public async Task <bool?> UpdateWorkout(int userId, int workoutId, PlannedWorkoutVM updatedWorkout)
        {
            await Extensions.FindUser(userId, _userRepository, _cache);

            var workout = await _plannedWorkoutRepository.Get(workoutId);

            if (workout is null || userId != workout.UserId)
            {
                return(null);
            }

            if (workout.DatesAreEdited(updatedWorkout))
            {
                throw new RestException(System.Net.HttpStatusCode.BadRequest, "Date information cannot be changed in this request.");
            }

            workout.UpdateFromVM(updatedWorkout);
            return((await _plannedWorkoutRepository.Update(workout)) > 0);
        }