Lacrosse workouts: strength, speed, protective kit and concussion

Two games under one name

Men's and boys' lacrosse allows body checking, with helmets, gloves and pads. Women's and girls' lacrosse doesn't, and limits stick checks, with eyewear and a mouthguard.

Sources 1, 2, 3, 4

Concussion is the commonest high-school diagnosis

In US high schools, boys' concussions came mostly from contact with other players, and girls' mostly from sticks and balls.

Sources 5, 6, 7

Eyewear protects eyes

After eyewear became compulsory in US girls' lacrosse, eye injuries fell by over 80% with no rise in total injuries. England Lacrosse makes eyewear compulsory from 1 September 2026 wherever a hard ball is used and a helmet with a face mask isn't required.

Sources 8, 9

A ball to the chest can stop the heart

Lacrosse is the second commonest US sport for commotio cordis, a cardiac arrest from a blow to the chest. Survival was 40% when resuscitation started within 3 minutes, against 5% later, so CPR and a defibrillator at the field matter.

Sources 10, 11

Knees, ankles and hamstrings

Ankle sprains, knee injuries and hamstring strains are common. No prevention programme has been tested in lacrosse, but warm-ups with strength and landing work halve knee ligament injuries in other sports, and Nordic hamstring programmes go with fewer hamstring injuries.

Sources 12, 13, 14, 15

Build conditioning gradually

In 2024-25, 9 US college lacrosse players were admitted to hospital with serious muscle breakdown (rhabdomyolysis) after a single conditioning session.

Source 16

Sprints, cuts and contact

In 18 US college women, players covered 4,733 m a game on average, with 124 sprints, 51 hard accelerations and a top speed of 24.1 km/h. Austrian international women covered 3,792 m at an average 75% of maximum heart rate. The Compendium of Physical Activities gives lacrosse 8.0 metabolic equivalents (METs), an estimated value.

Sources 17, 18, 19

By position and gameEmerging evidence

Midfielders ran the most at high speed in Japanese and Australian players, and most measures fell by the fourth quarter. US college men ran more in games than in practice; women's teams covered more distance and sprints, men's more accelerations and decelerations; and women's lacrosse and field hockey were more intense than soccer. These are small studies using GPS trackers.

Sources 20, 21, 22, 23, 24

ShootingEmerging evidence

In 20 players, shot speed went with how far they could throw a medicine ball, and less closely with jump height and grip strength. Players with low back pain turned their hips, trunk and shoulders less when shooting, and those who developed back pain over 6 months had faster pelvic movement. These are associations.

Sources 25, 26, 27

Landing and cuttingEmerging evidence

In 31 US college women, lacrosse players landed with less knee bend than field hockey players, a pattern linked with knee ligament injury. This is a laboratory study.

Source 28

Where the load falls

The sites the studies point to:

• Knees and ankles: cutting and landing.
• Hamstrings: sprinting.
• The head, face, hands and chest: sticks, balls and, in the men's game, body checks.
• The low back: twisting to shoot.

Sources 29, 12, 13, 30, 7, 26

What to train (our reading)

Repeated sprints and short accelerations, leg strength and landing control for the knees, hamstring and groin strength, ankle balance, and rotation through the hips and trunk for shooting. Players in contact games add upper-body and neck strength.

How often players get hurtEmerging evidence

The numbers, by group:

• US college men and women, 2014 to 2019: 4.90 and 4.99 injuries per 1,000 athlete-exposures (one player in one game or practice).
• US high schools, 2008 to 2012: 1.96 per 1,000 athlete-exposures (boys 2.26, girls 1.54), with 3.61 in competition against 1.23 in practice.
• US youth boys, 2014 to 2017: 10.3 per 1,000 athlete-exposures counting every injury, but 2.0 counting only injuries that stopped play for a day or more.
• US youth players, 2015 to 2016: boys 12.7 and girls 8.7 injuries per 1,000 games or practices.
• Boys' summer club tournaments, 2018: 2.13 per 1,000 athlete-exposures.
• Japanese college players: 42% injured in a year.

Sources 12, 13, 31, 32, 33, 34, 35

ConcussionEmerging evidence

Concussion was the commonest diagnosis in US high-school lacrosse, and boys' lacrosse had the third-highest concussion rate of 20 high-school sports, after American football and boys' ice hockey. Boys' concussions mostly came from player contact (66%), girls' from sticks and balls (73%), and women had over 3 times men's risk of concussion from a ball or stick. Youth boys had more than twice the concussion rate of high-school players. Our concussion guide covers the graduated return.

