I wish I could leave a longer and more favorable review, but I don't recall a lot of this book because it frankly wasn't very memorable. With the wealth of material Heinrich has to work with, the book should've been more compelling. But this short memoir is unfocused. The title leads readers to believe it will be primarily about running and, more specific, running across one's entire lifespan and how age slows runners. It is only partly about these topics. "Racing the Clock" also touches on Heinrich's childhood in Germany during the war, his emigration to the US, college in Maine and at UCLA, the temperature regulation of insects, training for ultramarathons, attempting to break running age-group records. All these are interesting topics. Heinrich's unique upbringing in a cabin in Bavaria, dirt poor, focused on insects, would be enough for a full-length book. And he writes about his passion for nature with such conviction that it draws the reader in, even when he's describing things like termites or honeybees. But "Racing the Clock" is barely 200 pages, so Heinrich merely flits from one topic to the next. Runners will be disappointed by the dearth of running-related material here. I think that's the main problem with this book: expectation. An editor should've kept Heinrich to a more narrow outline. The author tries to wrap everything around training for a 100K race at age 80, but this event slips into the background. And strangely, when he runs a trail race in old age, he seems surprised that trail running is even a thing. By the last few pages, Heinrich has slipped into generalities about how we are all one and how we share the earth with all other creatures. I don't necessarily disagree - this just seems like a less than fitting way to end a memoir by a truly unique man who struggled through trying circumstances in early life to become a great runner and great scientist.