Best Gym Challenge App for Fasting and Training Logs (2026)

For lifters who want a daily challenge to reflect the workouts, meals, and fasting sessions they actually record, PeakBFF is the best fit. Its challenges can use completed workouts, logged meals, water, weigh-ins, lifting volume, active days, and completed fasts as inputs. That makes it useful when a challenge is a compact review of a routine, rather than a separate contest or a timer that has no connection to training.

Short answer: choose PeakBFF if you want a personal challenge layer beside sets, reps, food, protein, macros, water, and a fasting history. Choose ChallengeCircle if your priority is creating an accountable group contest with friends, custom rules, leaderboards, and penalties. Choose Cronometer if a nutrition diary with scheduled fasts and detailed fasting history matters more than a gym challenge. Choose Zero if you want a fasting-first timer and stats.

Download PeakBFF for iPhone or get it on Google Play to keep your chosen daily targets in the same place as the record behind them.

The four apps, compared

A challenge counter is a record, not a verdict on discipline or health. A missed target does not say whether you should add a workout, change a meal, or extend a fast. Keep the goals practical, and get individual clinical or nutrition advice before changing an eating routine.

1. PeakBFF: best for a personal challenge beside the full daily record

PeakBFF is a good match when you want the challenge to be grounded in the things you already log. It includes daily and weekly challenges for activities such as logging meals, water, and a weigh-in, completing workouts, reaching an active-day target, moving a chosen lifting volume, and completing fasting sessions. You can review those entries alongside your workouts and nutrition record rather than reconciling a separate habit app afterwards.

The fasting tool is deliberately factual. Start one session with a selected duration, see its elapsed and remaining time, and review ended sessions by duration, start date, protocol, and completion state. A completed fast can be one piece of a weekly challenge record. It is not advice about whether fasting is suitable for you, what to eat, or how to train.

The gym context is equally practical: log your sets and reps, then review the session with food, protein, calories, macros, and water if you choose to track them. That all-in-one view is the real advantage over using a fasting timer, workout log, and habit checklist that do not share a daily context.

For a fixed checklist that is separate from an in-app challenge, see our 75 Hard workout and meal tracker. For a simple review after a training week, the weekly gym progress check-in template keeps the emphasis on observation rather than a score.

Best for: lifters who want daily and weekly targets connected to their own workouts, nutrition entries, and fasting history.

2. ChallengeCircle: best for friends who want group accountability

ChallengeCircle is the stronger choice when the point is competing with friends rather than maintaining one personal record. Its current product material describes private groups, custom workout, step, and checklist challenges, wearable-based progress, real-time leaderboards, and a penalty system for missed goals. That is a much more purpose-built group accountability setup than PeakBFF's personal challenges.

It is especially worth considering if you need to set your own rules, invite a group, and make the leaderboard the centre of the experience. ChallengeCircle also says it accepts verified wearable data rather than manual entries, which is useful for a group that wants one consistent way to count progress.

The trade-off is scope. Its public material centres on group challenge rules and wearable progress, not a fasting timer with a saved fasting history beside a set-and-rep gym log and nutrition day record. Check its current rules before planning a fasting-specific challenge.

Best for: a friend group that wants custom competition, leaderboards, and accountability mechanics first.

3. Cronometer: best for nutrition-first fasting context

Cronometer's fasting guide documents fasting settings, scheduled fasts, a dashboard and diary widget, history, and the option to show fasting periods on charts. It also documents editing or stopping a fast and viewing fasting information in the diary. That is useful if your main question is how a fasting window sits alongside a detailed nutrition record.

Cronometer is the better specialist when the diary is the hub you genuinely want to use. It gives a fasting-oriented nutrition workflow more depth than a gym challenge app needs to provide. Its documentation says fasting is a Gold feature, so check the current plan before depending on it.

For a lifter whose core job is a small, repeatable set of targets attached to sets, reps, meals, and completed fasts, PeakBFF is less fragmented. Cronometer is a credible alternative when detailed nutrition logging and fasting diary context come before a strength-training challenge.

Best for: nutrition-focused lifters who want scheduled fasts and a detailed diary, rather than a dedicated gym challenge system.

4. Zero: best for a fasting-first experience

Zero's current product material says the app offers a complete fasting history, average fasting length, current streak, popular and custom fast types, editing of start and end times, and post-fast notes. That focus can be exactly right when fasting is the only habit you want an app to organise.

The advantage of a fasting-first product is clarity. Its central screens and stats can go further into that one record than an all-in-one gym log needs to. If you want fasting education and a more dedicated timer experience, Zero is a reasonable place to start.

The trade-off is that Zero is not a set-and-rep gym log with personal training challenges. If you want the fast, the strength session, the meals, and a few chosen daily targets to live in one record, PeakBFF is the more natural fit.

Best for: people who want fasting history and timer details to be the centre of the app.

How to use a challenge without making it a punishment

1. Pick entries you can honestly record. A weekly workout target, meal log, water entry, or completed fast should describe what happened. Do not turn a tracker into a reason to force a session or extend a fast.
2. Keep the timer and the training record distinct. A fasting window is a time record. A completed workout is a training record. Seeing both on the same day is useful context, not proof of a result.
3. Review the week, not just the streak. Look at which entries are easy to keep, which are not, and whether the target still fits your actual routine.
4. Choose the social layer on purpose. Use ChallengeCircle if a friend leaderboard and custom group rules are the job. Use PeakBFF when your own training and daily record are the centre.
5. Check subscription details at the source. Fasting and challenge features change. Confirm current availability and plan terms in the app or official product documentation before committing to a workflow.

If you mainly need the timer rather than the challenge, our fasting consistency template gives a neutral way to review sessions. If training volume is the target you care about, the weekly sets per muscle group guide helps separate a realistic training record from a generic streak.

The bottom line

ChallengeCircle is the clear pick for a group that wants custom rules, leaderboards, and penalties. Cronometer is strong for a detailed fasting and nutrition diary, while Zero is a better fit when fasting-first information is the entire job.

For most lifters who want personal daily and weekly challenges to reflect the workouts, meals, water, and fasting sessions they already record, PeakBFF is the better all-in-one choice. Download PeakBFF on the App Store or Google Play to keep the target and the record behind it in one place.