Indie App Spotlight: Athlete Space is a free AI coach that replans your week

Every training plan looks good on the day it’s written. Then a child brings a cold home from nursery, a work trip lands on a long-run weekend, and the plan falls apart. Most apps carry on as if nothing happened, and the athlete is left rebuilding the week by hand.

Athlete Space is a free AI coach for runners, cyclists, swimmers, triathletes and HYROX athletes, built to handle what happens next. It follows workouts, weighs recovery, adjusts upcoming sessions around changing schedules and explains each decision. Athletes can ask it questions, challenge its recommendations and tell it what is going on in their lives, and it can also guide them through a session with cues in their headphones.

A coach that follows the training

Setup takes a few minutes. The athlete says what they want to achieve, how much time they have and which days they can train, whether the goal is a first 5K, a Boston qualifier, a faster Ironman, a HYROX race or simply getting fitter. The coach builds a programme around that, and training starts straight away rather than the following Monday.

TL;DR: Athlete Space runs three coaching cycles every day.

• After training, it compares what the athlete actually did with what was planned.
• Overnight, it reviews the training week and adjusts upcoming sessions.
• Every morning, it weighs sleep and recovery data, where connected, before setting the day’s workout.

An easy run that turned into a hard effort counts as a hard effort, a disrupted night can soften the next morning’s session, and a family holiday can be planned around before it arrives. The coach starts learning individual recovery patterns after about a week of overnight data, compared against a rolling 28-day baseline.

How the coach makes decisions

Athlete Space draws on four sources of information:

• Training progress: completed workouts, distance, pace, power and intensity, and how they compare with the programme.
• Recovery: sleep, heart rate variability and resting heart rate, against the athlete’s own baseline.
• Everyday life: work, travel, family, illness and other changes the athlete reports.
• Conditions: weather forecasts, heat and humidity, hills and race-course terrain.

If an athlete has trained harder than planned, the next session accounts for it. If recovery is poor, the day’s workout gets easier, and if a trip is coming up, the week is reorganised before it starts. Hills feed into pacing and effort targets, and heat and humidity are weighed against the athlete’s acclimatisation.

A missed session is not automatically squeezed into the next day. Sometimes the coach moves it, sometimes it swaps in something easier, and sometimes it lets the session go. Every change comes with an explanation, and the athlete can push back: asking to keep Saturday’s long run where it is, for example, makes the coach rebuild the sessions around it.

During a workout or race, Athlete Space can talk to the athlete through their headphones, from simple reminders to detailed pacing and effort instructions. It also offers Norwegian-style running and cycling plans built on double-threshold training, aimed at athletes with about six hours a week and at least two years of consistent training behind them.

One marathon, plenty of real life

Bruno Artacho, who built Athlete Space, uses it as his own coach. His build for the St. Jude Memphis Marathon in December 2025 shows how it handles a block that doesn’t go to plan. He had a full-time job, a toddler at home and a hot, hilly Nashville summer to train through, and his weekly mileage started at 40 and peaked at 81.

• Mid-October, 75 miles became 51. A bug from nursery went through the family and a 10-mile race went badly. The coach eased the following days rather than trying to make up the lost miles.
• Late October, 81 miles. The peak week finished with a 20-mile run at 6:30 per mile (4:02 per km).
• Early November, 37 miles. Five weeks out, a family trip to South Carolina coincided with a flare-up of a long-standing IT band problem. Artacho gave the coach the travel dates and details of the injury, and it let four days of training go rather than cramming them into the next week.
• Mid-November, 80 miles. Training returned to its previous level, finishing with a 15-mile run at 6:29 per mile.
• After Thanksgiving, 55 miles. His daughter was ill again and he spent a night on the floor beside her. He told the coach, which checked his HRV against his baseline and softened the next day’s session before he ran.
• 6 December 2025. Artacho finished the Memphis Marathon in 2:29, third overall and one minute behind the winner.

One result doesn’t prove that AI coaching beats a human coach. It does show a coach that kept adjusting through a messy block while the athlete got on with training and family life.

Quick answers

Is Athlete Space really free?
Yes. The training plan is free for life, and the AI coaching is free to use. It is built and run by one engineer on lean infrastructure, which keeps costs low.

How does the Garmin integration work after Garmin's API changes?
Athlete Space uses Garmin’s official developer programme, and athletes sign in directly with Garmin, so Athlete Space never sees their Garmin password. Activities arrive when the watch syncs with Garmin Connect, and planned workouts go back as structured workouts that appear on compatible watches after the next sync.

Can I disagree with the coach?
Yes. Athletes can ask questions, explain changes in their availability and ask for a different arrangement. The coach explains its decisions and rebuilds the schedule around the athlete’s instructions.

Sports and connected devices

Athlete Space covers these sports, alone or combined:

• Running, from 5K to marathon and ultras, including trail and treadmill.
• Cycling, road and indoor, including gran fondos, centuries, time trials and road races.
• Swimming, pool and open water.
• Triathlon, with all three sports planned together.
• HYROX, combining running and station work.
• CrossFit and strength training, alone or alongside endurance training.

Hikes and walks can also count towards the training week. These are the services it connects to:

On Garmin, Athlete Space works through the official developer programme, so activities come straight from Garmin Connect and planned sessions go back through Garmin’s Training API. Activities from COROS and Suunto watches reach it via Strava.

Built by an athlete who knows the problem

Artacho runs Athlete Space on his own from Nashville, Tennessee. He holds a PhD in artificial intelligence and spent several years building production AI systems at Amazon and Google. He is also an endurance athlete, with several Ironman finishes, a best of 9:01, and an age-group win and fourth overall at Ironman Maryland that earned a place at the World Championship in Kona.

Athletes now collect huge amounts of training data, but having the data and knowing what to do with it are different things. Athlete Space is meant for athletes without a coach, for whom it provides day-to-day guidance, and for coached athletes, for whom it takes over the admin of reviewing sessions and rebuilding weeks. As a one-person product, feedback goes straight to the person writing the software.

More information: athletespace.ai.

Author: Bruno Artacho, founder of Athlete Space, edited by the5krunner.

If you enjoyed reading this, here is another in the Indie Spotlight series: Indie App Spotlight: VMAX running plans come from a coach, not AI.

Last Updated on 11 November 2026 by tfk the5krunner

tfk the5krunner

tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors. See the gear tfk uses. ID