Heart Palpitations or Anxiety After Exercise | Carbohydrates

Exercise Advice for Heart Palpitations or Anxiety Triggered by Working Out

Post-exercise palpitations and anxiety are often a predictable outcome of low carbohydrate availability + high training stress. Fix the input, normalise the response.

If your experiencing :
• Heart racing or irregular beats post-session
• Sudden onset anxiety after training
• Shakiness, “wired but tired” feeling

This is often written off as intensity or conditioning. In reality, one of the most common drivers is low carbohydrate availability.

When carbohydrate intake is insufficient relative to training demand:

→ Blood glucose drops (or becomes unstable)
→ The body increases catecholamine output (adrenaline/noradrenaline)
→ Cortisol also rises to maintain energy availability
→ This creates a sympathetic-dominant state

Result:

Palpitations, heightened heart rate, anxiety-like symptoms It’s a fuel-mediated stress response.


Additional contributing factors:

• Low glycogen → greater reliance on stress hormones during/after exercise
• Dehydration → reduced plasma volume, increased cardiac strain
• Electrolyte imbalance (especially sodium, potassium, magnesium) → altered cardiac excitability
• High caffeine intake layered onto low fuel → amplified sympathetic response


Important: protein is not the limiting factor here.
Adequate protein supports recovery, but it does not address:
• Glycogen depletion
• Blood glucose regulation
• Nervous system stress

You cannot compensate for low carbohydrate availability with higher protein intake.


What this looks like in practice:

You train fasted + caffeine →
elevated catecholamines during session → post-exercise crash + palpitations

You follow a chronically low-carb diet →
increased stress hormone reliance → post-training anxiety

Most common: You consume only protein post-workout →
delayed glycogen restoration + prolonged sympathetic activation


Post-workout priorities:

Carbohydrates (primary) → restore glycogen, stabilize blood glucose, reduce cortisol Protein → support muscle protein synthesis

Fluids + electrolytes → restore plasma volume, support cardiac function

General targets:
• Carbs: ~0.5–1.0 g/kg (depending on session demand)
• Protein: ~20–30 g
• Include sodium if significant sweat loss


Examples:

• Banana + Greek yogurt
• Rice + lean protein + vegetables
• Oats + protein + fruit
• Smoothie (fruit + protein + electrolytes)

Personally I drink an electrolyte drink whilst training, Eat an apple or orange immediately after training. And an hour later I have a smoothie with banana and protein if out and about, or eat a full meal with balanced carbs and proteins. If I trained hard that meal will be high carbohydrates such as a jacket potato or pasta which will help recovery and reuce soreness.