A question about Lymphedema

Agada, there is no evidence to show that exercise prevents LE, but there is a strong association between exercise -- including strength training -- and reduced risk of LE for those as risk, and reduced incidence of LE flare-ups for those who have been diagnosed with LE.  Association means the relevant studies point to reduced risk, but the risks remain nonetheless. 

Having said that, there's a whopping huge common-sense relationship between exercise and LE.  Muscle movement against the lymphatic vessels is what pulses the lymphatic fluid (lymph) through the lymphatic system.  So movement of muscles promotes lymph movement.  Strain of any kind--including picking up something too heavy for the limb or trunk--signals 'need help' to the lymphatic system, which in turn sends more lymph to the rescue. So--here's the common sense--doesn't it seem logical that if we condition our limbs and our trunk to be able to bear heavier loads, the lymphatic system will in turn not get so excited when we lift, push, or pull something heavy?  The exercise studies of resistance training are showing that this bit of common sense does indeed translate to reality.

Exercise can bring its own LE risk, though, so we have to work on getting its benefits while minimizing those risks.  Raising the core body temperature signals 'stress' to the lymphatic system.  Lifting a dumbbell that's too heavy (haven't worked up slowly to that weight) signals 'stress.'  Repetitive arm motions (like rowing) signal 'stress' to the lymphatic system.  So--be careful about exercising in very hot conditions; drink lots of water to rehydrate; wear wicking fabrics; get in a swimming pool for exercise; follow safe weightlifting guidelines that include adding weight in small increments and avoiding bodyweight or resistance-band exercises where we cannot measure the amount of weight load (nor add to it in small increments).

Patients with LE wear compression sleeves and gauntlets or gloves while exercising and weight lifting.  At-risk patients without a LE diagnosis should consult with a lymphedema therapist to help decide if compression is needed.

On the rowing, my common-sense answer is to get the trunk and arms nice and strong before doing any extensive rowing, so that the unavoidable repetitive motion is tempered by having plenty of strength to push/pull the oar/paddle.  I just completed a five-day kayak trip, paddling as much as 7 hours a day, and I am convinced that my LE would have exploded on me had I not been following an LE-safe weightlifting program (PAL Protocol-compliant) for six months.

Would rowing or other exercises ever cause LE?  I don't think we have an answer on that.  If you are already at risk from BC treatment and surgery, and especially if you are pre-clinical (no visible swelling, but the arm can have up to 30% extra fluid without visible swelling), rowing or similar hard-work exercise might be that straw that break's the camel's back.  (Funny saying, now that I think of it--camel retains water in the hump...).  Or, you might unfortunately be genetically predisposed to getting LE (research supports that), and while the rowing might precipitate the onset of LE symptoms, it would not technically be the cause.

Clear as mud, no?