Base Builder

Base Builder
App Store

Aerobic base training custom alerts

About Base Builder

Base Builder provides you with configurable alerts and status updates to help you stick to your training plan.

Configurable voice and haptic alerts enable you to spend more time focusing on your workout and less time looking at your watch.

Base Builder Heart


Heart Rate Alerts

Upper limit and recovery notifications keep you at your target heart rate.

Distance Based Status Updates

Get status updates as often as you want.

Update frequency is configurable based on distance.

Voice or Haptic Feedback

Voice and haptic alerts keep you informed of your workout status.


Why another app?

I have been a long time Apple Watch user and runner. Long training runs with no phone is incredible. But when it came to aerobic base training (lactate threshold), I was never able to find an app that worked for me.

I tried apps that would alert you when you entered and exited certain heart rate zones. But I found that these alerts were easily missed and I had to constantly look at my watch to know if I was at my target heart rate.

Long runs are also a great opportunity to catch up on podcasts or listen to music. The missed notification problem was even worse while listening to audio with these apps.

Base Builder aims to fill this gap.

What I needed in an app

Some of the key features that I was looking for in an aerobic base training style workout app were:

  • Easy to identify heart rate. On these base building training runs, heart rate is my most important metric.
  • Primary interaction points are audio and haptics. Once the app is setup and running I do not want to have to constantly be looking at my wrist.
  • Audio volume is lowered (podcasts paused) when in alert mode. I want to know as soon as I'm over the heart rate limit.
  • Audio feedback for how far I've exceeded the heart rate limit.
  • Steady heart rate audio updates so I can adjust effort to reach the desired effort.
  • Workouts must be saved in HealthKit so I can visualize workout data in any app and keep a long term record for myself.

  • How I use Base Builder

    One goal of aerobic base building workouts is to train for an extended period of time at low-ish heart rates (should be able to hold a basic conversation). I set my heart rate limit, start running and wait for notifications.

    If it's a regular heart rate update notification I will know if I should increase or maintain my current effort. If it's an alert indicating that I've exceeded my heart rate limit I will either slowdown or start walking depending on how high above the limit I am and whether or not I'm headed up or down hill.

    Once I receive the heart rate recovery notification I will pick up the pace again and get back to my normal training effort. This lower heart rate limit is configurable based on your upper limit. I set it to be 15 beats below my limit so I will have some buffer and know I can pick up the pace again.

    After an extended period of training runs its a lot of fun to look back at your historical data in HealthKit and see your pace and VO2 max improve over time all while maintaining the same level of effort.

    Base Builder helps you run slow so you can get fast!