Tag Archives: trek tri island

A New Study for COPDers: Mechanism of Greater Oxygen Desaturation during Walking Compared with Cycling in COPD.

Do COPDers desaturate more walking than they do cycling?  I’ve said ever since I discovered the recumbent trike existed that the recumbent trike was God’s gift to the COPDer…indeed, anyone with physical limitations.

Pedaling around the bay from the ferry on Whidbey Island with the American Lung Association of Washington’s Trek Tri Island three day cycling trip one early morning a few years ago was the first time I felt ‘normal’ again in about 7 years and the same length of time I’d gone anywhere overnight since a stay in Harrison Medical Center in 1997.

In those days I didn’t have a hip problem so I could walk without a problem other than shortness of breath but the recumbent trike lets us take our comfortable seat everywhere we pedal and stop whenever we need to take a break.  It also builds the legs muscles better and faster (my opinion) than walking and it is sure more fun and faster.

My point is wondering what the following study means in practical terms – to us, the patient.  I am one of those who do not desaturate enough for oxygen while awake.

Is cycling less strain or easier on our lungs than walking?


“Chest. 2011 Jan 27. [Epub ahead of print]

Mechanism of Greater Oxygen Desaturation during Walking Compared with Cycling in COPD.

Mahler DA, Gifford AH, Waterman LA, Ward J, Machala S, Baird JC.

1 Section of Pulmonary & Critical Care Medicine Dartmouth Medical School, Lebanon, NH, USA.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) exhibit greater oxyhemoglobin desaturation during walking than with cycling. The purpose of this investigation was to investigate differences in ventilatory responses and gas exchange as proposed mechanisms for this observation.

METHODS: Arterial blood gases and lactate were measured in 12 patients with COPD (age, 68 ± 6 years) during incremental treadmill and cycle exercise. The primary outcome to assess the ventilatory response to exercise was the partial pressure of alveolar oxygen (P(A)O(2)). The primary outcome to assess impairment in exercise gas exchange was the difference between partial pressures of alveolar and arterial oxygen (P(a)O(2)) (AaPO(2)).

RESULTS: P(a)O(2) was significantly lower at peak exercise for treadmill walking (51.4 ± 6.8 mmHg) compared with cycling (60.4 ± 10.7 mmHg) (p = 0.002). The initial increase in P(A)O(2) with cycling occurred prior to the onset of the anaerobic threshold. At peak exercise, P(A)O(2) was significantly higher with cycling compared with walking (p = 0.004). The anaerobic threshold occurred at a lower VO(2) during cycling than walking (p = 0.001), and peak lactate levels were higher with cycling (p = 0.019). With progressive exercise, AaPO(2) increased similarly during treadmill and cycle exercise.

CONCLUSIONS: The higher P(A)O(2) during cycling minimized the magnitude of oxyhemoglobin desaturation compared with walking. The enhanced respiratory stimulation during cycling appears due to an initial neurogenic process, possibly originating in receptors of exercising muscles, and a subsequent earlier onset of anaerobic metabolism with higher lactate levels during cycling.”

PMID: 21273296 [PubMed – as supplied by publisher]



I do not have a financial interest in any bike company including the recumbent trike.

More later…. Sharon O’Hara

A Recumbent Trike Legs and Lung Beginning

Chronic patients are lucky, too.

I have a story to tell about this year’s 2009 American Lung Association of Washington’s Trek Tri Island’s three-day bike trip – but to tell it, you need to understand the beginning first.
I hope I am permitted to do this…the story is not about me, it never has been.
It is a story about a person who went from fit and health and physically active into a patient who couldn’t breathe and thought she was dying.
Sharon’s Ride
September 2005
A dream come true. I worked hard for pledge dollars and LOVED EVERY MINUTE of it. For the first time since 1997 I dared to go on a trip… and had no idea how I would manage without my BiPap, my water pills … put up a tent, take it down… carry my stuff around…

At the start I felt like a breathless beached whale… wondering what I was doing with a group of – clearly – fit people on a three day American Lung Association of Washington three day bike ride on a trike I’d never ridden before. It seemed all my exercise work wasn’t enough. EFFORTS – thoughts of EFFORTS – all you – kept me going!

The outstanding help and assistance I received from the volunteer crew enabled me to keep going, but it was a fellow trike rider, Dan… who must have seen I was struggling and rode up behind and asked if he could help. He patiently taught me how to shift gears, including the big gears until I could ‘feel’ the shifting… as well as see the speedometer computer jump to reflect speed… proof to me shifting pays off.

COPD has given me the opportunity to slow down and discover incredible kindness of folks that I never had time to notice before. EFFORTS gave me my life back – exercise lets me function…

Ferry schedules are kept – ferries wait for no one. The outstanding volunteer group helped me ‘keep up’… in particular, Don.

On the last day Don drove me and my trike far enough out to get a head start and I began pedaling the final 19.2 miles into Victoria B.C. and the Victoria Clipper. Pedaling up hills I stopped whenever I needed to – sometimes every couple of feet – for a minute or two. I sat on my trike until I could go again.

Foot by foot I pedaled to the top of the hills and barreled down the other side. Until…close to Victoria – a hill came into sight that appeared almost vertical. I couldn’t see the top. I stopped when I got to the bottom and stared up. I was outfaced. If I started up I couldn’t stop to rest until I got over it. It was steep, yes, but I was too close to stop now. I started up.

The top of the hill got closer until I was just below it my legs shook from the strain and I couldn’t breathe – I labored to keep going. All of a sudden the trike felt light and we raced upward. A voice yelled, “Keep pedaling”!

My feet flew –we hit the summit and started down the other side. I yelled back, “Thank you!” Someone saw I was in trouble and pushed me up! I let the trike race down until I could pedal and breathe again and my heart quit jumping and thumping.

It was Don one of the ALA of WA’s extraordinary volunteers … I’d passed him parked on the side of the road several times during the 19.2 mile ride. He’d ask if I wanted to stop? I”d answer, “No, I’ll keep going for now.”

Thanks to many people I rode my trike 19.2 miles into Victoria and when I got there I couldn’t stop tears from welling behind my sunglasses.

You did it, EFFORTS. You taught me how to live again, gave me my life back. And to see the bright red EFFORTS tee-shirt and meet the man inside, Chris, EFFORTS Ambassador to Canada and his lovely wife was pure joy. Chris is so EFFORTS oriented, so energetic, so giving… he gave me his watch when I said I didn’t have one. And our watch says it is now 3:49pm.

God Bless. Thank you for helping me live again. EXERCISE FOLKS please help yourself…. and join me next time?
Sharon O’Hara

More later… Sharon O’Hara