LewisBirchenough

My max HR measured a few years back (at age 31) was around 205. I'm now 33 and I just did a half marathon with an average HR of 189. I can't say I felt great at the end, but my legs hurt more than my cardiovascular system.

I agree that equal volumes would (should) be assumed, and that this is really all about semantics. On the other hand, I just think, why say "muscle weighs more than fat" (with equal volumes implied) when you can use the more precise language "muscle is more dense than fat"? Using density removes any need to assume equal…

If there are parts of your route where there isn't a clear view of the sky (e.g. due to foliage etc.) then a GPS method might not be totally accurate since GPS works by picking up signals from satellites to calculate distance.

x2

P.S. MHR is not some target rate you are aiming to stay below, but is the absolute highest heart rate that it is physically possible to achieve. If your heart rate exceeds your supposed MHR at any time, then the figure you have for your MHR is wrong by definition.

See rebysue's answer above referring to averages (except that I don't think actual MHR depends on fitness, but rather is genetic). The 220-age is a guestimate which can be way out: e.g. my MHR at age 30 was at least 205.

How did everyone do? I exploded in the second half!

I'm doing it, but a knee injury in the last week and a half might mean I have to crawl around! It seems a bit better now so hopefully I can make it.

Speed set to 7 mph or km/hr?

I've borrowed the 405 from a friend and have been using it quite a lot. I like that it measures distances and that you can download run data to a computer, but I don't like the bezel design much. I think they've gone for aesthetics over practicality. The bezel can be much too sensitive, more so when you're a bit sweaty,…

Doing a 5k every day of the week equals just under 22 miles per week. That's not particularly high for a 'serious' runner, but is quite a lot for someone starting out. If you're regularly running that kind of weekly milage already then it's okay, but if not, you're risking an injury. It's best to increase milage gradually.…

Didn't have to stand on the way home. :-)

The formula “Maximum Heart Rate = 220 – age” ONLY provides a very rough ESTIMATE – it is based on a statistical average for the population as a whole. An individual’s maximum heart rate is very dependent on genetic factors (not only age) and so can vary widely between different people of the same age. For example, my…

I absolutely take your point that in language there’s often meaning not explicitly expressed, and I’m sure everyone knows what is meant by “muscle weighs more than fat”. I just think, why use “weight” when you can use the more accurate word “density”. Each to his own I suppose. Onto more interesting discussions about…

It depends how big the feathers and bricks are (i.e. how much volume they have). What about a tiny tiny tiny tiny brick, and a really really really really big feather? That's why you need to specify volumes to compare the weight of different substances (density is useful because it combines weight and volume into one handy…

Yep, I agree, "density" is the correct word, not "weight". Muscle is more dense than fat. The technical definition of density is "mass per unit volume". To a physicist, mass is different from weight, but the two can be read synonymously for the purpose of this discussion. Density effectively means the weight of a given…

I'll second that comment on getting the right shoes. When I first started running, I used some totally inappropriate trainers, got injured very easily, and spent a lot of wasted time trying to recover. I then got some proper running shoes and haven't had a serious injury since.

The last time I was in decent shape was a couple of years ago when I got loads of comments about being too thin and looking unhealthy. The problem I have is that I lose off my face well before my stomach, so when I lose the stomach, I tend to look a bit emaciated in the face. It didn't bother me that much though as I knew…

... and max HR drops with age (approx 1bpm per year).

P.S. I don't think there is a correlation between max HR and fitness. It's genetic.

A couple of things to consider. First, the "Max HR=220-age" equation is only a (very) rough guide. For example, my Max HR is more than 15bpm greater than that given by the formula. For others it may be signicantly lower. You can only really find your max HR by doing a fitness test involving increasing the level of exertion…