A 2005 study on KAATSU demonstrated that it’s possible to realize double-digit strength gains using low-intensity resistance training plus KAATSU. This probably doesn’t sound all that impressive. What if I told you that the training period was only two weeks? A little more impressive, eh? Here’s what they did.
Twice a Day for 12 Days
If you’ve worked out, you’ll know that most of the time you don’t do two “leg days” in a row. In a typical strength training scenario you’re lifting weights that are 80% of your 1-rep maximum. 3 sets of 12~15 reps is usually enough to get your muscles to feel the burn, and then you need a couple of days to recover. KAATSU is not typical.
In this study, participants had their 1RM evaluated in the squat and leg curl. They then participated in two weeks of supervised daily resistance training with one session in the morning and the other in the afternoon. One group of participants lifted with 20% of 1RM plus KAATSU for 3 sets of 15 reps, while another group did the same activity without KAATSU. Participants did two workouts a day for 12 days straight (excluding one Sunday).
Double-Digit Strength Increases
After 2 weeks, the KAATSU group saw an absolute squat strength increase of 16.8% and leg curl strength increase of 22.6%. The non-KAATSU group also saw increases of 8.9% in the squat and 1.3% in the leg curl. Mid-thigh muscle-bone cross-sectional area (CSA) increased by 8.5% in the KAATSU group and 1.8% in the non-KAATSU group. Glute muscle volume increased 9.1% in the KAATSU group but decreased 0.6% in the non-KAATSU group.
KAATSU vs Non-KAATSU Results:
- Squat Strength: +16.8% vs +8.9%
- Leg Curl Strength: +22.6% vs +1.3%
- Muscle CSA: +8.5% vs +1.8%
- Glute volume: +9.1% vs -0.6%
How is this possible?
Here are some proposed explanations discussed in the study.
- Levels of circulating Growth Hormone (GH) 15-minutes post KAATSU exercise has been shown to be 3x larger than increase in GH following high-intensity exercise. Increased levels of GH lead to elevated levels of circulating IGF-1 which stimulates muscle protein synthesis. Increased levels of IGF-1 may have contributed to the strength gains and muscle hypertrophy observed in this study.
- Light weights plus KAATSU triggers the anabolic cascade responsible for muscle growth while minimizing the microscopic muscle damage typically experienced when lifting with higher weights. This allows a shorter recovery period between training sessions. This study had participants do 24 sessions in 12 days. Typical resistance training studies have people exercise 2~3 times per week at most.
So there you have it. Increased training frequency with less muscle damage using lower weights and KAATSU can create significant strength gains in a relatively short period of time. Knowing this is possible, how might that affect your own workout routines?
Disclaimer: KAATSU protocols have not been evaluated by Health Canada. KAATSU is not intended to diagnose, treat, cure, or prevent any disease and its use should be evaluated by your own physician before use.