INSCYD vs TrainingPeaks vs Coachbox: Testing, Training, or Both?

TL;DR: INSCYD builds a metabolic profile of your athlete, with VO2max, VLamax, fat and carbohydrate combustion (fuel utilization) and predictive modeling through its performance projection (INSCYD metrics). In our view, no other tool in this comparison goes that deep. In our experience, TrainingPeaks is where a large share of endurance coaches handle training plan delivery, with TSS, CTL and ATL, a training plan marketplace and a coach directory (TrainingPeaks for coaches). Asked whether it is “a training platform like TrainingPeaks”, INSCYD answers that it “is not a training platform where a coach creates training programs” (INSCYD FAQ), so many coaches run the two side by side as complementary tools. Coachbox puts lactate testing with automatic threshold detection and a coaching platform for training planning, athlete communication and daily workflow in one tool. It does not build a metabolic model the way INSCYD does.

Update, 22 July 2026: Garmin has acquired TrainingPeaks and TrainHeroic from Peaksware Holdings (Garmin press release). The announcement did not mention changes to device support, pricing or coach accounts, so everything below describes the platform as we found it on its own website. For what the deal does and does not change, read Garmin acquires TrainingPeaks.

The Case for INSCYD

INSCYD deserves its reputation in the metabolic testing world. Let’s give it the credit it has earned.

Metabolic Modeling and Performance Projection

INSCYD does more than find a lactate threshold. It calculates VO2max, VLamax (glycolytic power), the anaerobic threshold at MLSS, LT1, fat and carbohydrate combustion, economy, recovery and energetic contribution (INSCYD metrics), as well as FatMax (Power Performance Decoder).

Because the metrics come from one model, you can ask what a change in one of them does to the rest. With Performance Projection, INSCYD lets you “predict the effects of a change in any performance metric on the overall performance of your athlete” (Performance Projection). In our reading, that covers a question like what happens to threshold power if VLamax drops through base training. In the other two products in this comparison, we did not find anything like it.

Scientific Grounding

Sebastian Weber, a sport scientist, founded INSCYD (INSCYD), and INSCYD says he has used his knowledge to help world tour cyclists win “9 world championship titles, Olympic medals and Tour de France victories” (INSCYD camp). INSCYD says its software is “not based on something we came up with through statistical analysis” but on physiological mechanisms “derived from more than 150 peer reviewed scientific papers and studies” (What is INSCYD). For practitioners whose methods need to hold up in universities, national federations or elite teams, that matters.

The client list on INSCYD’s homepage includes Movistar Team, Team Alpecin Fenix, CANYON//SRAM, the Belgian Cycling Federation, the German Swimming, Skiing and Triathlon Federations, and INSEP in France (INSCYD).

Protocol Flexibility

INSCYD works with lab tests, field tests and remote tests (INSCYD, lactate testing). Its Power Performance Decoder (PPD) is a remote test: athletes complete prescribed efforts wherever they are, with a power meter on the bike or a GPS watch for running, and the data feeds the metabolic profile (Power Performance Decoder). For coaches with athletes spread across the world, that is a practical advantage.

Fuel Utilization: Where Physiology Meets Nutrition

INSCYD models fat and carbohydrate combustion, including the intensity at which an athlete burns more carbohydrate than they can take in, which it calls CarbMax. INSCYD positions this for building fueling plans for training and racing (What is INSCYD). In ultra-endurance events, where nutrition often decides the day, we find this one of its most useful outputs.

The Case for TrainingPeaks

In our view, TrainingPeaks solves a real problem, and a lot of coaches rely on it.

Training Plan Delivery

The coach platform covers calendar planning, structured workouts, recurring workouts, compliance colors, the Performance Management Chart and a workout library (TrainingPeaks for coaches). The PMC with CTL (fitness), ATL (fatigue) and TSB (form) is built on TSS, which TrainingPeaks documents in detail (the science of the Performance Manager).

In our view, TSS, CTL and ATL have become a shared language in endurance coaching. When coach and athlete both understand them, they have a common framework for training load, recovery and peaking.

A Coach-Athlete Marketplace

TrainingPeaks connects coaches with athletes. It reports more than 100,000 marketplace visits per month and more than 70,000 training plans sold in 2023 (TrainingPeaks for coaches). Athletes can browse a coach directory (TrainingPeaks coach search) or use Coach Match, which pairs them with an accredited coach (Coach Match). For a coach building a practice, that exposure has real value.

