A high-neck racerback bikini top is your best bet.

Yes, they exist—but you have to look for athletic-specific designs, not fashion bikinis.

Regular string bikinis bounce loose the second you pick up speed. You need compression fabric, wider straps, and a cut that actually holds your chest in place. High-neck styles work well because they distribute force across your shoulders. Racerbacks keep straps from sliding off. Look for tops labeled “sports” or “active” from brands that make actual swimwear—Speedo, Nike, Athleta, Roxy.

If you’re well-endowed, underwire or soft-cup padding helps too. Adjustable straps and a clasp back are bonus points for a custom fit.

Don’t bother with triangle tops or bandeaus. They’re for lounging, not jogging. You’ll spend the whole run readjusting instead of enjoying the sand.

Your boobs will thank you later.