Dr. Lankford with the save! Yeah, my equation would come out to -190 BPM for my max HR
If you are interested in learning about training for big mountain days I cannot recommend the book
Training for the New Alpinism enough. Authors House/Johnston also use one's ability to carry on a convo easily or to carry on a convo with difficulty as an analog range for anaerobic threshold.
Many smartphones can also download free or paid heart rate measuring apps that work when not connected to cellular (these apps measure the pulsing of the blood vessels in your finger via placing you place your finger over your camera/light). In comparing the results of these apps and my Polar chest monitor the app results aren't as accurate, but they are pretty darn close. These apps aren't really a convenient way to take a rolling heart rate on your Whitney hike day, but if you are training on a budget and don't want to have to buy a heart monitor you take periodic readings on training hikes you can get used to knowing how your body feels when at different exertion levels.