Sources 5, 6, 36, 7, 37, 32

Heads, faces and eyesEmerging evidence

Head, face and eye injuries were more common in girls and women than in boys and men: 0.54 against 0.38 per 1,000 athlete-exposures in high school, and 0.77 against 0.44 in college. In US college women's games, 22% of injuries were to the head and neck, 56% of those from a stick; in youth girls, 75% of head and face injuries came from the ball.

Sources 38, 39, 33

KneesEmerging evidence

In US college players, anterior cruciate ligament (ACL) injuries ran at 0.17 (men) and 0.18 (women) per 1,000 athlete-exposures, similar in both games, unlike basketball and soccer where women's rates are higher. Lacrosse is among the higher-risk sports for teenagers. In one women's college team, ACL injury was 5 times as likely in the year after a concussion, a small study. Our ACL injury, medial collateral ligament (MCL) sprain and meniscus tear guides cover these.

Sources 40, 41, 42, 43

Ankles and hamstringsEmerging evidence

Ankle sprains were the commonest injury in US college women (9.1%) and second in men (7.7%), and hamstring tears were 6.9% of men's and 3.8% of women's injuries. Across studies, the lower leg, ankle and foot were the most injured region. Our sprained ankle and hamstring strain guides cover treatment.

Sources 12, 13, 44

HandsEmerging evidence

In one review, hand injuries were 23% of men's injuries, 59% of them to the thumb, and youth injuries came mostly from stick contact. Our broken finger, broken hand and skier's thumb guides cover these.

Sources 30, 32

Catastrophic events and collapseEmerging evidence

From 1982 to 2020, US lacrosse had 69 catastrophic events at youth, high-school and college level, 36% of them fatal. Fifteen were commotio cordis and 15 were cardiac arrests from heart conditions, and deaths from these two fell by 95% from 1982 to 2007 compared with 2007 to 2020. In 2024-25, 9 college players were admitted to hospital with rhabdomyolysis after one conditioning session.

Sources 45, 16

Low back painEmerging evidence

Back pain went with how players rotated when shooting, in 128 players followed for 6 months. Our back pain guide covers what to do.

Sources 26, 27

Who's at higher riskEmerging evidence

Games more than practice; the preseason; boys from player contact and girls from sticks and balls; young players still learning stick skills; college more than high-school players for catastrophic events; and, in single studies, a recent concussion for knee injury and cleats with conical studs, rather than turf shoes, for ACL tears in girls and women. These are associations.

Sources 31, 46, 7, 32, 45, 43, 47

The eyewear mandateEmerging evidence

After US Lacrosse made eyewear compulsory in girls' and women's lacrosse in 2004-05, eye injuries in high-school girls in one county fell from 0.10 to 0.016 per 1,000 athlete-exposures, and other head and face injuries fell too, with no rise in total injuries. Recorded concussions rose, which the authors put down mainly to better recognition. In an earlier New York study, goggle wearers had 16.5% fewer head and face injuries, and 51% fewer in games.

Sources 8, 48

Checking rulesEmerging evidence

After US high schools brought in heavier penalties for hits to the head or neck (2012-13) and banned body checks on players in a defenceless position (2013-14), concussions from delivering body checks fell by about half. Checking-related head and neck injuries fell in practice, but not in games. USA Lacrosse doesn't allow body checking in youth play until 14U (under-14).

Sources 49, 1

The FIFA 11+ in US high schoolsEmerging evidence

In 14 US high schools randomised to run the FIFA 11+ (the warm-up from football's world governing body) or their usual warm-up, across football, soccer, basketball and lacrosse, lower-limb injuries didn't differ (1.59 against 1.47 per 1,000 athlete-exposures). Only 32% of coaches ran the full programme twice a week, and observers saw it done completely in 28% of warm-ups. In football, done regularly, the 11+ cut injuries by 39%.

Sources 50, 51, 52

ACL programmes, borrowed from other sportsStrong evidence

Across 8 meta-analyses, warm-ups with strength, jump-and-land and balance work halved ACL injuries and cut ACL tears without contact by about two-thirds in women and girls. Women in team sports tear an ACL about twice as often as men. None of these programmes has been tested in lacrosse.

