You can fly at a height of up to 6ft/2m above the ground. You can propel yourself in any direction midair, expending energy at the same rate as the corresponding running speed, but without straining any muscles (so you will be tired but not sore). You will be fully subjected to drag and will be based on air speed, not ground speed. That means you could coast along all day at 20mph/30kmh in a strong tailwind, or get thrown backwards by a strong headwind.

OR

You can jump up to 30ft/9m high. You will also be able to comfortably land from that height. Jumping higher will require more work from your legs, and the highest jumps will leave your legs immediately quite sore. You will have control over how high you jump. You're not gonna be immobilized, but you are gonna feel it for the rest of the day. This only benefits your vertical, your horizontal will only be affected by increased air time to travel forward at the same speed as before (you'll be moving longer, not faster).