Online dumbbell workout counter and log for left and right arm on Intellect

The online dumbbell workout counter and log is a free tool for people who train at home or in the gym and want to know exactly how many sets and reps they have done with the left and the right arm. It is easy to lose count during a workout: you finish a biceps set with your right arm, rest, check your phone — and no longer remember which arm is next or how much work the left arm has done. This tool solves the problem: a large label and an animation show which arm is working right now, and detailed statistics for each arm are kept below.
What a left and right arm set counter is for:
- not getting confused about which arm does the next set when you alternate with one dumbbell;
- keeping the load on both arms equal and avoiding strength and muscle imbalances;
- seeing the total number of sets and reps in the workout;
- controlling rest between sets with a timer;
- tracking progress in different exercises: biceps curl, hammer curl, overhead press, lateral raise, bent-over row, overhead triceps extension or your own exercise.
How to use it:
1. Choose the exercise, the arm order (alternate left and right, left only, right only or both arms at once), the goal as “sets × reps” (4×40 by default) and rest time.
2. Look at the large “LEFT ARM” or “RIGHT ARM” label and the animation: the highlighted arm with the dumbbell is the one that should work.
3. Press the big “START” button and do the set. While the set is in progress, the animation shows the movement and a stopwatch measures time under load.
4. When you finish, press “DONE”. A field appears where you enter how many reps you did. Your target is filled in by default; change it with the “−” and “+” buttons or pick a quick value.
5. Save the set. The tool automatically switches to the other arm and starts the rest timer. When the rest is over, a sound plays and the phone vibrates.
What the statistics show:
- the number of sets and reps separately for the left and right arm;
- the best set for each arm;
- the total number of sets, reps and time under load;
- the difference between arms: the tool tells you which arm is behind and by how many reps;
- a summary by exercise and a detailed history of all sets with time.
Why it matters to count reps for each arm separately:
Dumbbell exercises are unilateral training, where each arm works on its own. This helps balance the strength of the right and left side, since for most people the dominant arm is stronger. But this effect only appears if both arms get the same volume of work. When counting in your head, it is easy to do an extra set with the strong arm or skip reps with the weak one. The visual counter and the L/R balance bar show it immediately. A good practice is to start a set with the weaker arm and do as many reps with the stronger arm as the weaker one managed.
Workout goal and praise:
Set a goal, for example 4×40 — four sets of 40 reps with each arm. The tool compares it with the “Result, each arm” line: as soon as the average number of sets and reps reaches the goal, you hear one of the congratulation phrases and “Goal reached!”, the final window with the summary opens and the workout ends. You do not need to count how much is left — the tool tells you when you are done.
Voice control — your hands are busy with dumbbells:
Press the “🎤 By voice” button and allow microphone access. After every set the speech synthesizer asks: “How many reps with the left arm?” — just answer out loud “left 20” or simply “20”. The tool recognizes the answer, fills in the number, saves the set automatically, reads the result back and tells you which arm is next. You can dictate several sets in a row: “left 20, right 20” — each one is recorded separately. Voice commands also work: “start”, “done”, and “undo” to remove the last set. Small RU and EN buttons switch the voice language: questions and recognition work in Russian or English regardless of the page language. When the rest timer ends, the tool announces it by voice. Speech recognition works in browsers with the Web Speech API (Chrome, Edge, Safari); if it is unavailable, every feature is still available through the buttons.
Convenient during a workout:
- large font and color coding: left arm is blue, right arm is orange, both arms are purple;
- big “START” and “DONE” buttons that are easy to hit even with gloves on;
- fullscreen mode so you can put your phone or tablet on the floor or a stand;
- the screen stays on during a set in browsers that support Screen Wake Lock;
- keyboard shortcuts on a computer: Space — start/done, Enter — save, L and R — choose arm;
- an undo button for the last set if you pressed something by mistake.
All data is stored only in your browser: no registration, nothing is sent anywhere. You can close the page and come back later — the workout statistics are kept until you press “New workout”.
The tool suits beginners and experienced athletes, home dumbbell workouts, gym sessions, rehabilitation exercises recommended by a specialist and single-dumbbell training where the arms work in turns.