Triathlon Training: What Is Sweet Spot Training?
SUMMARY
Sweet spot training targets the moderate-hard zone — around 75–85% max heart rate, 88–93% FTP, or RPE 6–7. It’s one of the most effective tools for triathletes to build strength, stamina and resilience without tipping into fatigue. This post breaks down how sweet spot training applies to swim, bike, and run, how to structure it across your plan, and why it helps you go longer, recover faster and stay consistent through every phase of triathlon prep.
What Is Sweet Spot Training?
Training for a triathlon is all about finding the right balance — pushing hard enough to improve, but not so hard that you burn out. That’s where sweet spot training comes in. It’s a strategic approach to building endurance, strength and race-day stamina without overloading your body.
Sweet spot training is based around moderate-hard intensity. You're working just below your threshold — tough enough to trigger adaptation, but manageable enough to recover quickly and stay consistent.
For most athletes, this effort level falls between:
75–85% of FTP (Functional Threshold Power) on the bike
80–90% of max heart rate for running
You can find your exact sweet spot range using FLJUGA’s free FTP and Heart Rate Calculators.
It’s not just a number. Sweet spot is a concept — a space where effort, reward, and sustainability meet. When used consistently, it builds resilience, aerobic capacity, and muscular endurance in all three triathlon disciplines.
Why Triathletes Should Use Sweet Spot Training
Triathlon is about going long and going strong. Whether you're racing Olympic distance or preparing for an Ironman, holding a steady effort under fatigue is what makes or breaks your performance. That’s why sweet spot training is such a powerful tool.
Here’s what makes it essential:
Efficient endurance gains: You improve stamina without excessive recovery needs.
Fatigue resistance: You teach your body to stay strong during long efforts.
Pacing control: You learn how to hold back slightly while still working hard — perfect for race execution.
Consistency: Less taxing than threshold or VO2 intervals, so you can train more often and stay on track.
Sweet spot training fits seamlessly into the base and build phases. During these stages, your focus is on sustainable volume, efficiency, and structural development — not all-out intensity. This is where sweet spot shines.
How to Add Sweet Spot to Your Triathlon Training
Here’s how sweet spot training looks in each discipline:
Cycling Sweet Spot Session
Cycling is the most common application of sweet spot work, especially when using power data. It's ideal for improving your functional threshold and aerobic efficiency. Sweet spot is most commonly used in cycling because it's easy to measure via power.
Warm-Up: 10–15 min easy spin
Main Set: 3 × 10 min @ 88–93% FTP (or Zone 3–4) (5 min easy spin between)
Cool-Down: 10 min easy spin
Progression Tip: Increase interval length to 2 × 20 min or 3 × 15 min as fitness builds.
Running Sweet Spot Session
Running at sweet spot effort builds strength and aerobic control — essential for steady pacing off the bike. Use heart rate or perceived exertion to guide intensity. You should be breathing steadily, with effort you can sustain for 45–60 minutes.
Warm-Up: 10 min easy jog
Main Set: 3 × 8 min @ 80–90% Max HR (RPE 6–7) (4 min easy jog between)
Cool-Down: 10 min easy run
Progression Tip: Increase to 2 × 15 min or 3 × 12 min as endurance improves.
Swimming Sweet Spot Session
In swimming, sweet spot builds aerobic swim strength while reinforcing pacing efficiency. Even in the water, sweet spot training teaches pacing efficiency under fatigue.
Warm-Up: 400m easy swim
Main Set: 4 × 200m @ moderate-hard effort (30 sec rest between each)
Cool-Down: 200m easy swim
Progression Tip: Increase to 3 × 300m or 2 × 400m for aerobic strength gains.
When to Add Sweet Spot Training to Your Plan
Sweet spot training isn’t an everyday tool — but it should be a staple part of your weekly structure.
Use it:
During Base & Build Phases
To develop aerobic strength and muscular durabilityWhen Time-Crunched
You get strong without spending hours recoveringIn Double Days
Use sweet spot in one session (e.g., AM bike) and recover with easy work later (e.g., PM run)When You’re Tired
If you're fatigued but still want value, sweet spot is more manageable than threshold or VO2In Periodized Progressions
Stack sweet spot blocks for 3–4 weeks, then step up intensity or duration
Aim for 1–2 sweet spot sessions weekly, alternating between disciplines depending on your current focus.
How to Stay in the Sweet Spot
To stay in the right training zone, use one of the following:
Heart Rate (Run & Bike)
Target 75–85% of your max heart rate (use FLJUGA’s HR calculator)Power (Bike)
Train at 88–93% of your FTPRPE (All sports)
Effort should feel like a 6 to 7 out of 10 — breathing is labored but sustainablePacing (Swim/Run)
Use pace benchmarks like CSS pace (swim) or a tempo pace you can hold for 45–60 minutes
Tracking these zones ensures you get the maximum benefit without slipping into a harder threshold zone.
Sweet Spot vs Threshold Training
Sweet spot training sits just below threshold — both are valuable, but they serve slightly different purposes in triathlon prep.
Intensity: Sweet spot is moderate-hard, while threshold is hard and closer to your sustainable maximum.
Recovery Time: Sweet spot workouts typically need 24–36 hours to recover from, whereas threshold sessions often require 48–72 hours.
Mental Load: Sweet spot is tough but manageable, making it easier to repeat consistently. Threshold carries a higher mental toll and needs more motivation to complete well.
Aerobic Efficiency: Sweet spot delivers excellent aerobic gains with lower stress. Threshold is also effective, but the recovery cost is higher.
Consistency Potential: You can include 1–2 sweet spot sessions each week reliably. Threshold is usually limited to once per week to avoid burnout.
Best Use: Sweet spot is ideal during base and build phases when you're focused on volume and durability. Threshold sessions are best used in sharpening phases as you approach race day.
FAQ: Sweet Spot Training for Triathletes
What is Sweet Spot training in triathlon?
It’s training at a moderate-hard effort — typically around Zone 3 to low Zone 4. It targets the ideal intersection of effort and sustainability. Use FLJUGA’s calculators to find your personal sweet spot zones.
Why is Sweet Spot training so effective?
It delivers strong aerobic and muscular adaptations without burning you out. This makes it perfect for consistent training and long-term gains.
Can beginners use Sweet Spot training?
Absolutely. It’s one of the best ways for newer athletes to get fit without going too hard too soon. Start with shorter efforts and build from there.
Is Sweet Spot only for cycling?
No. While it’s easiest to track in cycling using FTP, sweet spot applies to running and swimming too — anywhere you want to build sustained effort and pace control.
How often should I include Sweet Spot sessions?
Include 1–2 per week in your triathlon plan — usually in cycling or running. As your base builds, you can rotate sweet spot efforts across disciplines.
Final Thoughts
Sweet spot training is one of the smartest ways to build real-world race fitness. It’s not flashy — but it’s consistent, powerful, and effective. When you train in the sweet spot regularly, you develop strength that lasts through race day and recovery that keeps you on track week after week.
For triathletes, it’s a cornerstone. One that bridges the gap between long, slow base work and the high-pressure world of race-pace training. Find your sweet spot. Train in it. And watch your performance rise.
Train smart, stay consistent, and enjoy the journey!
Always consult with a medical professional or certified coach before beginning any new training program. The information provided is for educational purposes only and is not a substitute for personalized advice.
