Box jumps. Another body weight exercise that really tests you cardiovascular system but also the strength of your Achilles tendons. If you aren't careful, you will rupture an Achilles tendon - something NO ONE wants.
If you take heed of these tips, you can avoid injury and still maintain a good rate of reps.
1. Consider stepping down or non-rebounding box jumps
If you have not done many rebounding box jumps before, NOW IS NOT THE TIME TO START!!If you have not trained for rebounding box jumps, then stick to regular box jumps or step downs...your body will thank you!
A rebounding box jump is where you jump up to the box, stand up as per the standards, drop down and rebound back to the top. It is an advanced move and should only be done under the careful supervision of your coach. I would also recommend that you start from a manageable height like a few plates and slowly build up from there.
My main concern is that your Achilles tendon, like other tendons and ligaments, develop much more slowly compared to your muscles...some suggest up to x10 slower. For beginners, that means it can take a year or more for your tendons and ligaments to catch up to the strength gains that you have made (that also goes for kipping pullups, ring dips and muscle ups).
If you are a top level athlete gunning for the top of the leaderboard and making regionals or masters, then you will probably need to do rebounding box jumps. If this is the case, you can't have any niggles in those calves. Blowing an Achilles usually comes without warning...be safe and fight for more reps in other workouts.
2. When you land on top of the box, land as high as possible.
This is another of those obvious but needs-to-be-stated pieces of advice. The higher you can jump, the less distance you have to stand up.
If you are vertical-leap-challenged like me, then just aim to get safely on the box. I won't be breaking any speed records 😉
3. When you jump up, land with your back straight like catching a clean.
If you can adopt positions similar to your strength positions, your body will behave more efficiently. Less flexion in your back will lead to less fatigue in your back and more power to your legs. If your back is not worn out by repetitive flexion, you will be in a better position to complete the rest of the work.
4. When you drop down, follow these 2 tips...
- Decrease the distance by dipping or 1/4 or 1/2 squatting first. This decreases the distance you will have to drop from and your calves and Achilles tendons will thank you. Done right, it is quite quick. Annie Thorisdottir did a slight dip compared to Lindsey Valenzuela - see here - the event starts 20mins in...
- When you land, land like midfoot running and absorb the shock with a straight back. Then you can load efficiently and jump back to the box without straining your back muscles
5. Practice with the most stringent standards
Ben Gerard is an Australian CrossFit athlete who did well on the 13.2 Open workout. Unfortunately, it was deemed that he did not meet the movement standards and his quest for a Regionals spot ended on that 2nd workout. Ben has a lot of heart and will NOT make the same mistake twice...but learn from his error.
Find a friend who is not scared to no-rep you and will enforce the correct standards. Make sure you stand up at the top of the box. Practicing this now and getting faster with this standard will mean you can just focus on getting the work done. If doing the reps properly in practice feels weird now, what makes you think it will be better when you are being judged?
Please take care. Rebounding box jumps are for high level athletes. Tendons take time to develop strength!