Cris LaBossiere

Cris LaBossiere
Strength training and mountain biking. My two favorites

Sunday, July 3, 2011

Vitamin D + Calcium = Reduced Skin Cancer Risk

A recent study (1) is getting a lot of attention.  Any time significant risk of the big C is reduced, people want to know about it.

The headlines say that vitamin D and calcium supplements reduce risk of skin cancer in woman.  Researchers were  not able to discover why this occurs, only that this association was observed, but only under specific circumstances.

Woman who previously had nonmelanoma skin cancer expressed an approximate 57% percent decrease risk in developing melanoma when taking vitamin D and Calcium supplements.  Woman with no previous skin cancer showed no reduced risk of melanoma when taking vitamin D and Calcium supplements.

It was not certain whether it was vitamin D alone, the vitamin D + calcium combination, or calcium alone that caused the reduced risk.

The researchers said results should be interpreted with caution and that further investigation is warranted.

Another study looking at woman in Northern Italy found a week inverse association with malignant melanoma and vitamin D intake from diet. (2)

For information on melanoma and nonmelanoma skin Cancer, go to Canadian Cancer Society

(1) Calcium Plus Vitamin D Supplementation and the Ris... [J Clin Oncol. 2011] - PubMed result

(2) Inverse association between dietary vitamin d and ... [Nutr Cancer. 2011] - PubMed result

Friday, July 1, 2011

Are You A Desaturator?

A study I was involved in (1) has shown that Exercise Induced Arterial Hypoxemia (EIAH) occurs in a greater percentage of highly trained persons than previously believed (60% compared to 50%), and also seems to occur in those who are less fit, but to a lesser degree.

While it isn't exactly clear what causes EIAH, a mild to severe decrease in the oxygen content of blood when exercising at or near maximal intensity, discovering the cause of EIAH is important as not understanding this limitation reveals our incomplete understanding the physiology cardiorespiratory function.

Our study won't have any immediate impact on thinking about how we should exercise but it does add to the growing knowledge base needed to understand EIAH.

Study subjects were pushed to their limits either on a stationary bike, treadmill, or both.  We looked at blood lactate levels, lung volume and air flow pre-post exercise, and arterial blood oxygen levels.  We were able to demonstrate that air flow restriction did not influence EIAH.

Our study was the largest of it's kind to date with 82 subjects. Go to the link below to read about what we did.


Overcoming and Preventing Common Running Injuries

Justine Routhier of CJOB gave me call to talk about this article from on avoiding common running injuries.

I like fitsugar but it can sometimes be a little light in terms of referencing where they get their info from, and a little short on content.

The fitsugar article does a decent job of describing common running injuries but left out the most recent most significant understanding of what drives most lower extremity injuries and mechanical dysfunctions in runners, that being hip muscle strength and firing pattern imbalances.  Go here for an article I posted recently on this.

Two of the best exercises for improving running form, biomechanics, and reducing risk of injury are the side lying leg raise (hip abduction), and the glute bridge.

Your best step to preventing overuse injuries is taking the time required to build a healthy tolerance to running.  It isn't true that constantly dealing with aches and pains is part of regular running, but listening in on most post run discussions in any given running group and sore shins, knees, hips, feet, and back will be all too common.

The time required to become a healthy injury free runner differs somewhat between people so make sure you take the time you need which is often longer than what others claim, and longer that what we think it should take.

Indeed it usually takes 6 to 8 months of carefully progressive exercise to overcome repetitive strain injury in runners.

The most common mistakes I see in rehab and prehab (exercises to prevent common injuries) is going too hard too soon.

I'll often have athletes calling me complaining of sore hip muscles from doing the "rehab" hip exercises.  They always reveal that they decided to 50 to 100% more repetitions and exercises sessions than I recommended thinking that more is better.

In talking to physiotherapists, other coaches, massage therapists, and sport medicine docs about this, there seems to be pretty good agreement; those doing injury recovery and prevention programs either go well beyond the recommended volume and intensity of exercise, will not complete the full program, or will not do enough.  D'oh!  Very few follow the advice to the letter, and so very few have the benefit of experiencing injury free running.

It really is worth it to be patient and take the time to do it right.  Add injury prevention exercises as part of your regular routine, don't run when tired or sore, and cut your run short when aches and pains increase.