Tag Archives: sport

Recovering faster from a sprint by jogging than by walking

It seems that the panting and muscle weakness right after a sprint passes faster when I jog than when I walk or stand (the recovery I am talking about here is the minutes it takes to get back to normal breathing, not the days it takes for muscle soreness to disappear). I did not find empirical research on whether jogging actually speeds recovery from a sprint – it could be just my false perception. For this blog post, I will assume my perception is correct and speculate about why.
Faster recovery of breath when jogging seems counterintuitive, because jogging takes more power (energy per unit of time) than walking, so consumes the body’s cardiovascular output and nutrient reserves faster. The increased consumption should delay the short-term recovery. However, the perception of recovery need not be positively correlated with the whole body’s oxygen and glucose consumption, only with the CO2 reaching the chemoreceptors (either central in the brain’s respiratory centre, or peripheral in the carotid arteries and the aorta).
If the blood vessels in the legs expand during a sprint, and the blood pressure falls after a sprint faster than the blood vessels contract, then blood may pool in the legs and less of it may reach the chemoreceptors. Blood is forced up from the legs by the contractions of the leg muscles, which are more intense and frequent during jogging than walking. Therefore jogging may increase the venous return, leading to a better blood supply to the torso and the brain, which the latter perceives as faster recovery from exercise.
Even if the contractions of the leg muscles during jogging and walking had the same intensity and frequency, the group of muscles activated during jogging does not completely overlap with those working during walking. One muscle group may surround the major veins in the legs more closely, thus pump blood up more effectively.
There may be evolutionary reasons why the jogging muscles are better at stimulating venous return – faster overall circulation is needed during more intense exercise, for example when jogging compared to walking. Better venous return speeds up the circulation.
A mechanical reason why jogging may improve recovery from a sprint better than walking is that the jogging muscles overlap with the sprinting muscles more than the walking muscles do. If blood pools in the sprinting muscles and needs to be returned to the core, then contracting the jogging muscles forces blood out of the sprinting muscles better than contracting the walking muscles does.

Rigid skirt to prevent falls

Falls are a major cause of hospitalisation in the elderly and people with impaired balance or strength. A fall may cause a vicious cycle: the bad experience leads to a fear of falling, which makes people avoid exercise. Not exercising leads to worse balance and muscle condition. Weakness and a lack of balance cause more falls.
To prevent falls, people should train their sense of balance and their stabilising muscles, but in a way that does not risk injury via falls during training. One device that would allow practising balance while preventing falling over is a rigid wide-flared skirt attached above a person’s centre of gravity (the attachment could be almost under the armpits). The hem of the skirt would be above the ground when the body is upright, but its edge would touch the ground if the body tilts too much in any direction. Support from the rigid skirt would then prevent further tipping in that direction. The lack of support in a central position (and for slight tilts around it) allows practising balance, for example by standing on one leg and trying to stay upright. The principle is the same as for helper wheels (training wheels) on childrens’ bicycles, which are off the ground while the bike is in a central position, but touch the road and stop too great a tilt to the side once the bike tips away from the centre. Other analogies to the rigid skirt are hands-free crutches pointing in all directions simultaneously, or a walking frame that surrounds the body, as opposed to being pushed in front.
The advantage of the skirt for fall prevention over crutches or a walking frame is that the skirt is hands-free. The advantage over a fixed training frame, or somewhat slack ropes tied to the upper body that also prevent a fall, is that the skirt moves with the person. This makes training easier by allowing walking and jogging.
The skirt can be home-made from many materials, such as tent poles or bamboo sticks tied or duct taped to a belt at the top and a hula hoop at the bottom. Using modern materials such as carbon fiber ski poles can make the skirt light, yet strong and rigid.
Of course the rigid skirt looks strange and attracts notice if not too many people are using it. On the one hand, the skirt does not have to be used in public if in-home training is enough. On the other hand, the first walking frame or the first crutches must also have looked strange to bystanders, but are now accepted mobility aids that almost nobody reacts negatively or even curiously to.
For using the skirt on the street, one problem is the wide-flared base (about 2m in diameter) that makes it difficult to pass other pedestrians. One (expensive) solution is to make the skirt out of sticks that can be moved independently and add a robotic controller that keeps the skirt narrow if the body is upright, but when the tilt angle becomes large enough, flares the skirt out in the direction of the tilt to stop the fall. Flaring the skirt means moving the sticks outward and lengthening them.