Workout Builder, Library and Annual Plan

Structured workouts with target zones and a workout library let you build and reuse sessions (TrainingPeaks for coaches). For season planning, the Annual Training Plan (ATP) periodizes training automatically toward an “A” priority event, based on average weekly hours, weekly TSS or a target fitness (CTL) (ATP setup).

Third-Party Ecosystem

TrainingPeaks says it “syncs with more brands than any other endurance training app”, naming Garmin, Suunto, Zwift, Wahoo, Apple Watch and Polar (coach features). In our view, that reach is a big part of why coaches and athletes stay on the platform.

Athlete Communication

Athletes see their plan in the calendar, and coaches follow compliance and leave post-activity comments (TrainingPeaks for coaches). TrainingPeaks Messaging adds direct and group conversations between coaches and Premium athletes, in the web and mobile apps; the help page lists attachments such as photos, videos and documents as coming next (TrainingPeaks Messaging).

Where the Two Leave a Gap

INSCYD is open about the split. Its FAQ says INSCYD “is not a training platform where a coach creates training programs or communicates to the athlete what the athlete should do”, but “the platform where the coach discovers what the athlete should focus on in training” (INSCYD FAQ). Its own article on the topic describes a workflow where coaches test in INSCYD and then roll out the program in a platform like TrainingPeaks (TrainingPeaks vs INSCYD). The distinction is fair. It also means you work in two tools.

Two Tools, Two Workflows

If you follow that setup, you use INSCYD for metabolic analysis and TrainingPeaks for training delivery: two subscriptions and two logins. On INSCYD’s integrations page we did not find a TrainingPeaks connection; it lists AZUM, which receives INSCYD benchmarks and zones over an API, plus Stryd, Velocity and CARDIOWORLD (INSCYD integrations, INSCYD and AZUM).

In our view, a typical cycle then looks like this:

1. Run the test and collect the data
2. Analyze it in INSCYD
3. Interpret the metabolic profile
4. Take the zones and recommendations out of INSCYD
5. Log into TrainingPeaks
6. Update the athlete’s zones
7. Revise the training plan
8. Share the results with the athlete, for example with INSCYD’s PDF report (INSCYD reports)

That is eight steps across two platforms, with a manual handover in the middle. For a coach who tests many athletes every quarter, we think that handover adds up.

We Did Not Find Lactate Analysis in TrainingPeaks

TrainingPeaks is built around training delivery. It can detect new heart rate, power and pace thresholds from workouts, such as a peak 20, 45 or 60 minute effort, and suggest or apply them (threshold notifications). Its own coach guide to lactate testing points to Thresholds Over Time for tracking the values you found (a coach’s guide to lactate testing). We did not find a way in TrainingPeaks’ documentation to record blood lactate measurements from a step test and derive thresholds from them.

TrainingPeaks coaches who want to add lactate testing therefore tend to use one of these:

• INSCYD, which sells to coaches, labs, federations and universities, starting with a demo (INSCYD FAQ)
• WinLactat, which mesics describes as “PC software for Windows” (mesics software); mesics also offers the free Lactate Express App for iOS and macOS, which analyses measurements from its own meters (Lactate Express App)
• Another lactate analysis tool
• A custom spreadsheet

In our experience, the result then reaches TrainingPeaks as zones you enter by hand.

INSCYD Is Not a Training Platform

INSCYD produces metabolic profiles, training zones and reports, and it helps you design individual interval sessions from the profile (What is INSCYD, training zones). But in its own words, “INSCYD doesn’t create training programs” (INSCYD FAQ). We did not find a training calendar, athlete messaging or compliance tracking among its functions (INSCYD functions). The daily work of coaching happens elsewhere.

The Cost of Two Platforms

Running INSCYD plus TrainingPeaks means:

• An INSCYD plan without a published price; INSCYD says “your fees scale with the quantity of analysis you perform”, based on the number of tests or athletes (INSCYD FAQ)
• A TrainingPeaks coach subscription, from 21.99 USD/month billed monthly, excl. taxes, plus Premium athlete accounts if you want them (TrainingPeaks for coaches)
• Time spent moving results between two platforms
• Two support channels when something goes wrong

For independent coaches, in our view, those combined costs weigh on already thin margins.

The Case for Coachbox

Coachbox sits in the gap between tools like INSCYD and platforms like TrainingPeaks. It combines lactate testing with a coaching platform, so the analysis and the coaching happen in the same place.

