runners the ability to improve training frequency, which results in consistent progress while minimising downtime.

With careful planning, progression, consistency, and attention to recovery, you now know something that the vast majority of ultra runners don’t. Use this information wisely to get the results you deserve. 

May your future be full of Personal Bests and race wins. I would love to hear about them.

Now, let’s get at it

Kris King

See an example sprint session in action by clicking the image down below!

Follow Kris on Instagram for more training tips:   / kris_kingy  

Check out Jon’s socials here:   / jon_shield_runs_ultras  


For some added learning here is a quick glossary of some terms used in the article and references to research below. 

Mitochondrial density: Refers to the concentration or abundance of mitochondria within a cell or tissue. Mitochondria are organelles responsible for energy production in cells through oxidative phosphorylation. Higher mitochondrial density often correlates with increased aerobic capacity and endurance.

Oxidative enzyme activity: Enzymes involved in oxidative metabolism, particularly within the mitochondria, where they facilitate the breakdown of substrates to produce energy through oxidative phosphorylation. Examples include enzymes like cytochrome c oxidase, succinate dehydrogenase, and NADH dehydrogenase.

Glycolytic enzyme activity: Enzymes involved in glycolysis, the metabolic pathway that breaks down glucose into pyruvate, producing ATP and NADH. Glycolytic enzymes include hexokinase, phosphofructokinase, and pyruvate kinase. This pathway is important for energy production in the absence of oxygen (anaerobic conditions) and during high-intensity exercise.

Phosphocreatine resynthesis: Refers to the regeneration of phosphocreatine (PCr) within muscle cells. Phosphocreatine is an important energy buffer in cells, especially during short bursts of high-intensity activity, such as sprinting or weightlifting. After depletion of PCr stores during exercise, resynthesis occurs during rest or low-intensity activity, replenishing the cell’s energy reserves.


– Laursen, P. B., & Jenkins, D. G. (2002). *Journal of Strength and Conditioning Research, 16*(3), 429-438.

– Yamamoto, L. M., Lopez, R. M., Klau, J. F., Casa, D. J., Kraemer, W. J., & Maresh, C. M. (2008). *Journal of Strength and Conditioning Research, 22*(4), 1141-1149.

– Burgomaster, K. A., Hughes, S. C., Heigenhauser, G. J., Bradwell, S. N., & Gibala, M. J. (2005). *Journal of Applied Physiology, 98*(6), 1985-1990.

-Gibala, M. J., Little, J. P., van Essen, M., Wilkin, G. P., Burgomaster, K. A., Safdar, A., … & Tarnopolsky, M. A. (2006). Journal of Physiology, 575(3), 901-911.

-Tabata, I., Nishimura, K., Kouzaki, M., Hirai, Y., Ogita, F., Miyachi, M., & Yamamoto, K. (1996). Medicine & Science in Sports & Exercise, 28(10), 1327-1330.

– Hickson, R. C., Bomze, H. A., Holloszy, J. O., & Dover, E. D. (1977). *Medicine and science in sports*, 9(4), 191-195.

About the Author

Kris King

For two decades, Kris has been an industry-leading mind on this grueling sport, having run ultra marathons, coached others to complete them, and designed some of the toughest races in the world.
Kris is the owner and director of Beyond the Ultimate, a company that organizes multi-day ultra marathons in some of the world's most breathtaking locations. He has been featured in numerous publications and has shared his expertise at conferences and events around the world.

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