- Twenty-five resistance trained men were randomly assigned to either a deadlift group or a squat group.
- Both groups trained three times per week for six weeks.
- The squat group increased their squat 1RM by 13.3% and their deadlift 1RM by 6.7%. The deadlift group increased their squat 1RM by 4.7% and their deadlift 1RM by 17.7%.
How much does the squat carryover to the deadlift? And how much does the deadlift carryover to the squat?
The squat and the deadlift work similar muscles, albeit with some differences. Both exercises require strong hip extending muscles such as your glutes and adductors, but in comparison, the squat requires stronger quads and the deadlift requires a stronger back.
Here’s how we’ve assigned primary and secondary worked muscles for each exercise in our workout tracker, based on scientific evidence.
Because of this overlap, it is reasonable to assume that if you get a lot stronger in the squat, you’d also increase your strength in the deadlift, and vice versa.
But how much stronger?
A new study provides us with some raw numbers.1
Squat or Deadlift Training for Six Weeks
Twenty-five resistance-trained young men were randomly assigned to either a deadlift group or a squat group. They were in their early twenties and had a mean body weight of about 84 kg.
The men had at least three years of resistance training experience, and a mean squat 1RM of ~140 kg, and a mean deadlift 1RM of ~135 kg.
Typically, we are capable of lifting more weight in the deadlift than in the squat which makes these mean 1RMs a bit odd, but it is plausible that these participants simply had much more experience squatting than they did deadlifting.
Another thing I want to point out is that there was quite a strength difference between the two groups at the onset of the study, at least in the squat. Starting out, the deadlift group had a 23% higher 1RM in the squat (152.7 vs. 124.0 kg) and a 9% higher 1RM in the deadlift (141.4 vs. 129.1 kg). This might influence the results, and I’ll get back to that later.
The Training Program
In addition to doing either squats or deadlifts three times per week, the participants also trained countermovement jumps (CMJ) and some upper body exercises every workout. One of the workouts also included a few leg curls.
Here’s how their weekly training program looked.
|Squat OR Deadlift||Squat OR Deadlift||Squat OR Deadlift|
|Barbell Row||Bench Press||Incline Bench Press|
|Lat Pulldown||Overhead Press||Upright Row|
|Barbell Curl||Lateral Raise||French Press|
The training volume was high: every exercise was performed for five sets per workout except the sixth week when they did four sets of each. They started at 10 reps in each set and gradually moved down to 4 reps over the weeks as the weights got heavier.
Perhaps non-surprisingly, three out of fourteen participants in the deadlift group withdrew due to lower back pain. Judging by their relatively low starting 1RM in the deadlift, perhaps they weren’t used to doing 15 working sets of deadlifts per week, and the increase in volume was too steep.
Before and after the six weeks of training, the participant’s 1RM in the squat and deadlift was tested.
Results: Specific Gains with Carryover
Here’s how the participant’s 1RMs changed from pre to post-training.
- Squat 1RM: 124.0 kg to 140.5 kg (+13.3%)
- Deadlift 1RM: 129.1 to 137.7 kg (+6.7%)
- Squat 1RM: 152.7 to 160.0 kg (+4.7%)
- Deadlift 1RM: 141.4 to 166.4 kg (+17.7%)
As for CMJ power, it increased by 2.7% in the squat group and 1.9% in the deadlift group.
Based on skinfold measurements and weighing, both groups increased their fat-free mass by about a kilo without gaining any fat.
Note that there are some inconsistencies between what the authors write in their article and what is reported in the results tables. In these cases, I’ve chosen to go by what is presented in the tables.
So each respective group improved their 1RM mostly in the lift they trained the most (13.3 and 17.7% for the squat and deadlift group, respectively), and to a smaller extent in the lift they didn’t train (6.7 and 4.7% for the squat and deadlift group, respectively), which is right in line with the principle of specificity.
So did training one lift help the other? Maybe. This study is a case in which a non-training control group that only performed the 1RM tests would have been valuable. Simply performing 1RM tests can improve your performance in them, and it would have been interesting to see how big a difference these two groups would have had compared to a control group. It would also be interesting to see a group training both the squat and the deadlift, splitting the training volume evenly between them.
Secondly, the deadlift group was 23% stronger in the squat and 9% stronger in the deadlift before the training protocol. Because of the ceiling-effect in strength, a stronger group might see smaller strength gains compared to a weaker group.
Still, if we take these results for what they are, it seems that training only the squat or deadlift (plus some exercises for the rest of your body) might just help to increase the other lift as well.
If we take the results from this study at face value, the main takeaway is two-fold:
- Train the lift you want to improve in. The principle of specificity reigns supreme in sports. The participants saw the biggest gains in the lift they practiced: 13.3 and 17.7% for the squat and deadlift group, respectively.
- Some carryover between lifts. The participants still saw some improvements in the other lift despite not training it for six weeks: 6.7 and 4.7 % for the squat and deadlift group, respectively.
It would have been interesting to see what would have happened if we had a third group that split their volume between both lifts. It’s possible that the squat and deadlift are great complementary exercises for each other, and that having both in your training program creates a nice symbiosis.