After you've finished 30 minutes of cardio and lifted the last rep of your last set, what's left to do? Go home? Not quite. Here are four must-dos after every workout.

Cooldown

A solid heart-pumping cardio workout means you've raised your heart rate close to your maximum (220 minus your age equals the recommended maximum beats per minute). So you need to do at least five minutes of light exercise to safely bring it back down to your resting heart rate (about 60 to 80 beats per minute). Whether you're running, biking, swimming, or taking a cardio class, slowing down your pace for the last five minutes is the perfect cooldown.

Photo: Leta Shy

Hydrate

Depending on how intensely you exercised and how much you sweat, you need to replenish lost fluids to prevent dehydration and dizziness. Water is fine if you exercised for under an hour, but if your workout was much longer or you sweat a lot, go for a sports drink or this monkey flip recovery smoothie made with coconut water.

To figure out how much to sip, here's a fun little trick: Weigh yourself before and after your workout. For every pound of water weight lost, replace it by drinking 16 to 20 ounces of water or sports drink. Another good way to monitor that you've gotten enough water is in the ladies room. If you have a large amount of light-colored urine, then you're hydrated. If it's dark, then you'll know you need to drink more before, during, and after your workout. Sip your beverage slowly to help your body hydrate more quickly.

Stretch

Don't skip the stretch session because you're short on time. It'll not only prevent post-workout soreness, but supple muscles are also less prone to injury. Hold stretches — don't bounce, and push to the point of feeling a good stretch, not to the point of pain. Here's a post-run stretching sequence that's perfect for any workout. It targets the hamstrings, hips, and lower back — common areas of tightness for most exercisers. And here's another sequence to increase flexibility in the spine and shoulders.

Eat

If you're exercising to lose weight, it seems counterproductive to eat after burning calories. But don't worry — eating doesn't cancel out the calories you just burned. That's because while working out, your body burns fat for energy. The healthy calories you consume after a workout won't replace that burned fat, they're used to repair and refuel.

If you're not due for a meal, your post-workout snack should be around 150 calories, and contain a bit of protein to help rebuild muscles and carbs to offer energy. Aside from basic snacks like these, you can get a little creative and whip up these homemade low-cal post-workout snacks. Eat immediately after your workout.