Hvordan bør man kombinere styrke- og utholdenhetstrening?

Det er anbefalt å kombinere styrke- og utholdenhetstrening for å bedre både aerob kapasitet (kondisjon) og kroppsstyrke. Gevinsten er at man reduserer helserisiko og symptomer assosiert med fysisk inaktivitet samtidig som all aktivitet i hverdagen blir enklere. Men hvordan legger man opp løpet for å balansere mengden av styrke- og utholdenhetstrening for å få maksimalt ut av begge treningsformene?

Dette spørsmålet er nøye diskutert i artikkelen «Which Comes First? Resistance Before Aerobic Exercise or Vice Versa?» i den siste utgaven av ACSM’S Health & Fitness Journal

Det blir her foreslått 4 ulike treningsregimer for parallell utholdenhet- og styrketrening:

1. Samtidig under samme treningsøkt

2. På samme dag, men en av øktene om morgen og den andre om kvelden

3. Separate treningsøkter på forskjellige dager (f.eks. styrke på mandag og utholdenhet på tirsdag osv..)

4. Spesifikk treningssykluser

Uansett hvilke rekkefølge man velger å utføre styrke- og utholdenhetstreningen så vil man kunne bedre både utholdenhet og styrke. Basert på gjennomgang av flere treningsstudier har forfatterne likevel konkludert med at hva man velger å trene først bør avhenge av hva som er hovedmålet med treningen.

Er fokuset med treningen å øke maksimal aerob kapasitet er anbefalingen å trene utholdenhet først. I ett av de beskrevne studiene hvor utholdenhetsøkten var intervall trening og styrkeøkten var sirkeltrening, viste det seg at økning i aerob kapasitet var høyere ved å kjøre utholdenhetstrening først enn å kjøre styrketrening først. Utholdenhetstrening før styrketrening kan også øke forbrenningen i tiden etter trening. Men hver obs på at hvis utholdenhetstrening kjøres først kan dette redusere kvaliteten av den påfølgende styrketreningsøkten. Vurder derfor å øke tiden for «recovery» eller tren ulike muskelgrupper i påfølgende treningsøkt.

Er hovedmålet med treningen å øke muskelstyrke og muskelstørrelse vil det være gunstig å starte med styrketrening. Forfatterne refererer blant annet til en studie hvor godt trente kajakkutøvere forbedret både muskelstyrke og aerob kapasitet (kondisjon) ved å kjøre styrkeøkt før utholdenhetstrening. Styrketrening først er også mest effektivt for å øke aerob kapasitet (kondisjon) hos eldre og i tillegg kan denne treningssekvensen øke energiforbruk samt fettforbrenning under den påfølgende utholdenhetstreningen.

Anne Berit Johnsen – Stipendiat CERG 

Taking the hits – Improving health and fitness with high contact sports

As a fan of high contact sports the last few weeks have made for some exciting viewing for me. American football’s flagship event, Superbowl XLVIII on Feb 2nd, saw the Seattle Seahawks overwhelm a hapless Denver Broncos 43-8, amazingly not the worst margin of defeat in the Broncos somewhat unfortunate Superbowl history. That same weekend also saw the start of the 2014 Six Nations, the biggest international rugby union tournament in the northern hemisphere. It was with a sad heart then that my enthusiasm the following Monday morning was met with the baffled looks and shrugged shoulders of my work colleagues. And then a realization hit me; since I had moved to Norway one year previously, I hadn’t met a single person who actually played either sport.

A quick Google search was able to lower my initial fears somewhat when I found that professional organizations exist in Norway for both American football (Norges Amerikanske Idrettsforbund) and rugby union (Norges Rugbyforbund). Following for the two sports appears to be gathering momentum, but both are still in relative infancy. The NAIF website itself acknowledges that while American football is growing in Norway, it is still not a widespread sport. I find myself asking why. Alongside the Netherlands, Sweden and Denmark, Norway is one of the tallest nations in the world. This innate physicality almost certainly lends itself well to the popularity of ice hockey in Scandinavia. High impact sports certainly have a great deal to offer individuals in terms of physical fitness.

