Confused on HealthKit data types

Having a tough time here figuring out HealthKit data types. I’m building a fitness app and wanted to tap into traditional strength training. Found a guide that had DistanceCycling in there. Tried following the guides over on devdactic and when I swapped it out, it crashed.

saveWorkout() {
    let woDuration = this.item.time * 60;
    let workout = {
        'activityType': 'HKWorkoutActivityTypeTraditionalStrengthTraining',
        'quantityType': 'HKQuantityTypeIdentifierActiveEnergyBurned',
        'startDate': new Date(), // now
        'endDate': null, // not needed when using duration
        'duration': woDuration, //in seconds
        'energy': this.hkCals, //
        'energyUnit': 'kcal', // J|cal|kcal
        // 'distance': 5, // optional
        // 'distanceUnit': 'km'
    this.healthKit.saveWorkout(workout).then(res => {

Here’s the error from xcode:

Terminating app due to uncaught exception ‘_HKObjectValidationFailureException’, reason: 'HKQuantitySample (2018-09-21 21:45:14 -0400 - 2018-09-21 22:45:14 -0400) requires unit of type Energy. Incompatible unit: (null)'

anyone have any experience with implementing HealthKit?

It looks like the variable for energy is null or undefined. Where are you setting that?