The 10k Steps Lie – Do this instead — Transcript

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1. 0:00More and more people are paying attention to their step count.
2. 0:02Many people have the explicit goal of hitting 10,000 steps a day.
3. 0:06However, the figure of 10,000 is a conveniently round number
4. 0:10that doesn't come from any evidence based source.
5. 0:13In fact, it comes from a 1965 advertising campaign
6. 0:16from a Japanese company that sold - you guessed it - a step counter.
7. 0:22Of course, the origin of the goal does not invalidate it.
8. 0:25You come to this channel for the evidence based fitness critiques,
9. 0:27so in this video I will help you decide
10. 0:30should you be walking 10,000 steps a day.
11. 0:33This is largely a discussion of cost benefit rather than of benefit alone.
12. 0:37It is very clear that there are health benefits
13. 0:39to being more physically active, and you also burn more calories.
14. 0:42Conversely, there is no real physiological reason
15. 0:45to be less active, so generally being more active is good.
16. 0:48However, is it worth the time and effort for you to actively spend time on
17. 0:53increasing your step count for the health or fat loss benefits?
18. 0:57For fat loss
19. 0:57a higher step count means a higher activity energy expenditure,
20. 1:01meaning higher total daily energy expenditure and therefore an easier
21. 1:05time getting into an energy deficit, which is what drives you to lose fat.
22. 1:09However, the total additional energy expenditure from walking versus resting
23. 1:14or whatever else you would be doing is not that large.
24. 1:17A rule of thumb
25. 1:18that's often used in exercise science is that you burn roughly 40 extra calories
26. 1:23for every 1000 extra steps that you walk, if your body weight is around 80kg.
27. 1:29The average fit guy may therefore expect to burn some 200 additional calories
28. 1:33if they increase their step count by 5000 steps a day.
29. 1:37If we look at the real life effects here, we can see that
30. 1:39this is relatively difficult for people to adhere to,
31. 1:41for relatively little fat loss.
32. 1:44For example, in a meta analysis of 32 walking interventions,
33. 1:47that's a serious walking intervention, not just a little bit more walking,
34. 1:50the average fat loss in the studies was 1.4kg, amounting to 1.2% body
35. 1:57fat reduction.
36. 1:59In many of the studies with more moderate interventions or less
37. 2:02clear interventions such as “I'm just going to try to be a little bit more active”,
38. 2:05there was no significant effect on fat loss at all.
39. 2:08The effect of higher step counts
40. 2:10on fat loss is often smaller than you would expect
41. 2:12based on the superficial mathematics for three reasons.
42. 2:16Reason #1:
43. 2:17Unlike exercise,
44. 2:18non increase activity thermogenesis tends to increase at libitum energy intake.
45. 2:23Basically,
46. 2:24people eat more when they are more active and this offsets much of the benefit.
47. 2:28Second, there is a substitution effect.
48. 2:31When people are more active at one part of the day
49. 2:33they often reduce their activity at another time of day.
50. 2:36Part of these effects is for sure psychological, but there's also clear
51. 2:39physiological effect, namely #3: constrained energy expenditure.
52. 2:44When you increase your energy expenditure, especially when you're in a deficit
53. 2:47and you're already lean and you're already quite active, the body
54. 2:50increases the energy efficiency of all your expenditure.
55. 2:54Basically, as you get more active and you burn more calories,
56. 2:57the body becomes more efficient and tries to reduce your energy expenditure.
57. 3:01It tries to conserve energy because it doesn't want to just waste it.
58. 3:04The finding of constrained energy expenditure was quite revolutionary
59. 3:08and upset the whole linear thinking in terms of fat loss science,
60. 3:11but I already explained it in a recent video,
61. 3:13so I'm not going to go into it in too much detail here.
62. 3:15What matters for this video
63. 3:16is that the effect of increased energy expenditure on fat
64. 3:19loss plateaus over time, in part due to constrained energy expenditure.