The origins of American football rules are heavily steeped in versions of rugby played during the 19th century and as such similarities between the two are evident even today. The objective of both sports is to carry the ball, a prolate spheroid rather than the traditional spherical ‘football’, deep into the opponents half of the field. Scoring can occur in each by carrying the ball over the goal line or, under certain special conditions, kicking the ball between the tall upright goalposts located on each goal line.

The differences between the two arise from the style of play and length of the game. Rugby has more of a focus on open play, with stoppages generally only occurring when the ball leaves the field of play or a foul is committed. American football however focuses on short bursts of intense play, where the attacking team attempts to gain a relatively small amount of ground within 4 attempts, known as ‘downs’. In rugby the ball can be kicked forward, but may only be passed to the side or backwards, whereas in American football the ball can be thrown forward during a period of play, usually by a specialist known as the quarterback. Such plays generally gain more ground than a simple run of the ball at the opposing team.

A key ingredient is the emphasis on physicality and strength as well as speed. Like other team sports, there are specialized positions which mean that not everyone can play in any position during a game. The fundamental difference in these high collision sports is that specialization also involves particular size, strength and body shape characteristics. Consequently, playing individuals that don’t meet these criteria within those specialized positions is not only disadvantageous to a team, it can also be extremely dangerous. The increase in sporting professionalism in recent decades has radically altered the landscape of high collision sports such as American football and rugby. Stricter training and dietary regimes have led to an explosion in the size and strength of elite players. Current training strategies in these sports involve a mixture of high intensity interval and strength training, giving participants the best of both worlds in terms of fitness benefits.

Current size demands at the elite level may bring with them the potential for an increased strain on the body, in particular the cardiovascular system. Last year Steffes et al reported that metabolic syndrome, which describes an individual’s risk for metabolic or cardiovascular disease, was present at a similar rate in high school and college football players when compared to aged-matched general populations, however over 90% of the positive cases of metabolic syndrome were limited to offensive and defensive linemen who exhibited higher percentage body fat. In linemen, an elevated heart mass when adjusted for body size has also been reported by Uberoi et al. (2013). Karpinos et al. (2013) investigated the prevalence of hypertension (high blood pressure) between football and non-football playing American college athletes, and found that rates were approximately 10% higher in football players. Given this evidence it is likely that in American football, particularly for linemen, coaches and trainers should pay particular attention to athletes training regimes and monitor cardiovascular health closely.

While mass is a critical factor in elite athletes, those looking for a physical challenge at an amateur level will definitely find a place in either sport regardless of their size and fitness level. The emphasis on explosive speed and strength in American football and rugby means that both offer a fantastic physical workout simply during training, even outside a full game situation. So hang up those skates Norway, put on your helmet and pads, or your scrum cap, and get out onto that field.

More information for American football and rugby union teams near you can be found on the NAIF website or the Norges Rugbyforbund website.

Allen Kelly, Post Doc at CERG

Mitokondrier – avslappende hjertemedisin?

Hjertesvikt

Femten millioner europeere har hjertesvikt og sykdommen er ansett som en av de større folkesykdommene i vår tid. Pasienter med hjertesvikt kan deles inn i to hovedkategorier: de som har et hjerte som har dårlig evne til pumpe blod ut til blodårene (Systolisk hjertesvikt), og de som har redusert fylling av blod i hjertekamrene mellom hvert hjerteslag (diastolisk hjertesvikt). Begge prosessene er energikrevende, og uten energitilførsel vil hjertet slutte å motta og pumpe ut blod. I den diastoliske «hvilefasen» er det viktig at det er tilstrekkelig med tid til at hjertekamrene fylles med blod. Det betyr at det er viktig at hjertet raskt går inn i sin diastoliske hvilefase etter at blod er presset ut av hjertekamrene. Hvis hjertet bruker for lang tid til å nå sin hvileposisjon i diastolen, vil mindre blod fylle hjertekamrene før det igjen pumpes ut igjen. Selv om hjertet pumper ut en normal andel av blodet i hjertet, vil den totale mengden blod som pumpes være mindre. Dette fordi det var mindre blod i hjertet enn normalt da utpumpingen startet. Det kalles diastolisk hjertesvikt.

