Matt Metzgar

Are Bras Healthy?

Recently, a reader asked me about whether bras are healthy, given that hunter-gatherer women obviously didn't wear them.  I have to confess that, being male, I've never even thought about the issue.  But I am always up for a challenge and did some research.

First, I was surprised to see a book out, "Dressed to Kill", that presupposes a link between bras and breast cancer.  Of course, there are books on any subject - aliens, tarot cards, etc. - and a book by itself does mean something is credible.  But from the abstract of the book and some other sources, the theory struck me as very intriguing.

The best summary of all evidence I found is here.  Another summary is here, and the author addresses things from an evolutionary perspective.  He mentions that women evolved under conditions where there was natural breast movement throughout normal daily activities.  The movement could be equated to a daily "massage" for the breasts.  This would agree with recent research that shows for women diagnosed with breast cancer, breast massage increases the activity of natural killer cells.

The bottom line is that there is currently no cut-and-dry evidence that bras are related to breast cancer.  However, viewing the issue from an evolutionary perspective certainly suggests that daily, natural breast movement is healthy, and that bras may restrict this. 

More Benefits from Fasting

Previously, I have posted about the benefits of intermittent fasting as a way to improve health.  A new research paper now shows even more benefits from fasting, particularly in relation to growth hormone.

This article discusses how food intake during human history was often spotty, and how "feast or famine" was frequently the norm.  Over time, the body adapted to these conditions, and has learned to function efficiently in their presence.  One of the key adaptations to food unpredictability is the response of growth hormone.

Growth hormone has been hailed as a "miracle drug" for its ability to burn fat and increase muscle in normal subjects.  These subjects don't even have to perform any exercise at all - just the injection of growth hormone itself is enough to favorably alter body composition.  It is even rumored that aging Hollywood superstars have turned to growth hormone injections to stay young-looking.

The research papers discusses the relationship between food intake and growth hormone and makes one thing clear: brief fasting will cause a large increase in growth hormone.  In fact, in one study subjects fasting for 2 days had a fivefold increase in internal growth hormone production.

If growth hormone is the "fountain of youth", this study shows that it is available to everyone.  Through brief periods of fasting, a person can increase his or her own growth hormone levels, without the need for drugs and the adverse side effects.

My Current Workout

I am posting my current workout here because it is working so well for me right now.  It is the result of much experimentation, and is providing me with good energy levels and health.

Day 1 - (Sunday) Tabata interval training, medicine ball, walk 30 minutes

Day 2 - Walk 1 hour

Day 3 - Walk 1 hour

Day 4 - Tabata interval training, weight workout, walk 15 - 20 minutes

Day 5 - Walk 1 hour

Day 6 - Walk 1 hour

Day 7 - Walk 1 hour

As you can see, this routine has a couple of brief sessions of high-intensity work per week along with lots of walking.  Why only two days of high-intensity work per week?  I have found through trial and error that anything more for me will lead to overtraining.  In fact, every fourth week of this plan, I skip the normal Day 4 workout and substitute an hour of walking, essentially taking a week off from vigorous activity.

Here's some more detail on the workout.  The Tabata interval training consists of 20 seconds hard sprinting followed by 10 seconds rest.  Then repeat.  I currently do 8 repetitions, all in row, so the actual workout part only takes about 4 minutes.  Afterwards, I throw around a 6 lb medicine ball to engage the upper body more.

The weight workout is also brief, around 20-25 minutes.  Currently, I am trying some heavy single reptitions followed by one set of high-repetitions for each exercise.  More on this in a future post.

Why so much walking?  Hunter-gathers walked a great deal, approximately 9 miles a day.  So 1 hour of walking (about 3 miles) is getting off easy!  Plus, walking is a great way to burn fat and has all kinds of other health benefits.