The Tip

Water may be the go-to workout beverage, but studies suggest a little caffeine may help, too. Recent research finds moderate caffeine consumption can slow down glycogen depletion and help people conserve energy while working out. Caffeine encourages the body to tap into its fat sources for energy, helping people exercise longer. But it turns out a cup of Joe (or maybe even a can of Red Bull) can do more than increase endurance. Find out more at our article, Can Caffeine Boost Exercise Endurance?

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var fnames = new Array();var ftypes = new Array();fnames[0]='EMAIL';ftypes[0]='email';fnames[1]='FNAME';ftypes[1]='text';fnames[2]='LNAME';ftypes[2]='text';

try {

var jqueryLoaded=jQuery;

jqueryLoaded=true;

} catch(err) {

var jqueryLoaded=false;

}

var head= document.getElementsByTagName('head')[0];

if (!jqueryLoaded) {

var script = document.createElement('script');

script.type = 'text/javascript';

script.src = 'http://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js';

head.appendChild(script);

if (script.readyState && script.onload!==null){

script.onreadystatechange= function () {

if (this.readyState == 'complete') mce_preload_check();

}

}

}

var script = document.createElement('script');

script.type = 'text/javascript';

script.src = 'http://downloads.mailchimp.com/js/jquery.form-n-validate.js';

head.appendChild(script);

var err_style = '';

try{

err_style = mc_custom_error_style;

} catch(e){

err_style = 'margin: 1em 0 0 0; padding: 1em 0.5em 0.5em 0.5em; background: ERROR_BGCOLOR none repeat scroll 0% 0%; font-weight: bold; float: left; z-index: 1; width: 80%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; color: ERROR_COLOR;';

}

var head= document.getElementsByTagName('head')[0];

var style= document.createElement('style');

style.type= 'text/css';

if (style.styleSheet) {

style.styleSheet.cssText = '.mce_inline_error {' + err_style + '}';

} else {

style.appendChild(document.createTextNode('.mce_inline_error {' + err_style + '}'));

}

head.appendChild(style);

setTimeout('mce_preload_check();', 250);

var mce_preload_checks = 0;

function mce_preload_check(){

if (mce_preload_checks>40) return;

mce_preload_checks++;

try {

var jqueryLoaded=jQuery;

} catch(err) {

setTimeout('mce_preload_check();', 250);

return;

}

try {

var validatorLoaded=jQuery("#fake-form").validate({});

} catch(err) {

setTimeout('mce_preload_check();', 250);

return;

}

mce_init_form();

}

function mce_init_form(){

jQuery(document).ready( function($) {

var options = { errorClass: 'mce_inline_error', errorElement: 'div', onkeyup: function(){}, onfocusout:function(){}, onblur:function(){} };

var mce_validator = $("#mc-embedded-subscribe-form").validate(options);

$("#mc-embedded-subscribe-form").unbind('submit');//remove the validator so we can get into beforeSubmit on the ajaxform, which then calls the validator

options = { url: 'http://greatist.us2.list-manage.com/subscribe/post-json?u=32102b33cde61812e73270af4&id=4fee4617f5&c=?', type: 'GET', dataType: 'json', contentType: "application/json; charset=utf-8",

beforeSubmit: function(){

$('#mce_tmp_error_msg').remove();

$('.datefield','#mc_embed_signup').each(

function(){

var txt = 'filled';

var fields = new Array();

var i = 0;

$(':text', this).each(

function(){

fields[i] = this;

i++;

});

$(':hidden', this).each(

function(){

var bday = false;

if (fields.length == 2){

bday = true;

fields[2] = {'value':1970};//trick birthdays into having years

}

if ( fields[0].value=='MM' && fields[1].value=='DD' && (fields[2].value=='YYYY' || (bday && fields[2].value==1970) ) ){

this.value = '';

} else if ( fields[0].value=='' && fields[1].value=='' && (fields[2].value=='' || (bday && fields[2].value==1970) ) ){

this.value = '';

} else {

this.value = fields[0].value+'/'+fields[1].value+'/'+fields[2].value;

}

});

});

return mce_validator.form();

},

success: mce_success_cb

};

$('#mc-embedded-subscribe-form').ajaxForm(options);

});

}

function mce_success_cb(resp){

$('#mce-success-response').hide();

$('#mce-error-response').hide();

if (resp.result=="success"){

$('#mce-'+resp.result+'-response').show();

$('#mce-'+resp.result+'-response').html(resp.msg);

$('#mc-embedded-subscribe-form').each(function(){

this.reset();

});

} else {

var index = -1;

var msg;

try {

var parts = resp.msg.split(' - ',2);

if (parts[1]==undefined){

msg = resp.msg;

} else {

i = parseInt(parts[0]);

if (i.toString() == parts[0]){

index = parts[0];

msg = parts[1];

} else {

index = -1;

msg = resp.msg;

}

}

} catch(e){

index = -1;

msg = resp.msg;

}

try{

if (index== -1){

$('#mce-'+resp.result+'-response').show();

$('#mce-'+resp.result+'-response').html(msg);

} else {

err_id = 'mce_tmp_error_msg';

html = '

'+msg+'

';

var input_id = '#mc_embed_signup';

var f = $(input_id);

if (ftypes[index]=='address'){

input_id = '#mce-'+fnames[index]+'-addr1';

f = $(input_id).parent().parent().get(0);

} else if (ftypes[index]=='date'){

input_id = '#mce-'+fnames[index]+'-month';

f = $(input_id).parent().parent().get(0);

} else {

input_id = '#mce-'+fnames[index];

f = $().parent(input_id).get(0);

}

if (f){

$(f).append(html);

$(input_id).focus();

} else {

$('#mce-'+resp.result+'-response').show();

$('#mce-'+resp.result+'-response').html(msg);

}

}

} catch(e){

$('#mce-'+resp.result+'-response').show();

$('#mce-'+resp.result+'-response').html(msg);

}

}

}

>