Mitokondrier

Mitokondriene er “energifabrikken” i cellene. Som nevnt krever også avslappingen av hjertemuskelen energi. Når nettopp avslappingsprosessen er redusert hos personer med diastolisk hjertesvikt er det logisk å studere mitokondriefunksjonen i hjertet. Funksjonen har blitt funnet å være nedsatt i ulike dyr og mennesker med hjertesvikt. Hvis vi kan finne en måte å forbedre funksjonen til mitokondriene i hjertet, kan vi forhåpentligvis bedre problemene under avslappingen til hjertemuskelen.

Vi vet at personer som trener mye har god mitokondriefunksjon i musklene, og at evnen til å produsere energi avhenger av hvilke muskler som brukes og hvilken treningsform man velger. For tiden undersøker vi om diastolisk hjertesvikt er forårsaket av nedsatt mitokondriefunksjon i hjerte celler, og om fysisk trening kan bedre dette. For å undersøke dette har vi startet et stort internasjonalt forskningsprosjekt der vi studerer hjertet til rotter med og uten hjertesvikt og rotter med hjertesvikt som driver jevnlig fysisk trening.

Trening er altså ikke bare viktig for å få hjertet til å trekke seg sammen og pumpe ut blod til blodårene, men kanskje også for å bedre evnen musklene i hjertet har til å slappe av mellom hjerteslagene. Avslapping for hjertet høres kanskje ut som god medisin?

Fredrik Hjulstad Bækkerud, PhD kandidat ved CERG

How to deal with extremely hot weather?

As the mercury sinks and the sun goes into hibernation, many of us in Northern countries dream of warmer places. But the arrival in hotter countries is not always as pleasant as in our dreams – the heat can be a shock to the system. Our Brazilian Post Doc, Marcia Alves, explains:

When the sun is at the hottest, look for a nice coconut tree with its huge shadow!

Extreme temperatures represent a health problem all over the world. While Northern Europeans suffer in January with the cold and often dry air, the countries below the Equator, like Brazil, may be extremely hot and humid. Norwegians and most people from cold countries are quite good at winter sports, or at least good at dressing for sports in very cold temperatures. But most Norwegians, and other people not used to heat, suffer when travelling to hot places, something that could ruin their holiday.

Which signs appear as children or older people get heat-related problems? How and when to do exercise? What to drink, eat or wear?

Daily work and exercising in hot weather can pose a challenge even for the fittest. Millions of people die every year due to heat-related problems, especially children and older people. In cities like Rio de Janeiro during the summer, temperatures may get close to 40oC and humidity over 90%. This affects the body’s ability to cool itself through sweating. Normally, an average adult will lose 2-3 litres at room temperature a day through sweating; but in hot and humid conditions, this could reach 10 litres of sweat a day. This means extreme loss of body fluid. But because of the humidity, the air is already saturated, and sweating loses its effect. And so, the internal body temperature could get dangerously high.

Recently, lawyers in Rio de Janeiro have started a campaign to abolish ties and suits during their daily activities – they are not as efficient when they are feeling too hot. Likewise, policemen with outdoor duties in southern states of Brazil have already changed their uniform.

But much could still be changed. This January, in Aracaju (Sergipe) in the north of Brazil, which is even warmer than southern Brazil, I saw policemen wearing long, thick, black uniforms, heavy black boots and protective vests (and carrying heavy shotguns) inside the university campus! Would they be able to run after small, fast thieves, with fewer clothes on?

The risk of heat stroke is even higher when exercising. Last year in Brazil, some policemen died during a 10 km training race due to their hot uniforms in very hot and humid weather. So, before heading to a nice warm place, remember to include in your luggage: loose, light cotton clothes, protections for the head, skin and proper sunglasses. Once you get there, avoid the hottest sun hours, look for a nice coconut tree with its huge shadow, drink litres of fluids, and eat lots of juicy fruit and vegetables. Also avoid drinking too much alcohol as this dehydrates the body further.

If you are fit, you will cope better with the weather, but do not forget to reduce the number of workouts and give yourself more breaks.

Finally, be alert to the signs of heat stress which include: fatigue, headache, nausea, vomiting, muscle cramps, thirst, etc. – especially if you travel with children or older relatives.

Now you are well prepared to have a good time!

Marcia Alves, Post Doc, CERG