Running outdoors-sweat & rain iPhone 7?

depends on how hard you sweat and what type of food you eat. 🙂

Apple provides this document on cleaning your device

Cleaning your Apple products - Apple Support

Cleaning your iPhone - Apple Support

iPhone 7 and iPhone 7 Plus

Clean your iPhone immediately if it comes in contact with anything that may cause stains, or other damage—for example, dirt or sand, ink, makeup, soap, detergent, acids or acidic foods, or lotions. Follow these guidelines:

• Unplug all cables and turn off your iPhone (press and hold the Sleep/Wake button, and then slide the onscreen slider).
• Use a soft, lint-free cloth—for example, a lens cloth.
• Avoid getting moisture in openings.
• Don’t use cleaning products or compressed air.

Your iPhone has a fingerprint-resistant oleophobic—oil repellant—coating. This coating wears over time with normal use. Cleaning products and abrasive materials will further diminish the coating and might scratch your iPhone.

The iPhone 7 is water resistant, but not water proof, so some caution would be warranted with an expensive device. Sweat is far more corrosive than pure water since it has all sorts of salts, proteins and other compounds in it. It is also more damaging to things like lens coatings and such than simple water, for the same reasons.

So while I'm not saying to baby it, I also wouldn't soak it in sweat either. Every water and sweat resistant BT headset I've ever used has failed within 10-18 months of daily use due to sweat and corrosion. Resistance does not mean the device is immune to the effects of long term or continued exposure.

Note too that the water resistance does degrade some over time - so the device is a bit less and less water resistant inherently as it ages. The rating is really intended to protect against occasional and unintended brief exposure to water, not provide for regular exposure to water as a normal course of your daily use. Finally, note too that despite the rating, water damage still voids the warranty.

iPhone 7 is designed to be water resistant. I'd imagine it'll survive being sweated upon. Take a look:

About iPhone 7 and iPhone 7 Plus splash, water, and ... - Apple Support