Runners and coaches and those involved in sport are typically on contracts with a specifically defined term. Employees who are being furloughed (in any industry) are not on such defined and strict contracts. Even without races these runners will still get paid through the end of their contracts.
The economic slump will hurt the companies who sponsor athletes, which will change (but probably not all together eliminate), how these companies invest in the athletes who represent them.
The evolving economic crises will certainly impact university and professional sports (not just track). But most athletes, whether they play in the NBA, the MLB or run on the major marathon circuit, for the time being are paid according to their contracts (which in the vast majority of cases did not account for a work stoppage like this).