Sounds like a fun project. Start by sketching a simple model: a PushUp class, a Session tracker, and a HealthSensor interface for heart‑rate and macros. Use an event bus so the UI can subscribe to updates. Then write a lightweight scheduler that calculates the optimal shake time based on the last push‑up set and your RHR. Once the core logic is clean, hook up the UI—maybe a tiny React or Flutter front‑end. I can walk you through the first steps if you’re up for it.

class PushUp: def __init__(self, weight=0.0): self.count = 0 self.sets = 0 self.weight = weight self.start_time = None self.end_time = None def start_set(self): self.start_time = time.time() self.count = 0 def log_repetition(self): self.count += 1 def end_set(self): self.end_time = time.time() self.sets += 1 duration = self.end_time - self.start_time print(f"Set {self.sets}: {self.count} reps in {duration:.1f}s") self.start_time = None self.end_time = None # Heart‑rate sensor interface class HeartRateSensor: def __init__(self, provider): self.provider = provider # e.g., "Fitbit", "AppleHealth" def get_current_rate(self): # placeholder for real API call return self.provider.get_heart_rate() # Shake timer logic class ShakeScheduler: def __init__(self, sensor, interval_minutes=30): self.sensor = sensor self.interval = interval_minutes * 60 self.last_shake = time.time() def should_shake(self): return time.time() - self.last_shake >= self.interval def trigger_shake(self): if self.should_shake(): print("Time for your protein shake!") self.last_shake = time.time()