Bodyweight exercise list

Plank Ups: Start in high plank. Bend one arm to bring your elbow and your forearm to the floor. Bring the other arm down so you are in a forearm plank. Push back up to the start position, placing each hand where your elbows were.
Plank Taps: Start in high plank with your feet hip-distance apart. Then tap your left hand to your right shoulder while engaging your core and glutes to keep your hips as still as possible.
Lateral Plank Walks: Start in high plank. Step your right foot and your right hand to right side immediately following with your left foot and your left hand.
Plank Star Jumps: Start in high plank. Keeping your core engaged, jump your feet out wide and back in (like star jumps).
Plank with lifting right arm and left leg, then lifting left arm and right leg.
Plank with arm lifts to the side (90 degrees with the body) without turning torso.
Plank high knee run: in plank, alternately bring one knee to chest, then the other.
Plank knee to same shoulder: in plank, alternately bring left knee to left shoulder, return to plank, bring right knee to right shoulder.
Crocodile walk: from plank, step left foot close to left hand, left knee is close to left shoulder. Step right hand forward. Then step left hand and right foot forward, so the right knee is close to right shoulder. Repeat with right hand and left knee. Stay low, with bent elbows and one knee bent.
Plank knee to opposite elbow or shoulder: in plank, alternately bring one knee under the body to the opposite armpit, return to start, then the other knee to the opposite armpit. Intensification: straighten the leg that crosses under the body, without touching the leg to the ground.
Plank or tabletop side leg lifts: similar to plank knee to shoulder, but straight leg lifted to the side.
Bear pose: from tabletop pose (hands and knees on the ground), lift knees slightly off the ground, so you are standing on hands and toes, with hips and knees bent at 90 degrees.
Crunches: lying on your back, knees and hips bent, feet on the ground, lift torso toward knees, return.
Leg lifts on your back: lying on your back, lift both straight legs without arching the back (lower back stays on the ground). Then lower the legs back down. Repeat.
Supine leg rotations: lying on your back, lift straight legs 30 degrees off the ground, make circles with the legs, keeping the legs together and straight. Lower back stays on the ground, no arching of the back.
Jackknife: lying on your back, arms overhead, bend at the hips to lift both straight arms and straight legs, touch fingers to toes.
Windshield wiper: lying on your back, hips bent 90 degrees, feet touching, keep both shoulders on the ground and rotate from the waist to move both feet to one side to touch the ground, then lift back up. Repeat on the other side.

Push-Ups or clapping push-ups.
One-arm push-ups.
Handstand push-ups.
Push-up into side plank, then back to push-up, then side plank on the other side.
Staggered push-ups: push-ups with one arm placed more forward than the other.
Burpees/ squat thrusts: do a push-up, then jump legs close to hands, then jump up, return to low squat, put hands on the floor, jump legs back to plank. Repeat.

Calf raises: Stand on one leg, rise up on your toes, return down.

Low plank or chaturanga leg lifts. Start with hands (or elbows) and feet on the ground, body straight, elbows bent 90 degrees. Lift one leg toward the sky. The leg may be straight or bent. Do not rotate the foot outward, but keep pointing the toes in and up. Keep abdomen tense to lessen the use of the back muscles, focus on lifting with the hamstring instead.
Isometric heel press: stand on one foot, bend the other knee 90 degrees and press the heel up against the hand, keeping the hips straight. Tense the abdominals to discourage using the lower back muscles. Use the hamstring instead.

Quads, glutes, sides of hips
Squats or squat jumps, or one-legged squats.
Forward-backward squat jumps: from a squat, jump forward into a squat, then back to starting position.
Wide-legged squats or wide-legged squat jumps.
Lunges, perhaps adding a front kick after standing up from each lunge.
Lunge jumps: start on left foot and right toes, with the left hip, knee and ankle bent 90 degrees, the right hip straight and the right knee and ankle bent 90 degrees. Jump into the same position on the opposite side: right hip, knee and ankle bent 90 degrees, left hip straight, the left knee and ankle bent 90 degrees.
Lateral lunges: from standing, step wide to the left, bending the left knee, keeping the right leg straight. Step back to standing. May add a leg raise to the side after each lunge.
Curtsy Lunges: from standing, cross one leg in front of the other and do a squat.