65. 3:23So most people, they increase their step count a lot
66. 3:26and they are a little bit leaner, but not that much.
67. 3:29And they don't keep getting leaner.
68. 3:31So basically they reach a new equilibrium.
69. 3:33These exact same arguments also apply to cardio for fat loss,
70. 3:36which is why we have the sayings in fitness that you cannot
71. 3:39out train a bad diet, and abs are made in the kitchen.
72. 3:42The good news is that none of these effects
73. 3:44seem to apply to resistance training. So lifting weights
74. 3:47does not make you more hungry.
75. 3:49It does not increase your appetite, it does not have a displacement effect,
76. 3:52and it also doesn't seem to suffer from constrained energy expenditure.
77. 3:55These differences between lifting weights and other forms of exercise explain
78. 3:59why research has generally found that
79. 4:01lifting weights is more effective than you would expect, based on the rather
80. 4:05limited calorie burn for fat loss, and cardio and increased step counts
81. 4:09are less effective than you would expect based on the increased energy expenditure.
82. 4:13At this point, you may be protesting: “Menno,
83. 4:15all of your fancy papers of science...
84. 4:17I have a smartwatch right here,
85. 4:20real tech, modern tech, not your ancient papers,
86. 4:22and it's telling me that I'm burning at least 500 additional calories per day.”
87. 4:27That might be true,
88. 4:29and smartwatches these days are pretty good at tracking
89. 4:32your step count, but they are unfortunately quite bad,
90. 4:36if not to say very bad, at estimating your total daily energy expenditure.
91. 4:40The correlations between energy expenditure estimated by a smartwatch,
92. 4:43regardless of brand, and that of gold standard measurements like calorimetry,
93. 4:47range from basically nonexistent to moderate at best.
94. 4:51Multiple studies have found error rates in the vicinity of 40%.
95. 4:55That means that the total daily energy expenditure estimate, or the expenditure
96. 4:59estimate of the additional walking can be off by several hundred calories
97. 5:03a day easily, regardless of brand or how new and high tech your gadget is.
98. 5:09The reason that these gadgets simply have a hard physical constraint
99. 5:12on their accuracy is that it's just
100. 5:15measuring your wrist movement and your heart rate.
101. 5:18So when your smartwatch is detecting vigorous wrist movement and an elevated
102. 5:22heart rate, it could mean...
103. 5:24...a lot of different things.
104. 5:25You could argue
105. 5:26that it's not the accuracy of the energy expenditure estimates that you're going
106. 5:29for, it's the fact that you're monitoring something that is important,
107. 5:33and when you monitor something like your step count,
108. 5:35you automatically increase it and you improve your lifestyle.
109. 5:38A meta analysis of 32 studies on the effect of starting to monitor
110. 5:42your step count, sometimes combined with counseling or other interventions,
111. 5:45but often just monitoring your step count, resulted in an increased step count,
112. 5:50yes, over the first few months of 1126
113. 5:54steps, so about 1000 extra steps in the first months.
114. 5:57Still not that large.
115. 5:59And this decayed rapidly to 464 steps at year's end.
116. 6:04And after two years the effect was no longer statistically significant at all.
117. 6:08So if you're monitoring your step count specifically to lose fat,
118. 6:11then you're monitoring something that is of questionable importance
119. 6:13to begin with, and you're measuring it in a very unreliable manner.
120. 6:17The good news is that there is arguably a much better reason to increase
121. 6:20your step count than to lose fat, and that's the health benefits.
122. 6:23A recent meta analysis of 31 studies found that higher step counts are associated
123. 6:27with better health in almost every possible dimension.
124. 6:30Cardiovascular health benefits, all cause mortality,
125. 6:33basically all measures of your health are better in people
126. 6:36that have higher step counts than people that have lower step counts.
127. 6:39The benefits are highly meaningful, even for outcomes like depression and anxiety.
128. 6:43A step count of 7000 steps compared to a very low step count
129. 6:47resulted in a 47% lower risk of all cause mortality.
