I'm able to dead lift 270 at 5 reps without straps, after that I need to add straps to get to 400. How much more should I be able to hold if I used chalk?
My anecdotal findings are that I can lift between 15-20% more with a chalked mixed grip than I can by using a non-chalked mixed grip. My n=1 study occurred this past week when I forgot to pack my chalk:
- No chalk, 405 lb deadlift: 2 reps, missed lockout, dropped weight @ 9 RPE, next week;
- Chalk, 405 lb deadlift: 5 reps, continuous @ 7 RPE.
Using the handy RPE calculator and looking at the comparative 1RMs, 405x5@7 divided by 405x2@9 is about 17% more in terms of a 1RM.
Week to week isn't a great comparison but the takeaway here is that you really should use chalk if you're lifting heavy. In addition to being able to move more weight, the chalked deadlift is consistent. To me, this means that chalk removes my grip as the limiting factor and can allow me to work on my legs and back, as it should be. Some days are sweatier than others but chalking lets you avoid that.
There are a few rock climbing studies that have looked at the effectiveness of chalk. This study found that participants were able to complete 16% more open-handed pull-ups when using chalk and 58% more pinch-grip pull-ups when using chalk:
(mean [chalk] = 22.8 ± 4.53 vs. mean no chalk = 19.7 ± 4.39 reps; p = 0.006)
(mean [chalk] = 14.4 ± 4.47 vs. mean no chalk = 9.1 ± 4.83 reps; p = 0.007)
Another rock climbing study found that participates could hang on for 29% longer when using chalk:
[chalk hang =] 62.9 ± 36.7 s and [non-chalk hang =] 49.3 ± 25.2 s (P = .046)