Superman: lying on your belly, straight arms pointing above head, lift both arms and straight legs. Keep the legs together.
Locust: lying on your belly, straight arms behind back, fingers interlocked, lift torso and straight legs.
Airplane: lying on your belly, straight arms in a T position to body, lift both arms and both legs. Keep the legs together and straight.
Prone snow angel: lying on your stomach, lift both arms, move straight arms from pointing toward feet to pointing above head, then back toward feet (from locust to airplane to superman pose, then back to airplane and to locust).
Forward bend/ good morning: from standing, bend forward at the hips with a straight back and straight legs, fingers interlocked behind the head. Then stand tall again. Intensification: keep straight arms overhead (in one line with the back) the whole time.
Bridge/ hip raise, or one-legged bridge. In one-legged bridge, the other leg can be straight or bent, parallel to ground or pointing to the sky.
Upward plank: facing the sky, support your weight on hands and heels. Keep arms, legs and body straight, with legs and body forming one line.
Upward plank leg raises: from upward plank, raise one leg from the hip, keeping the knee straight. The other leg and the body still form a straight line.
Ant walk/ crab walk: facing the sky, walk on your hands and feet, knees bent about 90 degrees, elbows almost straight. Keep your hips and back straight.

Obliques/side muscles
Side bend: stand straight, arms straight overhead, elbows straight, fingers interlocked, biceps squeezing the ears. Bend to one side, then stand tall again. To focus on the side muscles, not lower back or abdomen, bend exactly to the side, not forward or back.
Side Plank. Intensification: lift upper leg, perhaps grab toe of upper leg.

Dive bomber/ Hindu push-up/ Downdog-to-chaturanga and return to downdog. Start with hands and toes on the ground, hips bent 90 degrees, legs and arms straight, arms in one line with the back. Bend elbows and move chest between hands until the hips are straight (body and legs form one line) and chest hovers a few cm above ground. Then return to start.
Downdog push-ups/ inverted shoulder press/ pike press. Start with hands and toes on the ground, hips bent 90 degrees, legs and arms straight, arms in one line with the back. Bend elbows so head approaches floor between the hands. Keep hips at 90 degrees, back and neck in one line. Push back to starting position.
Arm circles: standing, straight arms in T position (straight line through both arms), make as small and fast circles with the arms as possible.

Narrow push-up: hands close to each other on the ground, elbows brushing sides of torso.
Diamond Push-Up: thumbs and forefingers form a triangle.
Triceps Dip, or one-arm triceps dip: Sit on the ground with your legs in front and your back close to a chair, box or step. Place your palms on the box behind you, fingers facing toward your body. Straighten your arms to lift your legs and butt off the ground, then bend your elbows to lower back down (without letting your butt touch the ground). Keep your heels on the ground, elbows directly behind your body.
Reverse push-up: face the sky, hands and heels on the ground, body and legs in one straight line. Bend the elbows, then push back up until the elbows are straight again. Keep the body and legs straight while doing this.
Back-to-wall push-aways: stand with your back against a wall, feet away from the wall, body and legs in one straight line. Push away from the wall using your elbows or hands.

Knee lift run on the spot.
Butt kick run, hips straight.
Forward kicks/ can-can, or forward kicks with jumps.
Scissor stepping to the side: from standing, cross left leg in front of the right, then step right leg to the right so the legs are not crossed any more. Then cross the left leg behind the right, then step the right leg to the right. Repeat. Then switch sides.
Forward sprint.
Backward run.
Gallop to the side: one leg steps wide to the side, then the other hops to meet it. Repeat. Then switch sides
Hop on one foot, forward and backward.

The motivation for this list was my inability to find a good ad-free list of bodyweight exercises online. By bodyweight I mean exercises that do not require rubber bands, a chin-up bar, weights or other equipment. Preferably the exercises would only require a floor, not even a wall or a chair, but I included some exercises above that do require these.