Competitive Opportunity

While not as much an issue at collegiate levels, elite female athletes may find difficulty finding as many opportunities to compete as their male teammates.

Nordic Skiing

At the most elite level, Nordic skiing is very gender equal. The number of athletes per gender each nation is allowed to send to each race is determined by a qualification standard and a team quota, and in many cases has resulted in more female athletes competing for a country than male.
And while each World Cup weekend is dual gender, each gender races a different distance, where in some cases the women will race only half the distance the men do in any given race.

Cycling

At the WorldTour level, cycling still has a few problems when it comes to equal competitive opportunity. Women's races are drastically shorter than the men's races, teams are significantly smaller, and there are less than half as many racing days for women as there are for men. And it trickles down.

Running

The most equal of the three, elite endurance (or for that matter, any) running events, whether it's a track meet, marathon, or cross country event, see men and women competing at the same distance more than 90% of the time.
Currently, the only differences in race distances are at the sub-Senior levels of cross country events, where international junior women compete over a 6km race, and junior men over 8km. This is also seen at the NCAA level in the United States, where women mostly compete at either 5km or 6km, and men at 8km or 10km.