Sources 14, 53

Nordic and Copenhagen programmes, borrowed from footballEmerging evidence

Programmes including the Nordic hamstring exercise were linked with about half as many hamstring injuries across sports, though when only properly randomised trials are pooled the effect is uncertain. The Copenhagen adductor exercise cut groin problems by 41% in semi-professional footballers. Neither has been tested in lacrosse.

Sources 15, 54, 55, 56

Ankle braces and balance, borrowed from other sportsStrong evidence

Lace-up ankle braces cut ankle injuries by about two-thirds in high-school basketball players, and across trials braces cut repeat sprains by about two-thirds and first ones by about half.

Sources 57, 58

MouthguardsEmerging evidence

USA Lacrosse requires a mouthpiece in both games. Across sports, people without mouthguards had over twice the risk of mouth and face injuries, and in collision sports mouthguards went with about a quarter fewer concussions.

Sources 1, 2, 59, 60

Conditioning safelyEmerging evidence

The US catastrophic injury registry recorded a cluster of 9 college lacrosse players admitted to hospital with rhabdomyolysis after one conditioning session in 2024-25, and names heat, dehydration, baseline fitness and sickle cell trait as risk factors. Our rhabdomyolysis guide: build new training up over weeks, treat the first 7 to 10 days back as a gentle lead-in, and never use exercise as a punishment.

Source 16

What isn't shownMixed evidence

No prevention programme has been tested on lacrosse injuries, and most lacrosse research comes from US college players. Hard helmets for girls have been modelled, not tested. Neck strength had only small links with concussion across team sports.

Sources 61, 7, 62

Sprint intervals, as trialled in high-school girlsEmerging evidence

Twelve 16-year-old girls added 3 sprint sessions a week for 12 weeks to their lacrosse training:

• Session 1: 10 to 14 all-out 40 m sprints, walking or jogging 15 to 20 seconds between them.
• Session 2: 2 to 3 sets of 10 to 12 all-out 15 m sprints, 15 seconds between sprints and 2 minutes between sets.
• Session 3: 3 to 4 shuttle runs ("suicides") of 16, 25, 50 and 75 m, with 60 seconds between them.
• Result: how fast the thigh muscles produced force rose by 42% by mid-season, and maximal strength by 20%. There was no comparison group.

Source 63

PowerEmerging evidence

In 15 college men, jump shrugs did more work at the hip and knee than hang power cleans and peaked at lighter loads (30 to 50% of the most they could lift, against 70%). Shot speed went with medicine-ball throwing distance, jump height and grip strength.

Sources 64, 25

Movement skill in young playersEmerging evidence

In 134 teenage boys, how well they performed basic lifts went with their power, and more mature boys were more skilled, an association. Learning to lift well comes before loading up (our reading).

Source 65

Training by position

Midfielders run the most at high speed; attackers and defenders make many short accelerations and stops; the women's game covers more distance and the men's more accelerations. Our suggestion: repeated sprints for midfielders, and short acceleration and deceleration work for everyone.

Sources 17, 20, 21, 23

Fitting it around lacrosse

Off-season: 2 or 3 strength and power sessions a week, with sprint work twice a week. Preseason: sprint intervals up to 3 times a week as in the girls' study, counting practice running as part of the load, and the Nordic and Copenhagen programmes on their football schedules. College injuries peak in the preseason, so build up gradually, with a gentle first 7 to 10 days back.

In season: 1 or 2 shorter strength sessions, with no heavy legs, Nordic lowers or hard jumping in the 48 hours before a game (our suggestion).

Sources 63, 46, 16

USA Lacrosse youth rules for boys, 2026Strong evidence

Body checking is illegal at 10U and 12U (under-10 and under-12), though some body contact is allowed, and legal at 14U, from the front or side between the shoulders and waist, without "take-out" checks. Targeting the head or neck is an automatic ejection. Required kit: a helmet meeting the standard of the National Operating Committee on Standards for Athletic Equipment (NOCSAE), a mouthpiece, gloves, arm pads, a cup, and shoulder pads meeting NOCSAE's ND200 standard; goalkeepers add a throat protector and an ND200 chest protector.

Sources 1, 66

USA Lacrosse youth rules for girls, 2026Strong evidence

No checking at 10U and younger, modified checking at 12U and transitional at 14U, with stick checks kept outside a 12-inch sphere round the head (7 inches in high school). Field players wear eyewear meeting the ASTM F3077 standard and a mouthpiece; soft headgear meeting ASTM F3137 is optional, and face masks aren't allowed. Goalkeepers wear a helmet, a throat protector and, since 1 January 2021, an ND200 chest protector.

Sources 2, 67

World LacrosseStrong evidence

The 2025-26 women's field rules require a mouthguard, make eye guards optional and don't allow headgear for field players; the 2025 to 2027 men's rules require gloves, a helmet with a face mask and chinstrap, and a mouthguard. On 12 May 2026, World Lacrosse adopted new standards for its events: eyewear for all women's field and women's Sixes players, soft headgear permitted, NOCSAE helmets, goalkeeper chest protection, and shoulder pads meeting the commotio cordis standard in men's field, men's Sixes and men's and women's box lacrosse. They phase in from the 2027 Sixes, 2028 box and 2029 under-20 field championships. World Lacrosse doesn't require chest protection for women's field players: "Current research indicates that women are not at the same risk as men".

Sources 3, 4, 68, 69

England LacrosseStrong evidence

From 1 September 2026 (announced 14 August 2026): "Protective eyewear will be mandatory for participants taking part in all organised lacrosse activity in England where a non-deformable lacrosse ball is used and the playing rules do not already require a protective helmet with a face mask." Eyewear must meet ASTM F3077 or carry a UKCA mark, "No exemptions are permitted", soft headgear is optional under non-contact rules, and soft balls are exempt. England's mixed lacrosse is non-contact and requires a mouthguard, and hard helmets aren't allowed for its field players.

Sources 9, 70, 71, 72

Eyewear: fewer eye injuries, no change in concussionsEmerging evidence

After the 2004-05 US mandate, eye injuries in high-school girls fell from 0.10 to 0.016 per 1,000 athlete-exposures. Pooled across studies of women and girls, eyewear made no difference to concussion either way, very low-certainty evidence.

Sources 8, 48, 73

Soft headgear: the evidence points both waysMixed evidence

In Florida, which made soft headgear compulsory in high-school girls' lacrosse, concussions ran at 0.27 per 1,000 athlete-exposures against 0.44 in 31 states without the rule. But on video of 189 games, players in Florida took twice as many head impacts, mostly from sticks and mostly unpenalised. In 49 high-school players wearing sensors, impact rates were the same with and without headgear, with lower impact forces. Pooled, headgear went with 30% fewer concussions in teenage girls in lacrosse and soccer, very low-certainty evidence, and girls who wore it scored higher on sensation seeking, an association.

Sources 74, 75, 76, 73, 77

Hard helmets for girls?Mixed evidence

One study modelled that girls' concussions from sticks and balls might fall if girls wore boys' helmets, but no study has tested it, and the women's game's standard is soft headgear (ASTM F3137). It isn't a helmet, and the rules on stick contact to the head still matter most.

Sources 7, 69

The riskEmerging evidence

Commotio cordis is a cardiac arrest caused by a blow to the chest at a vulnerable moment in the heartbeat. Of 23 sudden deaths or cardiac arrests in US high-school and college lacrosse in 1980 to 2008, all in men, 10 followed chest blows, 4 of them in goalkeepers wearing chest protectors. Lacrosse had 17 of 64 US cases in 1982 to 2023, second only to baseball.

Sources 78, 10, 45

Chest protectorsEmerging evidence

In the US registry, 38% of commotio cordis deaths in organised sport happened despite chest protection, 6 of them in lacrosse. Commercial lacrosse chest protectors didn't prevent the fatal heart rhythm in laboratory tests, while 3 of 12 new designs did. NOCSAE adopted a commotio cordis standard (ND200) in 2018 and finalised it in 2021; USA Lacrosse requires it for goalkeepers and boys' shoulder pads, and World Lacrosse will require it in men's and box lacrosse.

Sources 79, 80, 81, 82, 1, 2, 68

What saves livesStrong evidence

In the US registry, survival from commotio cordis rose to 58% in its most recent 6 years (to 2012), and was 40% when resuscitation started within 3 minutes against 5% later; a defibrillator on site protected against death. If someone collapses and isn't breathing normally, call 999 or 112, start CPR (cardiopulmonary resuscitation) straight away, and ask a helper to bring a defibrillator. A 2025 lacrosse consensus recommends an emergency action plan, with CPR and defibrillator arrangements, before lacrosse is played.

Sources 11, 83, 84

Lacrosse in EnglandStrong evidence

We found no England Lacrosse concussion policy, so the UK guidelines for grassroots sport apply: if in doubt, sit them out. No sport that day, an assessment within 24 hours by a healthcare professional or NHS 111 (the National Health Service's urgent advice line), rest for 24 to 48 hours, a graduated return, and no competition before day 21.

Source 85

USA Lacrosse youth playStrong evidence

The rule books include a concussion recognition tool. Red flags such as neck pain, double vision, weakness or tingling in the arms or legs, a severe or worsening headache, a seizure or vomiting mean an ambulance. "Any athlete with a suspected concussion should be immediately removed from practice or play and should not return to activity until assessed medically, even if the symptoms resolve."

Sources 1, 2

World Lacrosse eventsStrong evidence

World Lacrosse's event medical manual (November 2025): recognise, remove, rest and a graduated return, and "Any player who has been declared to have a concussion must have medical clearance before returning to play".

Source 86

Everyone: seven questions

The PAR-Q+ (Physical Activity Readiness Questionnaire for Everyone) asks about a heart condition or high blood pressure, chest pain, dizziness or losing consciousness, other long-term conditions and their medicines, a bone or joint problem that activity could make worse, and being told to exercise only under supervision. If you answer yes to any, check with your doctor or a qualified exercise professional first. If you're over 45 and not used to hard exercise, ask a qualified exercise professional before the hardest sessions, and delay if you're ill.

Source 87

After a concussion

Concussion is the commonest high-school lacrosse injury, and in one women's college team knee injuries were more likely in the year after one. Follow your rules' return before contact or live play: the UK guidelines in England, or a medical assessment under USA Lacrosse's rules. Our concussion guide has the stages.

Sources 5, 43, 85, 1

Girls and women, and after an ACL reconstruction

Women in team sports tear an ACL about twice as often as men, and lacrosse is among the higher-risk sports for teenagers. Follow the return-to-sport checks in our ACL injury guide, and do a warm-up with strength and landing work every session.

Sources 53, 41, 14

After an ankle sprain or hamstring strain

Both are among the commonest college injuries. Use our sprained ankle and hamstring strain guides, wear a lace-up brace for sport, and build up the Nordic programme before the season.

Sources 12, 13, 58, 15

Fainting, chest pain or a family history of sudden death

Cardiac arrests from heart conditions were 15 of lacrosse's 69 catastrophic events. The NHS advises seeing a GP if you've fainted, and calling 999 if you faint while exercising. See your GP before you play.

Sources 45, 88, 89, 87

Coming back to hard conditioning, and sickle cell trait

Heat, dehydration, low fitness and sickle cell trait raise the risk of rhabdomyolysis. Our rhabdomyolysis and sickle cell guides explain how to build up: a gentle first 7 to 10 days back, and never exercise as a punishment.

Source 16

Goalkeepers

Goalkeepers have died of commotio cordis wearing chest protectors of the time. Wear a chest protector meeting the ND200 standard, as USA Lacrosse requires, and make sure someone at every session can do CPR, with a defibrillator nearby.

Sources 78, 1, 2

Pregnant

The NHS advises against sports with a risk of falling or bumping your tummy, naming hockey. Leave out contact and live play with a hard ball (our suggestion), talk to your midwife or GP, and see our pregnancy guide.

Source 90

People with epilepsy

Our epilepsy guide explains that in the International League Against Epilepsy's grouping, team sports on the ground such as football, rugby and hockey add no significant extra risk. Lacrosse isn't named, but it's played the same way (our reading); wear the head protection your rules require.

Children starting out

Youth boys had more than twice the concussion rate of high-school players, and youth injuries came mostly from stick contact. Soft-ball and non-contact versions are a good start (our suggestion), and USA Lacrosse doesn't allow body checking until 14U.

Sources 32, 1

A blow to the chest, then collapse: call 999

If someone is unresponsive and not breathing normally, call 999 or 112, start CPR straight away, and ask a helper to find and bring a defibrillator. Every minute counts: survival from commotio cordis was 40% when resuscitation started within 3 minutes.

Sources 83, 11

A head injury: call 999

The NHS says to call 999 if someone has hit their head and:

• Has been knocked out and hasn't woken up, or can't stay awake or keep their eyes open.
• Has a fit (seizure).
• Has problems with their vision or hearing, or clear fluid coming from their ears or nose.
• Has new numbness or weakness in any part of their body, or problems with walking, balance, understanding, speaking or writing.
• Has a dent in their head, or their behaviour has changed, such as being more irritable or distracted.

Source 91

Suspected concussion

Stop playing: if in doubt, sit them out. No more sport that day, and an assessment within 24 hours by a healthcare professional or NHS 111. Contact NHS 111 straight away if they're being sick, feel dizzy or take medicine that thins the blood.

Sources 85, 1, 91

A possible neck injury in a helmeted player

Don't move the player unless you're trained, and don't take off the helmet or other kit: USA Lacrosse's rules say "Do not remove a helmet or any other equipment unless trained to do so safely". Call an ambulance.

Sources 1, 85

A ball or stick to the eye

Go to A&E (accident and emergency) or call 999 if the eye was hit at high speed, your sight has changed, it's very painful, you have a headache or are sensitive to light, you feel or are being sick, you can't move the eye or keep it open, or blood or pus is coming from it.

Source 92

Teeth, noses and cuts

A chipped or broken tooth needs a dentist: keep any piece in milk or saliva. Call 999 or go to A&E for a nosebleed that won't stop, clear, watery fluid from the nose, a cut that won't stop bleeding, or a bad cut on the face.

Sources 93, 94, 95

Fingers and thumbs

Go to A&E if a finger or thumb points at an odd angle, looks blue or feels numb, or bone can be seen. Get help from NHS 111 if it's painful, swollen and bruised, or stiff and hard to move.

Source 96

Knees and ankles

Call 999 or go to A&E if you heard a crack, the joint has changed shape or points at an odd angle, it's numb or tingling, or the skin is blue, grey or cold. Get help from NHS 111 if it's very painful, very swollen, or you can't put weight on it or walk more than a few steps.

Source 97

Dark pee after hard training

Dark, red or cola-coloured pee with severe muscle pain or weakness after a session needs medical help the same day. Our rhabdomyolysis guide explains why.

Heat

Heat exhaustion needs a cool place, fluids and cooling. Call 999 if someone is still unwell after 30 minutes of rest, cooling and fluids, or has a very high temperature, hot skin that isn't sweating, a fast heartbeat or breathing, confusion, a fit or loss of consciousness. World Lacrosse events have their own heat and hydration policy.

Sources 98, 86

"Girls' lacrosse is non-contact, so heads are safe"Emerging evidence

Girls' concussions mostly come from sticks and balls, women had over 3 times men's risk of concussion from a ball or stick, and head, face and eye injuries were more common in girls and women than in boys and men.

Sources 7, 37, 38

"Goggles make girls play rougher and cause concussions"Emerging evidence

After eyewear became compulsory, eye injuries fell by over 80% with no rise in total injuries. Recorded concussions rose, which the authors put down mainly to better recognition, and pooled data show eyewear makes no difference to concussion either way.

Sources 8, 73

"Soft headgear prevents concussions in girls' lacrosse"Mixed evidence

Florida's headgear rule went with fewer concussions, and pooled data suggest 30% fewer, very low-certainty evidence, but players in Florida took twice as many head impacts on video. No randomised trial exists.

Sources 74, 75, 73

"A chest protector makes commotio cordis impossible"Emerging evidence

Goalkeepers have died wearing chest protectors of the time, which didn't prevent the fatal heart rhythm in laboratory tests; that's why a new standard was written. What saves lives is fast CPR and a defibrillator.

Sources 78, 79, 80, 82, 11

"Lacrosse is more dangerous than American football"Mixed evidence

In US high schools, boys' lacrosse had the third-highest concussion rate, after American football and boys' ice hockey. One emergency-department study put youth lacrosse above youth football, but it had to estimate how many children play.

Sources 36, 99

"Any warm-up prevents injuries"Emerging evidence

The FIFA 11+ didn't reduce injuries in US high-school teams that included lacrosse, where few coaches ran it twice a week; in football, done regularly, it cut injuries by 39%. What's in a warm-up and how often it's done both matter.

Sources 50, 51, 52

"Hard conditioning builds toughness"Emerging evidence

Nine college lacrosse players were admitted to hospital with rhabdomyolysis after one conditioning session. Build up gradually, and never use exercise as a punishment.

Source 16

"Learning to body check young makes players safer later"Mixed evidence

No lacrosse study has tested checking ages, and USA Lacrosse allows body checking from 14U. In ice hockey, players who learned to check earlier weren't protected later, as our ice hockey guide explains.

Source 1