Many endurance athletes know they should include strength training, but far fewer understand how their strength training should change throughout the season.
One of the biggest mistakes I see is athletes using exactly the same gym programme every week of the year. They might gradually increase the weight they lift, but the exercises, repetitions and training focus never change. While this is certainly better than doing no strength training at all, it isn’t the most effective way to improve performance.
Just as your swim, bike and run training changes throughout the year, so too should your strength training.
A simple four-phase periodised approach allows you to build a solid foundation, develop strength, convert that strength into sport-specific performance, and maintain your gains when race day approaches.
Why Periodise Strength Training?
The purpose of periodisation is simple: to help you perform at your best when it matters most.
Rather than trying to improve every physical quality at the same time, each phase has a specific objective that prepares you for the next stage of training.
By progressing through each phase, you’ll:
- Improve your strength safely.
- Reduce your risk of injury.
- Support your endurance training.
- Arrive at your key event stronger and more resilient.
The key is ensuring your strength programme complements your endurance training rather than competing with it.
Phase 1: Strength Endurance
The first phase focuses on building the foundation for everything that follows.
The goal is to develop muscular endurance, improve work capacity, and strengthen the muscles, tendons and connective tissues that will cope with increasing training loads later in the season.
During this phase you should:
- Use lighter weights.
- Perform higher repetitions.
- Focus on excellent movement technique.
- Control every repetition, particularly the lowering phase of each lift.
This phase isn’t about lifting the heaviest weight possible. Instead, it’s about preparing your body for the heavier work to come.
Phase 2: Basic Strength
Once you’ve established a solid foundation, it’s time to increase the load.
The objective of the Basic Strength phase is to develop maximum strength through heavier resistance and lower repetitions.
Although you won’t use this level of strength directly during a half marathon or an Ironman, it provides the foundation that supports your endurance performance.
Benefits include:
- Greater force production.
- Improved movement efficiency.
- Better neuromuscular coordination.
- Increased resilience under fatigue.
This phase is where many endurance athletes make significant performance gains.
Phase 3: Specific Power
Strength alone isn’t enough.
The next step is learning how to apply that strength to your sport.
The Specific Power phase focuses on faster, more explosive movements that closely resemble the demands of running, cycling or triathlon.
Exercises may include:
- Plyometric drills.
- Hill sprints.
- Bounding.
- Explosive step-ups.
- Multi-directional lunges.
- Medicine ball exercises.
Training volume generally decreases, while movement speed increases.
The goal is to convert the strength you’ve developed into improved athletic performance.
Phase 4: Strength Maintenance
As your key race approaches, your endurance training becomes the priority.
That doesn’t mean strength training stops.
Instead, you reduce the amount of gym work while maintaining the quality of the sessions.
Strength Maintenance helps you:
- Retain the gains you’ve worked hard to achieve.
- Reduce fatigue.
- Minimise muscle soreness.
- Continue supporting your endurance performance throughout the racing season.
Many athletes make the mistake of stopping strength training altogether before an important race. In most cases, maintaining one quality session each week is enough to preserve your strength without compromising recovery.
How the Four Phases Fit Together
A typical endurance season might look something like this:
| Endurance Training Phase | Strength Training Phase |
|---|---|
| Foundation & Injury Prevention | Strength Endurance |
| Early Quality | Basic Strength |
| Transition Quality | Specific Power |
| Final Quality & Racing | Strength Maintenance |
While the exact timing will vary depending on your event and training plan, the progression remains the same.
Each phase prepares you for the next.
Common Mistakes
There are three mistakes I see most often:
Using the same gym programme all year.
Your body adapts quickly. If your programme never changes, your progress eventually stalls.
Progressing too quickly.
Trying to lift heavy before you’ve built an adequate foundation often leads to poor technique, excessive fatigue or injury.
Stopping strength training before race day.
Reducing volume is appropriate, but abandoning strength work altogether means losing some of the adaptations you’ve spent months developing.
Final Thoughts
Strength training isn’t simply about becoming stronger in the gym.
It’s about becoming a better endurance athlete.
By progressing through Strength Endurance, Basic Strength, Specific Power, and Strength Maintenance, you’ll ensure your gym work supports your running, cycling or triathlon goals throughout the season.
A structured approach not only improves performance but also helps you stay healthier, recover better and arrive at your most important events ready to perform.
If you’re serious about improving your endurance performance, don’t just periodise your swim, bike and run training—periodise your strength training too.
Should You Be Doing Strength Training in the First Place?
Before you start planning how to periodise your strength training, it’s worth asking an even more important question: Do you actually need strength training? The answer isn’t always as straightforward as many people think. While strength training can improve performance, reduce injury risk and support healthy ageing, it also comes with an opportunity cost. Every hour spent in the gym is an hour not spent swimming, cycling, running, recovering or sleeping. For many recreational endurance athletes, those activities may provide a greater return on investment if time is limited.
That’s exactly what I explore in my earlier article, “Do Endurance Athletes Really Need Strength Training?” Rather than assuming every athlete should lift weights, I discuss when strength training is likely to provide the biggest benefits, when sport-specific training should take priority, and how to decide whether strength work is the best use of your available training time. Once you’ve determined that strength training deserves a place in your programme, this article provides the next step: how to structure it throughout the season using a simple four-phase periodised approach. Read the companion article here:
Ready for a Structured Training Plan?
If you’d like your endurance and strength training planned together, my coaching programmes remove the guesswork by showing you exactly what to do, when to do it, and why.
Whether you’re training for a half marathon, marathon, triathlon or Ironman 70.3, you’ll receive a periodised programme designed to help you become stronger, more resilient and perform at your best on race day.
If you’d like to discuss a suitable strength training plan for your situation, feel free to book a consultation: