Run smart on hot days: Choose a cool place and have plenty of water before you start, as running is more challenging when the temperature is above 28 C. Provided to Shanghai Star

Summer running can be challenging because the high temperatures cause excessive sweat and the body loses more nutrients than usual, raising the risk of heatstroke and heart disease.

Yang Jun, an associate professor and middle-distance race coach of Shanghai's Fudan University, gives us tips on how to run safely and healthily in hot weather.

Q: How long should you run?

A: Runners may feel discomfort when the temperature is above 28 C, so it is best to run early in the morning or at night. Amateur runners should not exceed 10 kilometers in a single session while experienced runners can increase their distance but should not exceed 20 kilometers.

Regardless of temperature fluctuations, you should maintain at least three running sessions per week.

When should you stop?

Stop to take a rest immediately if you feel breathless or dizzy or if you experience tinnitus, the inability to control your muscles or if you stop sweating suddenly. Take rest at a cool and ventilated place and have some fruit and carbohydrates.

It is a good habit to wear a heart rate monitor strap while running. Normal adults' heart rates are between 60-100 beats per minute. Slow down if your heart rate is more than 160 beats per minute.

What should you wear?

Clothes made of fast-dry fabrics are most recommended. Pure cotton clothes, though comfortable, will get wet through and may harm the joints in the long run.

Apply sun block when participating in long-distance races in the summer to prevent sunburn and skin disease. Caps and sports sunglasses with UV protection are also necessary.