“The work is interesting as many ethnic groups from Africa were studied and haplotypes were constructed that gave data about the migrations of the LP [lactase persistence] alleles,” Irma Järvelä of ...

Lactose intolerance affects 70% of the global population, causing symptoms like bloating and diarrhea due to insufficient lactase enzyme. While genetic intolerance is incurable, temporary cases ...

So you been sprinting, Lily? Just a bit of cramp? So that's the lactic acid building up. When an athlete does too much or runs too vigorously, not enough oxygen can be delivered to the muscles.