The systolic pressure there of 115 is fine and normal range...
The diastolic of 45 is a bit low>> yes to that...
You note that this reading is after heavy labor and that would make sense. The blood vessels open up with exertion/exercise and this allows increased flow to the muscles.
When you are actively exercising the blood pressure rises ( normal physiological response) but then when you rest the blood pressure comes back down..
A single reading is not cause for worry here..
I suspect that both systolic and diastolic will return to normal range with additional time...
It is the AVERAGE RESTING seated BP that matters >> so continue to monitor Your average over time should fall in range of 100 to 135 for systolic and 60 to 85 for diastolic...
If you have too many lows or symptoms such as feeling light headed then you should consult your doctor and have your medicines reviewed..
I would encourage you to keep a journal of your BP readings (and pulse rate )
I hope that this information is helpful for you. let me know if you have further questions or discussion or concerns.
I will be happy to get back with you!
If my answers have been helpful and to your satisfaction then please remember to leave positive feedback. Thank You and Best Regards!
Anthony Bray MD