Training Stress Score: The Metric That Changed Cycling Forever

Posted on by Hunter Allen

When power meters first hit cycling, we suddenly had more data than ever before. Watts, cadence, heart rate, all valuable, but overwhelming. We needed a way to make sense of it. That’s where Training Stress Score (TSS) came in.

TSS revolutionized coaching. It gave us a single number that quantified training load, balancing intensity and duration. Today, it’s one of the most powerful tools we have to prevent burnout, manage progress, and peak at the right time.

Dr. Andrew R. Coggan and I did not set out to create a metric that has changed millions of cyclists and triathlete’s lives. I just wanted a “score”. Something that represented the training stress done each day by a cyclist. I called up Andy Coggan in 2002 and said, “Hey, we are getting these power files and have a complete second by second record of their training stress, we should be able to have a score for each ride. Do you think you can come up with something like that?” Two weeks later, Andy called me up and said, “Eureka, I’ve got it! It’s called Training Stress Score and it will take into account your FTP, the duration of your ride and the intensity of the ride as it relates to FTP. We’ll call it Training Stress Score. It’s loosely based on the TRIMPS score.” And that was that! TSS was born.

What TSS Actually Measures
TSS combines how hard you ride (intensity) with how long you ride (duration). A 100 TSS ride equals one hour at your threshold power. Ride longer or harder, and TSS climbs.

This allows us to compare a 2-hour Zone 2 ride with a 45-minute interval session. Both may leave you equally tired—but TSS quantifies the stress. Just because you scored 100 TSS in the 2hour Zone 2 ride, it doesn’t mean you improved your FTP! It’s just that you have accumulated the equivalent amount of training stress.

Why It Matters for Cyclists Over 40
As we age, recovery takes longer. TSS ensures you don’t dig yourself into a hole. By tracking cumulative load, you know whether you’re progressing or flirting with overtraining.

One of my 50-year-old athletes used to ride by feel. Some weeks he overloaded, others he undertrained. When we started tracking TSS, we balanced his weekly load. His fitness improved steadily, without the yo-yo effect of burnout and forced rest.

TSS and Training Plans
 Here’s a sample balanced week for a masters cyclist:

  • Tuesday: VO₂ Max Intervals (~90 TSS)
  • Thursday: Tempo Ride (~120 TSS)
  • Saturday: Long Endurance (~250 TSS)
    Total: ~460 TSS

For many riders over 40, this is sustainable and I would even up this a little to 500-600 TSS per week. Push that to 700-800 TSS week after week, and recovery cracks show.

Chronic vs. Acute Training Load
Software like TrainingPeaks uses TSS to calculate Chronic Training Load (CTL = long-term fitness) and Acute Training Load (ATL = short-term fatigue). The balance between them, called Training Stress Balance (TSB), predicts performance. A positive TSB often means you’re fresh and ready to peak.

Coaching in Practice
I had an athlete who plateaued despite training 12 hours per week. His weekly TSS was consistently too high, he was never fresh enough to adapt. By trimming hours but balancing TSS, he hit new FTP highs within months.

Conclusion
TSS changed cycling by turning raw data into actionable insight. It’s not about chasing big numbers, it’s about managing the right training load for your goals and your recovery capacity.

Want to learn how to manage training load like a pro? Try my free VO₂ Max Training Plan, it’s designed to balance stress and recovery.

The Ultimate Guide to Boosting Your VO₂ Max as a Cyclist Over 40

Posted on by Hunter Allen

You’re halfway up a steep climb, legs burning, breathing hard, but the summit feels farther away than it used to. As a cyclist over 40, you’ve noticed the shift – rides that once felt like a breeze now leave you winded sooner, and recovery takes longer. It’s not your imagination; it’s biology. But here’s the exciting truth: you can fight back and ride stronger than ever by focusing on one key metric: VO₂ Max.

VO₂ Max – your body’s ability to use oxygen during intense exercise – is the engine behind your endurance, power, and resilience on the bike. While it naturally declines with age, targeted training can slow or even reverse that slide, keeping you fast, strong, and competitive. At Peaks Coaching Group, under the guidance of renowned coach Hunter Allen, we’ve helped countless cyclists over 40 elevate their VO₂ Max with smart, data-driven strategies that prioritize performance without burnout.

In this guide, I’ll unpack what VO₂ Max is, why it’s your cycling superpower, and how to train smarter to boost it – tailored for the unique needs of cyclists over 40. Most importantly, I’ll show you how working with Peaks Coaching Group can unlock your best rides yet. Ready to climb faster and ride longer? Let’s dive in.

Why VO₂ Max Is Your Key to Staying Strong

Imagine your body as a high-performance engine. VO₂ Max is the engine’s capacity – how much oxygen it can process during a hard effort. A higher VO₂ Max means you can sustain intense efforts longer, whether you’re powering up a hill, sprinting in a group ride, or pushing through a century. It’s the difference between fading early and finishing strong.

As you age, VO₂ Max naturally dips – about 5-10% per decade after 30 – due to changes in lung capacity, muscle efficiency, and cardiovascular health. In your 40s, you might notice slower recoveries or earlier fatigue. By your 50s or 60s, sustained efforts can feel tougher. But here’s the game-changer: with the right training, you can maintain or even increase your VO₂ Max, defying age and riding with the vigor of your younger self.

The key isn’t grinding out more miles or pushing until you’re spent. It’s training smarter with precision, data, and recovery – exactly what Peaks Coaching Group specialize in. Our 4-step framework – Assess, Plan, Train, Recover – ensures every ride moves you closer to your peak. Here’s how to start boosting your VO₂ Max today.

