Hey friends, how's the burpee challenge going? Today I've got some modifications that will be perfect if the burpees haven't been agreeing with you, or if you're doing fine but you'd like to rope in a friend who has some doubts.

A month is a short time. Even by the end of our flexibility challenge, you may not find that you've made a ton of progress. But every little bit helps, and it's inspiring to see the progress of people who have been working on their stretching for years.

Our past two challenges were all about getting stronger, but this month we're going to do something a little different. We're getting stretchy.

Can you believe it's only a week until we complete our fitness challenge? Don't panic -- we have a great way for you to test your mettle for the final day, and it's part of a simple, doable workout.

Sick of running yet? We hope you're not, but either way, here's a new challenge for you. We're going to do a mini strength workout that is not tied to running. You can even work out indoors if you feel like it.

How's the Lifehacker Fitness Challenge treating you? If you're logging a ton of kilometres, great -- but if you've slacked off a bit or are just joining us, that's fine too. This week's workout is for everyone. We're going to run some tiny solo races, and they will make you faster.

You've set your goal and hopefully gone for a few runs by now. (If not, it's never too late - look out for our guiding on starting later today!) Now it's time to take a closer look at how you run. Fix your form now, and you'll be able to run smoother and faster in the future. We'll start with something simple: Count how many steps you take per minute.