Comparison

Cardio Conversion vs Peak Intervals

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Cardio Conversion

Features
Read full description

Cardio Conversion instantly converts workout distances between gym equipment. When your workout calls for 400m run but you only have a rower, CardioConversion tells you exactly how many meters to row for equivalent effort. FEATURES • Convert between running, rowing, skiing, biking, and more • See calories burned for male and female athletes • Quick presets for common distances (400m, 800m, 1600m, 5000m) • Dark mode support • Works offline - no internet required PREMIUM FEATURES • Unlock additional equipment: burpees, pull-ups, wall balls, and more • Customize conversion ratios to match your fitness level • Reorder equipment tiles to match your preferences • Ad-free experience Perfect for CrossFit, functional fitness, and HYROX training. EQUIPMENT SUPPORTED Free: Outdoor Run, Row Erg, Echo Bike, Assault Bike Premium: AirRunner, Ski Erg, Bike Erg, Burpees, Pull-ups, Wall Balls, Double Unders, Box Jumps, Air Squats, Kettlebell Swings

About

Peak Intervals

Features
Read full description

Peak Intervals guides two endurance workouts with Apple Watch or a Bluetooth heart rate monitor: the Norwegian 4x4 to train your VO₂ max, and steady Zone 2 sessions to build your aerobic base. It shows how each session went. Guided workouts need Apple Watch or a Bluetooth heart rate monitor, and a Peak Intervals Pro subscription, with a 2-week free trial where available. History, Trends and the analysis of your Apple Health workouts are free. NORWEGIAN 4x4 • Four 4-minute intervals at 90–95% of your max heart rate, with 3-minute recoveries. • Live guidance keeps you in the zone: haptic cues on Apple Watch, and voice cues with headphones. • Afterwards, see whether you reached the zone quickly, stayed in it during every interval, held your pace or power from the first interval to the last, and how fast your heart rate came down in each recovery. ZONE 2 • Run, ride, row or walk on an incline, indoors or outdoors, with a guided warm-up and cool-down. • An alert tells you when you drift out of the zone, and a talk test at 15 minutes asks how the effort feels. • Afterwards, see how much of the session you spent in the zone, whether your heart rate crept up at the same effort (decoupling), and how your power or pace at Zone 2 heart rate compares with your last session of the same activity. ZONES THAT FIT YOU • Your max heart rate starts from an age estimate and goes up if a recent workout in Apple Health reached a higher heart rate. • Zone 2 uses your Apple Health heart rate zones on iOS 27, or your resting and max heart rate. • Your talk test answers help tune the zone: after three easy sessions the app offers to raise it, and when talking gets hard it offers to lower it. You decide. TRENDS AND HISTORY • Compare your last 3 sessions with the 3 before, with a clear verdict such as Improving or Stable. • See your VO₂ max and resting heart rate from Apple Health next to your training. • Every session in one place, including workouts from Apple Health. • Share a session as a story or post, with your own photo in the background. APPLE WATCH OR A HEART RATE MONITOR • With Apple Watch, the workout runs on your wrist with haptic cues, and your iPhone follows live, also on the Lock Screen and in the Dynamic Island. • With a Bluetooth heart rate monitor paired in iOS Settings, the workout records on your iPhone: live zones on screen, voice cues in your headphones, the Lock Screen and the Dynamic Island. Haptics are Apple Watch only. Apple Health Peak Intervals reads workout and heart rate data from Apple Health (HealthKit) to calculate your metrics and trends. You control what is shared at any time in iOS Settings. Subscriptions Peak Intervals offers an auto-renewing subscription with monthly and yearly plans, including a 2-week free trial where available. After the trial, an active subscription is required to start new workouts. Payment is charged to your Apple ID account at confirmation of purchase. Subscriptions renew automatically unless canceled at least 24 hours before the end of the current period. You can manage or cancel your subscription in App Store account settings. Peak Intervals is not a medical device and does not provide medical advice. High-intensity exercise may not be appropriate for everyone. Consult a physician before beginning a new training program. Privacy Policy: https://peakintervals.app/privacy Terms of Use: https://peakintervals.app/terms

Screenshots

Cardio Conversion4 screens
Peak Intervals4 screens

Verdict

The call

The clearest difference is iOS requirement: Cardio Conversion at 15.1 against Peak Intervals's 26.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Cardio Conversion sells 1 one-off in-app purchase and Peak Intervals sells 2 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Cardio Conversion ships an update weekly, Peak Intervals every 4 days. The most recent releases landed on November 4, 2026 and October 31, 2026 respectively.

Scorecard1 real difference · 5 level
Cardio Conversion versus Peak Intervals: the parameters behind the verdict, then further details
ParameterCardio ConversionPeak Intervals
PriceFreeFree
Update frequencyWeeklyEvery 4 days — better
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPad, iPod — betteriPhone, Apple Watch
Requires iOS15.1 — better26.0
Further details — not scored
Size33 MB19 MB
Age rating4+17+
DeveloperRyan RodemoyerJustin Polidori

In-app purchases

1 purchases

Cardio Conversion

One-time1
  • Premium Unlock$4.99
2 purchases

Peak Intervals

Subscriptions2
  • Pro Monthly3 Days trial$9.991 Month
  • Pro Yearly14 Days trial$49.991 Year

Questions

Is Cardio Conversion free?
Cardio Conversion is free to download, with in-app purchases available.
Is Peak Intervals free?
Peak Intervals is free to download, with in-app purchases available.
Do Cardio Conversion or Peak Intervals have ads?
Neither Cardio Conversion nor Peak Intervals shows ads.
Which is updated more often, Cardio Conversion or Peak Intervals?
Cardio Conversion ships an update weekly, and Peak Intervals every 4 days. Most recently, Cardio Conversion was updated on November 4, 2026 and Peak Intervals on October 31, 2026.

Other comparisons