Testing and Coaching in One Platform

When you run a lactate test in Coachbox:

1. Enter lactate values from any meter, in any browser, or take a photo of a paper protocol
2. Coachbox detects LT1 and LT2 automatically in under a minute
3. Zones are calculated and updated in the athlete’s profile
4. Future workouts use the new zones
5. A branded PDF report is ready to share
6. The athlete sees the results in the same app they check their schedule in

No second platform and no manual zone transfer.

Automatic Lactate Analysis

Coachbox detects thresholds automatically across several methods, and you override the result when your coaching judgment disagrees.

This trades INSCYD’s metabolic depth for speed. Coachbox does not build a full metabolic model. It analyzes the lactate curve, identifies thresholds, calculates zones and generates reports. In our view, that covers what most coaching situations need.

The Full Coaching Platform

Beyond testing, Coachbox includes:

• Training calendar with workout scheduling and periodization
• Athlete profiles with the full training and testing history
• Zone management that updates from test results
• Workout prescription with zone-aware intensity targets
• Athlete communication through in-app messaging and comments on workouts
• Annual periodization tools for season planning
• Analytics dashboard with PMC, load trends and progression tracking
• Branded PDF reports
• Health monitoring with HRV, sleep and resting heart rate synced from devices
• Coachbox AI, which answers questions about an athlete and can write changes into their training plan, plus an MCP connection to ChatGPT and Claude

Planning, a PMC, workout comments and an annual plan are common ground with TrainingPeaks (TrainingPeaks for coaches). Lactate testing is where Coachbox overlaps with INSCYD (lactate testing), at a different depth.

Published Pricing

Coachbox publishes its prices. All amounts are excl. VAT.

An athlete counts as active when they have workouts planned in the future. Every plan includes free lactate tests at the start of your license, 5 to 20 depending on the plan; after that a test costs 3 to 6 EUR excl. VAT depending on the plan.

For labs and occasional testers, there is a standalone Lactate Module at 49 EUR/month billed yearly, excl. VAT, with test packs of 50, 100 or 250 tests for 250, 400 or 750 EUR.

Start Without a Sales Call

You sign up, start a free trial and run your first test the same day. INSCYD starts with a demo (INSCYD) and onboarding that includes two hours of one-to-one consultancy (INSCYD FAQ), which suits labs and teams that want that guidance.

25,000+ Users, 12M+ Workouts

More than 25,000 coaches and athletes use Coachbox, and they have logged more than 12 million workouts.

Three-Way Comparison Table

All prices in the table are what a coach pays, without VAT or sales tax. TrainingPeaks lists its coach prices in USD and notes that “additional taxes may apply” (TrainingPeaks for coaches); Coachbox lists its prices in EUR without VAT. We do not convert between the two currencies.

What TrainingPeaks Charges a Coach

TrainingPeaks bills per coach account and per Premium athlete, so the total depends on your roster and on how many of your athletes want Premium (TrainingPeaks for coaches):

• Coach Edition: 21.99 USD/month billed monthly with 4 Basic athlete accounts and 1 Premium athlete account, or 54.99 USD/month with 5 or more Basic athlete accounts. A 99 USD start-up fee applies, which TrainingPeaks waives with a coupon code on the page (source).
• Premium athletes: 9 USD per athlete per month when the coach pays, with volume discounts from 5% (10 to 19 athletes) up to 50% (1,000 or more). Athletes can also buy Premium themselves (source).

All TrainingPeaks amounts are in USD, excl. taxes (TrainingPeaks for coaches). Coachbox charges a plan with a number of athletes included and a fee per extra active athlete, and athletes on a coach’s plan pay nothing. Because the two models bill different things, we do not add them up into one yearly total.

The Real Comparison: Workflow, Not Features

Feature tables are useful, but they don’t capture the daily reality of using these tools. Here’s what each setup looks like in practice, in our view.

The INSCYD + TrainingPeaks Coach

You run metabolic profiles in INSCYD (quarterly or as needed), carry the zones over to TrainingPeaks (TrainingPeaks vs INSCYD), deliver training through the TrainingPeaks calendar, and talk to athletes through TrainingPeaks and other channels.

Strengths: The deepest metabolic insight in this comparison, combined with a widely used training delivery platform. Strong in professional and elite settings.