130. 6:51However, it's not the case that more is always much better.
131. 6:54There are sharp diminishing returns in most of these analysis.
132. 6:58The analysis generally converge that around a step count of 7000,
133. 7:02in this latest meta analysis around 5000 to 7000 steps per day, the benefits
134. 7:06start decreasing significantly, and there's a virtually a plateau,
135. 7:10depending on who you are and the rest of your lifestyle.
136. 7:12The people currently
137. 7:13tracking their step counts the most are the people
138. 7:15that have the least benefit from doing so,
139. 7:17because they are usually already somewhat lean and already physically active.
140. 7:21For example, a previous 2022 meta analysis found that all
141. 7:24cause mortality basically plateaued at a step count 8000 steps in adults,
142. 7:28but in elderly individuals above 60 years old higher step counts were associated
143. 7:32with better health.
144. 7:33So if you're already quite healthy, you're already lean,
145. 7:36you already exercise,
146. 7:37then the benefits of higher step counts are much less dramatic.
147. 7:40In fact, in these analysis,
148. 7:42one of the biggest confounders is that it includes exercise.
149. 7:45So when you strip out the benefits of exercise, the additional benefits
150. 7:48of also having the high step count are significantly lower.
151. 7:52Moreover, step counts are a very crude measure of someone's
152. 7:55total physical activity level for multiple reasons.
153. 7:58First and foremost, they suffer from massive reverse causality.
154. 8:02When you measure someone's
155. 8:03step count and their health outcomes, you are measuring an association.
156. 8:06This is not a randomized controlled trial over a very long duration
157. 8:09because it's simply impossible to do these things.
158. 8:11So when you're looking at very long term data we have associative data.
159. 8:15People with higher step counts live longer.
160. 8:17People with higher
161. 8:17step counts have lower rates of disease than people with lower step counts.
162. 8:21But it's not the case that the higher step count necessarily causes
163. 8:25the people to live longer.
164. 8:27There's high reverse causality.
165. 8:29Reverse causality means that
166. 8:31the correlation is actually explained by the opposite causation.
167. 8:34So it's people that are less healthy that walk less
168. 8:38because they are very unhealthy, because they have difficulty walking,
169. 8:41especially in elderly individuals
170. 8:42this makes a lot of sense.
171. 8:44Second, there is what's called residual confounding, meaning that other variables
172. 8:48might explain both the effect on step counts and the effect on health.
173. 8:52For example, people that are happier are generally more
174. 8:55physically active, so being happy might cause a higher step count.
175. 8:58And we also know that people that are happier live longer.
176. 9:00So being happy might also cause people to live longer.
177. 9:03And the relation between the step count and health outcome might therefore
178. 9:06be partly an artifact, basically not a real effect.
179. 9:09Last but not least, there are many covariates in this type of association,
180. 9:13meaning there are many other factors that correlate with someone
181. 9:16having a high step count.
182. 9:17People that are more physically active differ
183. 9:19from people that are less physically active in many ways,
184. 9:22and generally these are always that make them healthier to begin with.
185. 9:25Like I said, a high step count is in part a proxy or a measure of someone's
186. 9:30general healthiness.
187. 9:31People that have higher step counts probably also have a healthier diet, for example.
188. 9:35Another very notable finding in health sciences is that effect
189. 9:38of total physical activity and sedentary time are partly independent.
190. 9:43You might think that these are the same things.
191. 9:45Clearly, someone that is more physically active is less sedentary, right?
192. 9:48Well not necessarily.
193. 9:49It's also about how you distribute that physical activity time over time.
194. 9:54So if someone has one long workout
195. 9:56or one long walk, and then the rest of the day
196. 9:58they are completely sedentary, just sitting on their ass in front of computer,
197. 10:01then that might actually not be as healthy as someone that has multiple exercise
198. 10:05snacks, as researchers like to call it these days, throughout the day.