Listen to Your Body’s Cues

Your body’s talking – are you paying attention? As a cyclist over 40, you can’t ignore signals like persistent fatigue, sluggish legs, or trouble sleeping, which might mean you’re overtraining. Conversely, feeling overly rested could signal you’re not pushing hard enough. Balancing intensity and recovery is critical as recovery times lengthen with age.

Start by tracking how you feel. For a week, jot down your energy levels, leg freshness, and sleep quality after rides. If you’re consistently drained midweek, add an extra rest day. If you’re raring to go, it’s time to dial up intensity with purpose. Prioritize 7-8 hours of sleep and hydrate with electrolytes to support recovery – non-negotiables for masters cyclists.

Try This Today:
After your next ride, note your energy and mood. If you’re wiped out, schedule a light spin or rest day this week to recharge.

Power Up With Targeted Intervals

VO₂ Max loves intensity, but random hard efforts won’t cut it. High-intensity interval training (HIIT) is your most effective tool for boosting aerobic capacity. These short, focused bursts push your heart and lungs to process oxygen better, building your engine without overtaxing your body.

Here’s a simple plan: After a 15-minute warm-up, do 4 x 3-minute intervals at 115% of your FTP – think super hard and barely controlled, where talking feels nearly impossible. Follow each with 3 minutes of easy pedaling to recover. Cool down for 10 minutes. A power meter is ideal, targeting Zone 5 (VO₂ Max, 115% of your Functional Threshold Power, or FTP). No power meter? Aim for an 8-9 out of 10 on perceived exertion. Do this once weekly, and you’ll feel stronger in weeks.

Try This Today:
Schedule one VO₂ Max interval session: 4 x 3-minute hard efforts with 3-minute recoveries. Note how your breathing and power feel compared to usual.

Build a Rock-Solid Aerobic Base

Intervals spike your VO₂ Max, but long, steady rides lay the foundation. These 2-4 hour rides at 65-75% of your FTP (Zone 2, conversational pace) strengthen your cardiovascular system and improve oxygen efficiency. Think of them as the base of a pyramid – without them, your high-intensity work won’t hold up.

Plan one weekly Zone 2 ride at least 3 hours long, keeping it comfortable yet purposeful. Use a power meter or heart rate monitor to stay in Zone 2 (50-70% of max heart rate without power). This builds endurance without draining recovery. One cyclist I coached added a weekly 4-hour Zone 2 ride and boosted their FTP by 12% in two months, making long rides feel effortless.

Try This Today:
Plan a 3-4 hour Zone 2 ride this weekend at a conversational pace. Track your energy afterward to gauge its impact.

Fuel for Performance

Your body’s less forgiving about poor nutrition as you age, so fueling right is critical for VO₂ Max training. Before a ride, eat a carb-rich meal 2-3 hours out (like oatmeal with fruit and ground flax seeds). On rides over 90 minutes, sip an electrolyte drink and eat carbs (banana or UCAN energy gel) every 45 minutes to avoid bonking. Post-ride, eat a carb/protein mix – like a smoothie with carb/protein powder and berries – within 30 minutes to jumpstart recovery. Your goal is to have at least 2x Carbs to 1x protein and it can go up to a 4:1 ratio of carbs/protein.  This will optimize your recovery. 

A continuous glucose monitor (CGM) can fine-tune this, showing how your body handles fuel in real time. One cyclist we worked with used a CGM to optimize carb timing, avoiding energy crashes and cutting 7 minutes off their 50-mile ride.

Try This Today:
Plan your next ride’s nutrition: a carb-rich pre-ride meal, an electrolyte drink, and a post-ride protein snack. Note how your energy holds up.

Track Your Gains

Improvement requires measurement. A power meter tracks FTP over time – a rising FTP often signals VO₂ Max gains. Without one, monitor heart rate: sustaining harder efforts at a lower heart rate shows progress. Field tests, like a 20-minute FTP test every 6-8 weeks, can quantify gains. Even subjective wins – like climbing a familiar hill faster – matter.

Try This Today:
Compare your power for 20 minutes or similar effort on a familiar route to last month. Note improvements or areas to adjust.

Why Peaks Coaching Group Is Your Edge

VO₂ Max training is personal – what works for a 25-year-old sprinter won’t fit your life as a cyclist over 40. That’s where Hunter Allen, founder of Peaks Coaching Group, comes in. A pioneer in power-based training, Hunter has coached cyclists worldwide to peak performance with tailored, data-driven plans. Whether you’re chasing a personal best or just want to love every ride, Hunter’s expertise ensures you train smarter, not harder, balancing intensity with recovery to hit your goals without burnout.

Ride Stronger, Climb Higher

Your 40s, 50s, 60’s and beyond can be your strongest cycling years. You have to start now though!   By training smarter – using targeted intervals, building your aerobic base, fueling strategically, and tracking progress – you can boost your VO₂ Max and ride with power and confidence.

Ready to unlock your full potential? Book a free performance consultation with Hunter Allen at Peaks Coaching Group. He’ll craft a personalized, 30-day plan to skyrocket your VO₂ Max and transform your rides, tailored to your goals and lifestyle.

→ Book Your Free Performance Consultation with Hunter Allen

Your Best Climbs Are Ahead

You don’t have to let age steal your speed or stamina. Try one micro-action today – like planning an interval session or optimizing your fuel – and see how it feels on your next ride. When you’re ready to take your VO₂ Max to new heights, Hunter Allen and Peaks Coaching Group are here to guide you to stronger, faster, more exhilarating rides than ever.To your strongest climbs,
Peaks Coaching Group