Friction: Two platforms and a manual handover of zones, plus separate reporting. The admin grows with the number of athletes.

Best for: Performance physiologists at pro teams who have dedicated time for testing analysis and whose athletes already use TrainingPeaks.

The TrainingPeaks-Only Coach

You deliver training through TrainingPeaks, use TSS-based metrics for load management, and either skip physiological testing or combine a separate lactate tool or spreadsheet with it.

Strengths: A large ecosystem where athletes and coaches speak the same language (TSS, CTL, FTP), a marketplace and a coach directory.

Friction: Lactate testing and metabolic profiling happen outside the platform. Zones come from threshold detection in workouts, field tests or manual input from external tests.

Best for: Coaches who work fully inside the TrainingPeaks ecosystem and don’t offer lactate testing as part of their service.

The Coachbox Coach

You run lactate tests in Coachbox, zones update, future workouts use them, and athletes see results in the same app. One platform for testing and coaching.

Strengths: No handover between testing and training. Each test feeds the zones of the workouts that follow. Branded reports without extra tools.

Friction: No marketplace yet (one is planned), and a smaller ecosystem than TrainingPeaks (coach features). No metabolic modeling at INSCYD’s depth. Athletes who are invested in TrainingPeaks need to switch apps.

Best for: Coaches who want testing and coaching in one place and who run lactate tests as a regular part of their coaching.

Who Should Choose What

Choose INSCYD if you are…

• A performance physiologist whose main job is metabolic profiling
• Working with professional teams or elite athletes where VO2max, VLamax and fuel data justify the cost
• Interested in performance projection and fueling plans built on combustion rates
• Testing athletes remotely, with the Power Performance Decoder
• Already using TrainingPeaks and happy to keep it for coaching
• Offering metabolic testing as a standalone service; INSCYD puts the usual price athletes pay for one profile at 200 to 450 USD (INSCYD FAQ)

Your stack: INSCYD (testing) + TrainingPeaks or another platform (coaching). Two subscriptions, with a manual handover.

Choose TrainingPeaks if you are…

• A coach who doesn’t offer physiological testing and focuses on training delivery
• Invested in the TSS/CTL/ATL framework for load management
• Relying on the marketplace, coach directory or Coach Match for new clients
• Happy with zones from FTP, threshold pace or heart rate detected in workouts
• Working with athletes who are already on TrainingPeaks

Your stack: TrainingPeaks only. Add INSCYD or another tool if you later want to offer testing.

Choose Coachbox if you are…

• A coach who wants testing and coaching in one platform
• Running regular lactate tests as part of your coaching
• Managing multiple athletes and looking for less admin per athlete
• Wanting one subscription that covers testing, training, communication and analytics
• Looking for published pricing and a free trial without a sales call
• Building a coaching brand with branded reports

Your stack: Coachbox only.

Can You Combine Them?

Yes. Some practical combinations:

INSCYD + Coachbox: Use INSCYD for deep metabolic profiling once or twice a year. Use Coachbox for regular lactate testing and daily coaching. The INSCYD insights inform your training direction, and Coachbox handles execution.

TrainingPeaks + Coachbox: Use Coachbox for lactate testing and analysis, then enter the zones in TrainingPeaks if that’s where your athletes already are. Not the shortest workflow, but practical during a transition.

In our experience, a common path is this: coaches start with TrainingPeaks, add INSCYD or another testing tool, get tired of the manual handover, and move testing and coaching into one place.

The Bigger Picture

In our view, INSCYD and TrainingPeaks are both good at what they set out to do. INSCYD pushed the industry toward deeper metabolic understanding. TrainingPeaks made TSS, CTL and ATL part of how coaches talk about load. Both deserve credit.

INSCYD’s own answer to whether it is “a training platform like TrainingPeaks” (INSCYD FAQ) also shows the gap: if you want metabolic profiling from INSCYD and training delivery from TrainingPeaks, you work in two tools, and you move the results between them yourself.

Coachbox was built to close that gap for lactate testing. It doesn’t match INSCYD’s metabolic depth, and it has no marketplace yet like TrainingPeaks’ (TrainingPeaks for coaches). What it does is put testing and coaching in the same place, so a lactate test feeds the zones of every workout that follows.

For many working coaches, we think that connection matters more than any single line on a spec sheet. The coaching tool that helps most is the one you open every day, and you test more often when the analysis takes minutes.

Choose the setup that matches how you coach, not the one with the longest feature list.