199. 10:08So how you break up the sedentary time might be as important
200. 10:12as the total level of physical activity to begin with.
201. 10:15So what does this all mean in terms of practical application?
202. 10:18This is basically how I explain it to my students and my clients.
203. 10:22There is no doubt that being more physically active is good for you.
204. 10:25The only question is, are the relatively small benefits
205. 10:29worth the time and effort?
206. 10:31For most people, deliberately just trying
207. 10:33to be more active, to lose more fat or to be healthier is not very sustainable
208. 10:37and has relatively marginal benefits, especially compared to putting that energy
209. 10:41into your diet or formal exercise like lifting weights or cardio.
210. 10:45I see some people these days obsessing over their step count, as
211. 10:48if it's some vital target that they have to hit. 10:00 at night, you're wasted,
212. 10:53you want to go to bed,
213. 10:54but you haven't hit your step count, so you have to go for a long walk.
214. 10:57That is not a sustainable lifestyle.
215. 10:59And sustainability is everything when it comes to your lifestyle.
216. 11:02So the real focus should be on sustainability and lowering the cost.
217. 11:06If you can find ways in your life
218. 11:07to be more physically active, but it doesn't cost
219. 11:10you more time and it is not more effortful than those are the ways that I recommend
220. 11:13you try to implement higher physical activity in your lifestyle.
221. 11:17For example, if you can conveniently go to work by bicycle instead of by car,
222. 11:21that is most likely worth it.
223. 11:22If you can work from a standing desk or even better, a treadmill desk,
224. 11:26that is amazing.
225. 11:27That is extremely good.
226. 11:28It doesn't cost you more time.
227. 11:29In research we see that it also does lower productivity,
228. 11:32and you get a significantly higher total daily energy expenditure
229. 11:35and better health benefits.
230. 11:37Same for phone calls and video calls.
231. 11:39If you can do those walking, that is amazing.
232. 11:41Or if there’s, say, an hour long podcast that you listen to every week,
233. 11:44that's a great time to do it while walking.
234. 11:47The key in all of these examples is that they involve a restructuring
235. 11:50of your lifestyle
236. 11:51without a higher total time or effort requirement.
237. 11:54These strategies, in my experience, are far more effective
238. 11:57than tracking your step count and trying to hit 10,000 steps a day.
239. 12:0010k steps a day for
240. 12:01most individuals is above the point that they really need for their health.
241. 12:04The benefits at that point are increasingly diminishing,
242. 12:07and for fat loss
243. 12:08you also run into serious constraint energy expenditure at this point.
244. 12:12Big picture:
245. 12:13The things that really matter for your physique
246. 12:14are your diet and your strength training.
247. 12:16If you get those two right and you do them well,
248. 12:18you have a good training program and you have your diet under control,
249. 12:21the vast majority of my clients have gotten six pack lean
250. 12:24without even monitoring their step count, or even wondering about their
251. 12:28total physical activity level.
252. 12:29Now, if you can increase
253. 12:30your physical activity level in a sustainable way with habits,
254. 12:34routines, and other ways that you can sustainably incorporate it
255. 12:37into your lifestyle without requiring more time or effort, that is great.
256. 12:40Definitely do it.
257. 12:41Beyond strength training and your diet
258. 12:43the next big addition you should be considering is cardio.
259. 12:46Cardio has established health benefits
260. 12:48and can burn a lot of calories in a limited amount of time.
261. 12:51Only after that point, when you've done all of these things,
262. 12:53would I really consider monitoring your step count every day
263. 12:56and making it a point to hit some relatively arbitrary high step count.
264. 13:01I hope this video helps you optimize your lifestyle based on your specific goals.
265. 13:04If you're into evidence based fitness and you want an in-depth review
266. 13:07of all topics fitness, check out my online PT course.
267. 13:11It is the most comprehensive review
268. 13:12of basically all evidence based fitness topics on the market, bar none.
269. 13:16Check it out,
270. 13:17and you can also keep watching this video about constrained energy expenditure.