It depends. Sometimes yes, sometimes no. With sports like basketball, handball or volleyball, I don't like to use strobes. It's too much action to depend on single shot only. With sports like skateboarding (I don't shoot much skateboarding, but it's similar to other sports I shoot more so..), there's one guy only, with no interaction with someone/something else, and it's pretty predictable, so single shot is not that bad. For beginning, I agree it will probably get hard to get right timing, but you get used to this pretty fast. And it's same for every sport... without knowing sport good enough, it's extremely hard to get right timing.
On top of that, there are external battery packs for on-camera flashes, and you can get few shots in row even on 8fps with that. But it's different story, and definitely not something I would suggest to buy for someone with camera and one lens. And please, don't understand me wrong, I don't mean anything bad with it, it's just that there's more important things to get before you get battery pack.